A descriptive guide to the Museum of practical geology, with notices of the Geological survey of the United Kingdom, the Royal school of mines, and the Mining record office

Museum of Practical Geology (Great Britain) · 1867 · Historical

A descriptive guide to the Museum of practical geology, with notices of the Geological survey of the United Kingdom, the Royal school of mines, and the…

Public-domain full text preserved in the Mountain Man Mining Library. Original source: archive.org.

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Besceiptive Guide Museum Of Peactical Geoiogy, I

With Notices Op

THE QEOIOGICAI SHBYEV OF THE DHITED KINGDOM, THE ROTAI SCHOOL OE MINES,

The Miking Kecord Office,

Eobbet Huht, F.R.S.,

Foubts Edition.

ONDON: PRINTED BT GEORGE B, EYRE ASB WILLIAM SPOTTIgWOODB,

Pob Hbe Majbstt'S Stationery Ofpiob.

Ie Sixpence.

Sep .:

In addition to the detailed catalogues of special departments of the Museum of Practical Geology, this edition of " A Descriptive Guide to the Museum " has been prepared.

The first and second Editions were written by Mr. Robert Hunt, F.R.S., and the subsequent editions, of which this is the fourth, have been to a great extent revised and re-wi-itten by Mr. F. W, Rudler.

The steady sale of 15,000 copies of the various editions of these catalogues, is an evident sign of their utility to visitors.

Andrew C. Kamsay,

Director General. Museum of Practical Geology, November 1876.

Contents.

Introduction.

Objects of the Museum of Practical Geology - - - - 1

Origin of the Museum - - - - - - 1

„ of the Royal School of Mines - - - .- - 2

„ of the Mining Record Office - - - - - 2

Opening Address of Sir H. T. De la Beche - - - - 3

Reply of H.R.H. the Prince Consort - - - - 6

The Building.

The Vestibule and Hall 6

The Lecture Theatres - -.- - -6 The Library 6

The Principal Floor - - - - - - -7

The Model Rooms 7

The Galleries 7

The Laboratories - - - - -7

The Hall.

Inventory of Objects in the Hall - - - - - 8

Wall decorations, &c. - - - - - - -IS

Bust of Her Majesty the Queen - - - - - 17

„ H.R.H. the late Prince Consort - - - - 17

„ Sir R. I. Murchison - - - - - - 18

„ G. B. Greenough - - - - - -19'

„ Sir H. T. De la Beche - - - - - 19

„ Professor E. Forbes - - - - - - 20

„ Professor J. B. Jukes - - - - - - 21

„ William Smith - - - - - - 22

„ James Hutton 22

„ Professor A. Sedgwick - - - - - 22

„ Sir James Hall - - - - - - 23

„ Professor Playfait - - - - - - 23-

„ Dr. Buckland - - - - - - 24

Granites - - - - - - - -24

„ of Scotland - - - - - - -25

„ of Ireland - - - - - - -25

„ of Cornwall and Devon - - - - - 26

„ of Shapfell and Mount Sorrel - - - - 27

„ of Isle of Man, Lundy Isle, and Channel Islands - - 27

Porphyries, Elvans, Syenites, and Greenstones - - - 27

Serpentines 29

„ of Cornwall, Ireland, and Anglesey - - - 29

„ of Scotland - - - - - - 30

Marbles - - - - - - - -30

„ of Derbyshire - - - - - - -80

„ of Staffordshire - - - - - -31

„ of Devonshire - - - - - - 32

of Bristol, Isle of Man, &c. - - - - - 32-

„ of Ireland - - - - - - -3a

„ ofSc9tland - - - - - - -34

Contents.

Alabaster

Slate - „ Welsh - - - ,

„ Cornish

Sandstones

Limestones

Dolomites (Magnesian Limestones)

Grinding and Polishing Stones

Gypsum, Plaster of Paris, Cements, &c.

Tesselated Pavements ...

Crucibles

Basaltic Columns ...

Native Copper,. Cornwall

Lead Vein, Grassington

Copper-ore, South Australia -

Apatite, Canada ...

Gold-quartz, California

PuiNCiPAL Elook.

The Staircase

Synopsis of the Collection on this Floor

Central Cases, Models, &c.

Vase of Siberian Aventurine -

Russian Steel-work, &c. - -

Greological Model of London . . - .

Crystlized Slags . . . . .

Large Specimen of Agate - - . .

Ornamental Iron-castings

SiFords and Gun-barrels . - . .

Illustrations of the Physical Properties of Metals

£3ectrotype. Head of Melpomene . . .

Manufacture of Spiegdeisen . - . .

Model of Salt-mines in Salzburg Alps . . .

Swedish Iron and Steel - . . .

Stone Implements - - - . . .

Sub-Wealden Exploration - - -

Model of part of the Isle of Wight

Bessemer Steel Model - - - .

Vase in Fluor-spar - - - . .

Slab from French Bone-cavern - . .

Model of Steel Works, Sheffield

Water Barometer - - -

Model of Lead-fume Condenser ...

Cornish Mining district ...

Comstock Lode, Nevada ...

Australian Gold-workings - - .

Part of Alston Moor

Landslip at Axmouth ...

Auchengray Peat-moss

Holmbush Mine - . .

Surface of Newcastle Coal-pit

Machinery for loading Coal ... Specular Iron-ore from Ascension ... Miscellaneous mineral specimens Geological Model of Mont Blanc ...

Model of Pass of Mont Cenis Australian Gold Specimens Model of the Alps Electro-Metallurgy . - - - .

it

.

Page

Gontento. "" V

Page

Phosphor-bronze - - - - - 72

Laurentian Eozoonal Limestone - - - 72

Model of Pays of Auvergne - - - - 72

Crystalline furnace-products - - - - - - 73

Art Applications of Metals - - - - - -74

Chinese Bronzes - - - - - - - 74

Mineral-specimens -'75

Meteorites - - - - - - 75

Aluminium, Precious Metals, &c. - - .. 75

Sundry Specimens - - - .. - -78

The Minebal Collection.

British Ores, First Division - - -.- - -79

Copper - - - - - - --79

Tin 81

Bismuth 82

Cobalt, Nickel, Tungsten, and Zinc - - - - 83

Cadmium, Manganese, Uranium and Titanium - - - 84

Vanadium, Molybdenum, Chromium, and Antimony - - 85

Gold - - - - ... - - - 85

Silver and Arsenic - - - - - - 87

Foreign Ores 87

Copper - - - - - - - 87

Iron - - - -- - 90

Manganese, Bismuth, &c. - - - - -.-91

Tin - , 91

Cobalt, Nickel, and Antimony - - - - - - 92

Zinc - - - -- - - -92

Lead -- - -.- - - -93

Silver 93

Gold 94

Platinum and Tellurium - - - - - -96

Mercury and Arsenic - - - - - - 96

Specimens to illustrate the Phenomena of Lodes or Mineral Veins - 97

Colonial Productions - - - - - - -101

Australia - - - - . - loi

New Zealand - - - - - - - 102

East Indies - - - - - - -103

British America - - - - - - -104

South Africa - - - - - - -106

British Ores, Second Division - -.- -- -106

Lead - - - - - -- -106

Iron - - - - - - - 108

The Metallukgical Collection.

Copper Smelting - - - - -. - -110

Tin Smelting - - ... - .. -112

Ancient Bronzes - - - - - - -113

Zinc Smelting - - - - - - -- 113

Brass - - - - - - - - -114

Nickel and German Silver - - - - - -114

Smalts and other Cobalt colours - - - - - 1 14

Plattner's Gold Process - - - - - -115

Arsenic - -'- -- - - -115

Lead Smelting - 115

Pattinson's Desilverizing Process - - - - -116

White Lead, &c. - - - - - - - 117

Amalgamation of Silver Ores - - - - - - VVl

C50Ntents.

Mercivy

Iron Manufactore

Steel Manufacture

Page

Hobse-Shob Cabe.

Case A. —

n

$f f

if

-Diamond ... B. — Graphite, &c. C. — Coal, Jet, Amber, &c. D. — Native Sulphur E. — Prepared Sulphur - F. — Salts of Sodium ; Boracic Acid G. — Salts of Potassium, Magnesium, &c. H. — Salts of Barium and Strontium I. — Gypsum, &c.

J. — Calcite - - - ,

K. — Carbonate of Lime, continued L. — Dolomite; Apatite M. — Fluor-spar - - - .

O, — Quartz, continued - P. — Quartz, continued - ♦. — Agates - - .

Q. — Silica, amorphous and hydrous R. — Alumina ; Anhydrous Silicates S. — Anhydrous Silicates, continued T. — Anhydrous Silicates, continued ©. — Anhydrous Silicates, continued U. — Anhydrous Silicates, continued [- v. — Hydrous Silicates - W. — Hydrous Silicates, continued X. — Hydrous Silicates, continued y. — Hydrous Silicates, continued Z. — Phosphates of Alumina, &c.

Ceramic autd Vitreous Series.

Pottery and Porcelain - . -

Clay - . -

China Stone - - -

Flints - - - -

Pottery Manufacture Assyrian and Babylonian Bricks - Egyptian Figures, &c. Indian Enamel ... Ancient Greek Pottery Koman Pottery found in Britain - Roman Pottery from the Rhine Mediaeval Pottery ... Majolica Ware ... Palissy Ware ... Delft Ware ...

Chinese Porcelain . .

European Porcelain Colours used on Pottery and Porcelain Staffordshire Pottery and Porcelain Wedgwood Ware - - -

Modem Staffordshire Ware Parian or Statuary Porcelain Terra Cotta ...

Friezes, Enamelled Bricks, Tiles,. &c.

Contents.

vu

Pottery and Porcelain — cont.

Bow Porcelain - - -

Chelsea Porcelain - - -

Derby Porcelain - - .

Plymouth Porcelain

Bristol Porcelain and Pottery

Eockingham Porcelain and Pottery

Worcester Porcelain

Salopian Porcelain and Pottery -

Swansea Porcelain and Pottery -

Nantgarw Porcelain

Lowestoft Porcelain

Leeds Ware, &c. - - -

Liverpool Ware, &c.

Delft Ware, &c. - - - Glass - - - - -

De vitrified Glass - - -

Flint Glass

Bottle Glass - - .

Plate Glass - . .

Crown and Sheet Glass -

Ancient Glass ...

Ancient Venetian Glass -

Ancieift German Glass, &c.

Modem Ornamental Glass

Artificial Gems ...

Artificial Pearls ... Enamels . - . .

Mosaics

Page

The Model Rooms.

Eastern Eoom, A. Western Room, B. Small Room, C. Eastern Gallery, D. Western Gallery, E.

Lowes Gallebt.

The Palajontological Collection - - - - -171

Palaeozoic Fossils (Cambrian, Silurian, Devonian, Carboniferous, and Permain) x72

Upper Gallery.

The Palseontological Collection, continued :

Secondary Fossils (Trias, Rheetic, Lias, Oolite, and Cretaceous) - 175 Tertiary Fossils (Eocene, Meiocene, and Pleiocene) - - 177

Post-Tertiary Fossils - - - - - -177

Petrological Collection, or Collection of Rock specimens: - - 178

Igneous Rocks - - - - - - -178

Glacial Phenomena - - - - - -179

Stratified Rocks - - - - - - -179

Model of Isle of Arran - 181

Model of part of Isle of Wight - ... . 182

Proportional Section of the Himalayas - - - - 182

Sun and Planets - - - - - . -182

Antlers of Irish Deer 183

The Mining Rbcokd Office - - - - - 183

Inteoduction.

The Mrserji of Practical GtEOLOQi is intended to estibit the rocks, mineralB, ajid organic remajna, illiiatra,ting the maps and Boctiojid of the Gteological Sorvet of the Ukited Kingdom ; also to exemplify the applications of the Mineral productions of tbeee Islands to purposes of use and ornament ; — to show, in fact, the results which have been obtained from the efforts of thont and industry brought to bear npon the raw materials with which Nature

The collection, therefore, divides itself into two principal groups.

I. TuE Naturai Materials — GeologicalandMineralogical— which may he studied aa to thoir lithological character, their geological order, or their mineralogical constitution.

II. The Artificial Productiohs, exhibiting the results of human, labour aided by the discovery of science.

There are also three Becondary, but important diviaions.

The Mechanical Appliasces, which are used in working the raw materials.

The Historical Specimeks, which have been added with the view of preserving, in juxtaposition with modem m&nufacturea, the pro- ductions of other ages and countries for purposes of comparison.

The Foreign and Colonial Minerals imported into this country in the natural state.

There are some other objects, valuable from their educational character, couHtitutiag a miacellaneons group, which cannot bo bronght withiu any of the above divisions. These are geological and mining models showing the various phenomena which occur iu those diatricts which have been explored by man in his search for mineral treasure.

Such are the objects of the Museum of Practical Geology, which originated from a representation submitted in July 1835, by Sir Henty Thomas De la Beche, to the Chancellor of the Exchequer, The Geological Survey hud recently been commenced in connection with the Ordnance Survey of the United Kingdom ; and it was suggested that means therefore existed of collecting " Specimens of the Application of Geology to the useful purposes of Life."' The importance of a Museum, which should fairly illustrate the mineral productions of the country, and show their commercial value, was at once recognized. The suggestion of Sir Henry De la Beche received the approval of the Government, and he wal authorized to proceed in the development of his idea.

In 1837, Lord Dnncannon, Chief Commissioner of Woods and Forests, allotted apartmenta in No. 6, Craig's Court, to receive the nucleus, around which has gathered the present extensive collection. The MusECM of Econohic Geology, as it was first named (no* the Museum of Fsachcal Geology) was placed under the direction otiSa. originator, and within a short period ttie cotSitfyo. V;c*jni>i wi valuable and important, that it was tiuoagiit eceaawrj X.- w-s-o*. 40332.

2 Introduction.

curator, and accordingly in 1839, Mr. Eichard Phillips, F.B..S., was chosen for the oflBce. Advantage was taken of Mr. Phillips' abilities as a chemist, to unite analytical investigations with his duties as curator. A laboratory was attached to the establishment ; analyses of minerals, rocks, and soils were made, and instmction was given, to a limited number of students, in chemistry and metallurgy. From this originated the Koyal School of Mines (for- merly called the Goverxmext School op Mines), united with this establishment, in which such branches of science are taught as have an especial bearing upon our mining and metallurgical industries. The office of curator and chemist was retained by Mr. Bichard Phillips until his death, which occurred upon the day on which the present building was opened.

As the Geological Survey progressed, the Museum was rapidly extended. The original idea of a collection so practical in its cha- racter, and so peculiarly adapted to the wants of a great commercial and manufacturing community, being felt to be a correct and nsefiQ one, presents flowed in from persons interested in those particular branches of industry which it was intended to illustrate.

In August 1838, a representation was made to the Government by a Committee of the British Association for the Advancement of Science, to the effect that with a view to prevent the loss of life and of property which will inevitably ensue from the want of accu- rate Mining Eecords, it is a matter of national importance that a depository should be established for the collection and preservation of such Mining Records of subterranean operations in collieries and other mining districts." The result of this was that an office was established, under the title of the MnoNG Record Office, and Mr. T. B. Jordan was appointed the Keeper of Mining Records in 1839, which office he hela until 1845, when he was succeeded by the author of this Descriptive Guide.

In 1845 the Geological was separated from the Ordnance Survey, and placed, with the Museum of Practical Geology, under the De- partment of Woods and Forests. The necessity for fitting accom- modation became so pressing that, with as little delay as possible, the present building was erected by Mr. J. Pehnethome, for the Office of Woods and Works, the Chief Commissioner at that time being the Earl of Lincoln (the late Duke of Newcastle). It WM opened to the public in May 1851, by His Royal Highness the late Prince Consort, and in November in the same year Sir Henry De la Beche delivered his inaugural discourse at the opening oi the School of Mines.

The Geological Survey — now under the guidance of Professor Andrew Crombie Ramsay, LL.D., F.R.S., as Director-General — has, in its progress been constantly adding to the stores of the Museum of Practical Geology, and it is now especially rich in those illustra- tions which show us the progress of life upon this globe, and mark its great mutations. Its PalaBontological collections, whether re- garded as objects of scientific interest, or as guides to the searcher £)r mineral treasures, are of the highest value. The mineral groups, either in their earthy or the metalliferous divisions, have a large commercial interest, and must convey to all attentive minds an instructive lesson.

It is to guide the public in their examination of those specimens, — to inform them of their natural peculiarities, — and some of the methods by which they are rendered practically useful, that the present work has been undertaken. This volume must not be mis- taken for a Catalogue of the Museum; it is simply a Descriptiv©

Istbodvotiok. 3

Gnido to tlie various gronpa of epQcimens wkich it containg. Hence it is thaS, althongt Bufficient indications are given of the position in wbicli tite examples described are to be found, a Rystem of grouping the objects nnder general headings has, in most caaes, been adopted as the easiest means of cammuuicatiag the largest amoant of infurmfttioa within a limited apace.

As considei'ablo interest must eventnallj attach itself to ereiy circumstance connectect with tho first eroeriment of a popular educational character made by the British uoveminent, it has been thonght desirable to put on record some account of the opening of this Institution . ,

On Monday, May 14, 1851, the Museum of Practical Geology was formally opened by His Eoyal Higbneaa tbe late Prince Consort, in the presence of a large circle of the leading members of the world of Bcienco, and of the aristocracy. The Piinco Consort having taken the chair, on the principal floor. Sir Henry De la Beche, as Director of the etablisbment, approached His Boyal Highness and read the following addresH :

" We, the officers of the Muaeum of Practical Geologj, deeply sensible, in common vith our fellow conDtrymen, of the earnest and increasing desire of your Bajol liigbiiess to patronize and aid all tlial may advance the happi- ncBE and promote tho pragresa of our nation, auil not only of this, bul also of other lands, as is abuadlntl; proved by the untiring eKertioiis whioh have brought GO vast u design ts an Bshibition of Industry of all Kations to that successful iesuc which will make it memorable in the annals of our countij, request permission to express our respectful banks for tbta establisbmcot having been considered one to bo included among those whiixh have public advantage aud progresE for their objects, and as such deemed worthy thi day of the presence of your liojal HigluiesB. The Museum of Fracticid Geolpgy was foauded, in 1835, in consequence of its baving become evident, during the earlier progress oE the Geological Survey of Great Britain, that numeroua opportunities presented themselves, which it was not desirable to forego, for ijjnstrating the applicationB of geology to the nseflil purposes of life. It wna considered that collections should be made with that object, and be arranged with every reference to instruction, so that those interested might be enabled to judge how tor onr known mineral wealth might be rendered available for any uodeitakiug they might be required to direct, or were anxious to promote, for the good or ornament of their comitry.

" As geological surveys necessarily include information which, if rightly interpreted, is of great value to agriculture, care was also taken to render tho museum useful in that direction, so that, whether tlie districts esaniined were agricultural or mining, they should alike receive attenliou. To promote a knowledge of the properties of soils, as well as to efibet an examination of the various arm of the metals, and of other uuneral products of importance to the possessor of mineral property, the miner, the engineer, the architect, aud of those interested in aits and manu&cturcs Kenerally, a laboratory in connection with the mnseoin became necessary. The laboratory has frequently proved useful to the departments of the Govemnjent. We may point to the inquiry for the Admiralty into the coals of this country best suited for our Sleara navy, the third and final report on which has just been laid before the Parliament, as among the last, and probably not the least, important investigations undertaken for the Government at thin establishment Tbongh much has been aocom* plished f or our coUcotious by the progress of the Geological Survey, much also has been cBiiOled by the kind consideration of the vonuaa cWfls*. tS-'Aut pubUo interested in our advance, and, in conBeqftecce,V'* %sa ' inve swollen the colleclionH to their pieaent slaXfi. "iJiaws c'

t.'i

Mthoduction.

pTMents have been alike extensUe and valuuble, and ne feel no little pride is moluding your Royal Higtueas uinong those who hare uidad us with donatioiis as well at a dine when the inoseutn was in its in&acy, located in a cooipmr lively obscure liujldin, as nov, when, in a more approprinle structure the rarioui object Ibr which it was cstabliahed can be effectively carried ODt The museum bad been $o for developed iu ]B4Dthat, in cooaeqacnce of i represents don of a committee of the Association foi the Adrimccment of Science, the Governmeiit directed an Office of Miuinf; Itecorclti to be attached' to it ; and it is hoped that thereby, as was slated by thai committee, many of those neat losses of life and of capital which have been sustiuDed &om want of lUOD records may, to a great eitenl, be avoidtsi. A valuuble coUeutim of Eueh records has been already formed ; und . we have also, in this departmauL to acltnowledge the aid which your Royal Highness has afforiled ns, as Low Warden of the Stannaries, by pcrmlttiDg copies of the wining plans and sectioiM of the Duchy of Cornwall to be taken for this office. It 1:1 but right, aleo to elate, that from the mining intereeta generally we have experienced every couragemenl, with regard to our iniuin records, ho that ne may hope, M bO distant date, have collected on aniount of practical information on this heal especially vnluabla as regards old workings and mines which have bten abandoned.

" Thougb many years since, in 1839, (he Government sanctioned lecturai ijD connection with the museum on analytical chemistry, sgricuitural chemistrji metalluigy, mining and mineralogy, the want of proper accommodation ha until the present time, prevented their delivery. Kow, however, that u theattS for them has been provided, it haa been deemed ex{>edient to extend thcM lectures, so a)i to embrace induction of a cliarscter resembling that giTen is Foreign Schools of Mines, and which, while it should be adjusted to the wants of this comitry, should also have reference to the mineral wealth of the empin

" Several memorials from important mining dietricli hnve been presented tO' the Gavemment, to ufford facilities at this establishment for inBtmclion aT

able for the mining interests, one of so much magDitude in this conntrr 1

valueof (he mineral prodoels of Great Britoin and Ireland being now esluiM.

at 35,000,000.* per antinm, the various products taken as nearly as possible In their first state. It has been further estimated by competent foreign writers that the annual value of the mineral substances raised io the British islands is equal to abont fbur-nluths of that of bU Europ?, including; these islands.

" To your Royal Highness it would be needless to point out the bearing of the Mining Schools of France, Saxony, Russia, and Austria upon the mineral resources of those countries, the useless expenditure they prevent, and the real produetiveiiega the]- protnote. To those whose duty it is to pass among our mining districts, it is oflea matter of regret to find many a powerful mind struggling with a want of knowledge of that which others have accomplished, or may be now doing. Great as the achievement* of uniustnicted men have sometimes been in such diistricts, Ihey would hove been atiU greater, and the instances would have been more multiplied, had better opportunities been afforded.

" While it is proposed to receive pupils by regular courses of study, — to teach by means of lectures, — experimental researches in the laboratory, — and also by the aid of the Geological Sursey in the field, the coHectioBS of Ihe museum will be gratuitoosly open to public view. Your Royal Highness will have seen, by inspection of these colleotionfl, that they are alike scientific and practical. We feel that in this we are not likely to have erred in the opinion of those who believe, as we do, that the greater the amount of scieoee, Ihe greater will be the amount of lis application. In addressing your Royal Highnesa on this Bubjecl, we know that we are addressing a Prince who feels a deep interest iu it, and who justly appreciates its general bearing.

cscluding K. H.

Introduction. 5

" That the honoured consort of our beloved Queen may long continue to exercise that beneficial influence which his enlarged views and exalted station command, is the earnest and sincere hope of the officers of this establishment."

Sir Henry de la Beche, having concluded reading the address, presented it to the Prince. His Eoyal Highness acknowledged it in the following terms : —

'' In thanking you for the address which you have just read to me, I would also express the sincere gratification with which I witness the opening, — in a form more likely to make it generally and practically useful, — of an institu- tion the progress of which I have long watched with much interest, and the want of which has been long felt in this country. I rejoice in the proof thus afforded of the general and still increasing interest taken in scientific pursuits; while science herself, by the subdivision into the various and distinct fields of her study, aims daily more and more at the attainment of usefiil and practical results. In this view it is impossible to estimate too highly the advantages to be derived from an institution like this, intended to direct the researches of science and to apply their insults to the development of the immense mineral riches granted by the bounty of Providence to our isles and their numerous colonial dependencies. It will always giv me the greatest pleasure to hear and, as far as I am able, to contribute to, the continued success of the Museum of Practical Geology."

A DESCRIPTIVE GUIDE, &c.

The Bthlding.

The edifice itself must be regarded as one of the illustrations of the main object in view. It was designed by Mr. James Fezme- thome, who, co-operating with Sir Henry De la Becfae, e9ideavt)iired to make it, in all particnjars, an illustration of the applications of Geology.

The Piccadilly front of the Musenm is constmcted of Anston (Yorkshire) Dolomite or magnesian limestone, of the same kind as that employed for the exterior of the new Honses of Parliament. The Jermyn Street front is composed partly of the same stone, and partly of Suffolk bricks.

The steps at the entrance are of the red granite of Peterhead, and at the doorway is a slab of slate from the Penrhyn quarries of North Wales. The pavement and steps leading into the hall are of Port- land stone ; the base of the sides of the vestibule is of Irish granite, the upper portion of polished Derbyshire alabaster ; and the pilasts on either side at the heads of the steps from the vestibule are of grey Peterhead granite. As all these stones have their representatives in the hall, particulars respecting them will be found under their special heads.

The Yestibule and Hall.

These are devoted to the exhibition of the building and ornamental stones of the United Kingdom, with such miscellaneous articles as could not be conveniently placed on any other floor.

The Lectdke Theatres.

The large theatre is situated immediately north of, and is entered from, the Hall. It is constructed for seating 500 persons, but on many occasions, especially when lectures are delivered to the work- ing men, considerably more than that number have been accommo- dated. In this theatre most of the lectures to the several classes of the EoYAL School of Mines are delivered ; but a smaller room on the upper floor of the buildiDg is especially devoted to certain classes.

The session commences in October and terminates about the end of June. A prospectus and information may be obtained on appli- cation.

The Library.

Beyond the theatre in the Piccadilly front of the building is the Library of the institution, containiog upwards of 25,000 volumes of books devoted to the sciences taught in the school. These are available for the use of the students of th Bcucjoi. ore "S&re:t%,.Tid,

THE BtriLDING. 7

— upon special applioaiiou, stating tho object in view, — tlie books can be consulted fay other inqnn-ers. Aa moab of the important periodioala relating to science pnbliflhed in this conatry, on tte con- tinent, and in America, are regalarly received, and also the new pnblicationa bearing on the aciencea taught, tho number of booke very rapidly increaBes.

The Petscipal Floor op the Museum. In this dopartnionfc will ho found the collection of metalliferouB rainerala, witli illoBtrations of metallurgy; the earthy minerals and their useful applioations, exemplificationB of tho conditiana under which metalliierouB orea occur in notore. la fact all the principal , objecta which hare a relation to Practical Geology will ho found iii this important diTisiou of the Museum.

Tbe Mosel Rddius.

At the northern end of the principal floor are two rooms which, with a small supplemental? room on the lower gallery, are devoted to mining and metallurgical models. Severnl, however, ai-e dialri- bnted aronnd tho principal floor of fho Museum.

A Descriptive uatalogue of tbe Models can be obtained in the

The Gallebies.

The lower and the upper galleries are devoted to scientific geology. The fossil collections will be found, commencing on the weatertt side of the lower gallery, with the earliest forms of organization, and prooeediug in an ascending order to the upper one. A Ca(- logue of the c<lectioa of Poseils, with an explanattiry Introduction by Profesaor Huxley, is published. In the recesses of tho upper gallery will be found a oolleotjon of British Rock specimens, of which a special catalogue is published.

Tub Gbological SnavEY, and the MiuTNt Rbcohd Oehces will bo found at the aonthem end of tho upper gallery.

The Laeobatoeies.

The chemical studies of the students of the Boyai School of Mines, under tho charge of Dr. Frankland, are coudncted at the Science Schools, South Kensington. Tho two Laboratories in the building in Jermyn Street, one on the basement, and tbe other at tho northeru end of the upper gallery, are devoted to Metallurgy nudor the direction of Dr. Percy,

Studente of the School of Mines receive practical instruction in Biology under Professor Husley, and in Physics under Dr. Guthrie, at the Laboratories at South Kensington.

8 The Hall.

The Collections.

The Hall.

Although it is foreign to the general purpose of this guide-book to insert special catalogues of any of tne collections exnibited, it has yet been considered desirable to introduce the following inven- tory of the objects in the Hall, since this department — unlike most other sections of the museum — is not provided with a catalogue of its own. In the arrangement of this inventory no system of classi- fication has been attempted, but the convenience of the visitor has alone been consulted, and the objects have consequently been num- bered in that order in which it is believed they will be found with the least possible difficulty. The numbers commence on the right- hand side of the steps on entrance ; they are first carried round the walls, and are thence continued to the objects in the general area, passing fom the western side along the northern end to the eastern side, and finally around the central pavement, terminating with No. 232, at the foot of the left-hand or western staircase.

Appended, in most cases, to each item in the inventory ia a reference indicating the page of this guide-book at which a general description of the object under examination may be found ; and it is hoped that with this system of reference no difficulty whatever will be experienced in immediately finding the information required respecting any object in this department.

In\entobt of Objects in the Hall. No.

1. Column of porphyritic granite ; Galway, Ireland (pp. 25, 27) ;

supporting No. 2.

2. Bust of the late Sir E. I. Murchison, Bart., K.C.B., by H.

Weekes, R.A. (p. 18). Bequeathed by Sir R. I. Murchison.

3. Column of red granite; Trowleswoithy, Cornwall (p. 26);

supporting No. 4.

4. Statuette in terra-cotta inscribed "Mich. Bysbrack, 1753"

(p. 150).

5. Column of marble ; Matlock, Derbyshire (p. 30).

6. Large crystal of Quartz (p. 131) ; at foot of Case III.

7. Column of marble; Chudleigh, Devon (p. 32).

8. Column of marble ; Babbacombe, Devon (p. 32).

9. Polished slab of pink granite; Aberdeenshire (p. 2.5).

10. Ornamental pedestal of granite; Fremator quarries, Devon

(p. 26) ; supporting No. 11. Presented by Wagstaffe & Co.

11. Cast in plaster of Paris of a large Greek vase obtained at

Naples by Sir Woodbine Parish, K.C.H., by whom it was presented (p. 43).

12. Largo circular slab, or table-top, of dolomitic or magnesian

conglomerate ; Draycot, near Wells, Somersetshire (p. 33).

13. Column of marble ; Lligwy, Anglesey (p. 33).

14. Slab of ammonite marble, consisting of a mass of Ammonites

Smithii, Sby., and A. jplanicostatus, Sby., cemented by dark- coloured argillaceous carbonate of lime; Lower Lias of Maraton, Somersetshire (p. 33).

15. Spirallyflnted colamn of Penrhyn slate (p. 35) ; Hnpporting

Spirallyl

16. Boat of Charity in Watcombe teim-cotta ; Devonshire. Pre-

sented by the Watciombo Terra-cotta Co., Limited (p. 154],

17. Polished block of Tiree marble ; Hebrides (p. 34).

18. 19. Two polished slabs of Verd anti(|ne marble (p. 29).

20. Inlaid slab of steatite and Berpentine ; Lizard diatrict, Corn-

wall (p. S9).

21. Slab of black Derbyshire marble, inlaid with " V. B." in red

marble (p. 30).

22. Colnwn of brocciatod marble ; Isle of Man (p. 33) ; snpportiiig

-No. 23.

23. Bust in terra-Mtte (p. 150).

24. 25, 26. three patent iron tnbea, one of which ia 13 ft. 4J ins.

in length, and 7 ins. in diameter. Majmfartnred by Mesera, Selby and Johns, Smethwick; and prcaented from the Great Exhibition, 1851, by Messrs. Bird & Co.

27. Inlaid table-top, containing 1,012 specimena of modem

marbles (p. 30), agatea (p. 133), alabasters (p. 34), &c. Col- lected by Professor Corw, of Boma

28. Inlaid table top, containing 1,012 specimens of ancient marbles

(p. 30), agates (p. 133), alabostors (p. 34), &c. Collected among the ancient bnildings of Italy, G-reece, and Africa by Pro- feasor Corsi, of Eome, and referred to in his work"Delle Pietre Antiche."

29. Largemaa-sof Websterite (p. 129); NewhaTen, Snaaex. Under

30. Bar of best Staffordahiroii-on, measuring 20 ft. lin.ia length,

and 7 ins. in diameter; and weighing 1 ton, 2 ewt., 3 qra., 12 lbs. Boiled at the works of Mesara. J. BagnaH & Sons, West Bromwich, and presented from, the G-reat Exhi- bition, 1851, by Messrs. Bird & Co. (p. 119).

The screens which ornament the wall on this aide are described at p. 16.

31. Large mass of purple copper ore, or Bnntkupfererz, from

near Disco, Greenland (p, 89). Presented by Sir W. Trevelyan, Bt., and Messrs. Eobinson and Westenholz. Beneatb Case III.

32. Boulder of hiematite, or red-iron ore, from the base of the New

Bed Sandstone, Porlook, Somersetshire (p. 108). Presented by the late Mr. E. Rogers. Beneath Case III. 33 & 33i. Poliahed slabs of granite; Killiney, Ireland (p. 25).

33. Mass of red oiide of copper, from the Burra Burra mines,

Sonth Australia (p. 101). Presentedby thedirectors. Beneath Caae III.

35. Colnmn of Derbyshire marble (p. 30).

36. Pilaster of red Peterhead granite (p. 25).

37. Colnmn of black marble ; GalwBy, Ireland (p. 33).

38. Slab of limestone, exhibiting ripplo marks ; from the Middle

Purbeck beds, Dardlestone bay, Swaiiage {p. 38).

39. Terra-cotta figure of Galatea (p. 150), executed ajid presented

by Mesars. Minton & Co.

40. Casts of weapons and armour in bronzed plaster of Paris, from

Paris (p. 43). On the wall above.

41. Polished section of septarium from the Oxford clay, We-

month (p. 45). Inlaid with sectiona oi i " -" -

lemuites (p. 176).

42. Colnmn of marble ! Nether Hatldon, DtTbyehirc (p. 30).

*ri. Pilaster of aerpentinoua marljlo; Ballinahiufh, Galway (jp. 29).

44. Pilftster of marble ; Babbacombe, Devon (p. 32).

45. Cube of calamine, or carbonate of zino, from the Vieille Mon-

tagne Company's works, near Aix-ln-Chapelle (p. 92), Pre- sented by the Company-, from tliB Great Exhibition, 1851. Beneath Case IX.

46. iarge 6-inch bar of Staflbrdahiro iron, rolled by Meaara. Bag-

naJI and Sone, West Bromwich ; and preaentcd from the Great Exhibition, 1851, by Messrs. Bird A Co. (p. 119). T neath Case IX.

47. Slab of foasilifcTonB Portlaitd stone, from Tiabury, Wills .

(p. 38). Beneath Case IX., western aide.

48. Pilaster of Clonony marble ; King's Co. Ireland (p. 33).

49. Portion of a Iwge Sigillaria from the coal nioaBnrea of Soutli

Staffordshire. Presented hy Samnel Blat-kwoll, Esq.

50. Large block of cannel coal from Haigh, near Wigan, Lanca-

shire (p. 125). Presented, from the International EihibitiOD, 1862, by the Earl of Crawford and Balcftrres.

51. Portions of large fossil plants, from tha coal raeasiirea of Syd-

ney, Cape Breton, Britith North America, Presented ly the late Earl of Dondonald, G.C.B.

52. Specimen of Simngodendron Bogliahnee, from Boghall, near CresBwell, Northumberland. Figured in Sternberg's "Flora der Vorwelt," pi. XXXVU., fig. 5. Presented by Sir W. 0. Trevelyan, Bt.

53. Portion of the of a fossil tree from the dirt bed, Portland

(p. 38). Presented by T. Foot, Eaq.

54. Oolamn of marble ; Nether Haddon, Derbyshire (p. 30).

55. Silieified fossil wood, from the deeert, near Cairo (p. 134). Pre-

sented hy the late Dr. Bnist. 56 & 57. Specimens of similar fossil wood, polished.

58. Column of marble ; Sheldon, Derbyshire (p. 30) ; supportitig

No. 59,

59. Small oolnmn of volcanic ash from the Quantock Hills, Somer-

setshire. Presented by the Bt. Hon. Lord Tannton.

60. Polished marble alftba (p. 30).

61. Copy of the bast of the etatne of Antinons as Bacchus, sculp-

tured in Anston dolomite by Mr. G. H. Smith (p. 39). The stone presented by Mr. Grissell.

62. Polished circular slab of a septarinm from the Oxford clay,

Weymouth (p. 45).

63. Column of coroiline marble; Tideswell, Derbyshire (p. 30).

Supporting No. 64,

64. Plaster cast of of the late Professor 3. B. Jnkes, F.B.8.

(p. 21), by Joseph Watkins.

65. Slab of alabaster from near Carrickmacross, Co. Monaghftn,

Ireland (p. 34). Preeented by E. J. Shirley, Esq.

66. Octagonal slab with inlaid geometric design in varieties of

marble (p. 30).

67. Polished slab of serpciitino ; Lizard district, Cornwall (p. 29).

68. Column of marble ; Kenry, Limerick (p. 33) ; supporting

No. .

69. Bust of William Smith LL.D., hy M. Noble (ji, 22).

70. Polished slab of stalogamitio aragonite, Irom Eeni-aouef,

Egypt. Presented by the late Princo Consort.

71. Poliwied circular slab of stalagmitic aragonite, from Beni-

Boaef, Egypt. Presented by the lata Prince Consort. .

Isvextort. 11

72. Copy of the etatne of the PameEe Herculee, Bculptured in

Portland atone by Mr. C. H. Smith (p. 38). The Btone pre- eent-ed by Meears. Stewards & Co.

73. Specimen of Ammioniieg aiga/niuvB, from the Portland beda (p. 38}. Presented by a. Smith, Esq.

74. Foliahed table-alab of aerpentinous marble ; BdUinahinch,

Galway {p, 29), Behind aWtiie of Heroulea. ?S. Column of marble ; Ipplepcn, DeTonahiro (p. 30) ; supporting

No. 76. 76. Bust of James Hutton, M.T)., by Patric Park (p. 22). "7. Polished slab of rosewood marbie; Derbyahire (p. 30).

78. Inlaid pavement of Keeue'a cement, copied from a Roman

moaaio paTement, discovered in 1795, in a villa at Bcampton, near Lincoln (p. 44).

79. Polished slab of encrinital marble j Derbyahire {p, 30).

80. Oolnnm of marble; Wirlra worth, Derbyshire (p. 30).

81. Column of eacrinitftl marble ; Flagg, Derbyshire (p. 30).

Supporting No. 82. 8-2. Tawa of red Derbyshire marble (p. 30).

83. Polished taple-top of sei-pentine veined with steatite ; Lizard

Cornwall (p. 29).

84. Pedestal of red Peterhead granite (p. 2.5) ; supporting

No. 85.

85. Copy of the Giustiniani Minerva, ai

dolomite by Mr. C. H, Smith (p. i. by Messrs. W. & J. Freemen.

86. Column of marble; Aahford, Derbyshire (p. 30).

87. Tazza of black Derbyshire marble (p. 30) ; inlaid with floral

border in coloured marbles.

88. Colnmn of alabaater ; Chellaston, Derbyshire (p. 34).

89. Column of marble ; TideswoH, Derbyshire (p. 30) ; support-

ing No. 90.

90. Cube of serpentine ; Portsoy, BanHshire (p. 30). Pi'e=ented

bytheBarlof Seafleld. Supporting No. 91,

91. Obelisk of Portsoy Serpentine (p. 30).

92. Colnmn of dark green serpentine from the Lizard, Cornwall,

(p. 29) ; aupporting No. 93.

93. Font in red and green varieties of Corniah Serpentine (p. 29).

94. Colnmn of grey granite ; Aberdeen (p. 25) ; sapporting No. 95.

95. Copy of a buet of Bubastia in greenstone, from Llanwnda,

Fishguard, Pembrokeshire i by Mr. C. H. Smith (p. 29).'

96. Portion of a tesselated pavemtnt, by Mcaars. Wyatt, Parker,

& Co. (p. 46).

97. Portion of an inlaid table-top of Derbyahiro and Stalfordshire

marbles, made mid presented by the late Mr. Milne, Aehford, Derbyshire (p. 31).

98. Colnmn of marble ; Allport, Derbyshire (p. 30).

99. Pilaster of encrinital marble ; llicklow Dale, Derbyshire

(p. 30). ion. Column of Clonony marble ; King's Co., Ireland (p. 33). 101 & 102. Polished stat>3 of stalagmitic carbonate of lime ; Suisan Bay, California. Presented by E. Seyd, Esq.

103. Lnrge mass of crystallized quartz (p. 131), coating galena

(p. 107), and flnor (p. 131). From Weardale, Durham. Presented by W. B. Beauniont, Esq., M.P.

104. Coloured Bketch on ground of Benson and Logan's metallic

cement (p. 45). On wall nbove.

105. Oomico of grey granite, ornamented in intaglio and gilt.

106. Table with inlaid top of Devonshire marbles (p. 32).

107. Table with inlaid top of Derbyshire and Stafl'ordshire

marbles (p. 31). Worked by the lato Mr. Milnoa and Mr. Bcdfem. 108. Column of marble; AUport, Derbyshire {p. 30).

1109. Pilaster of Ipplepen marble ; Devon (p. 32). . 110. Column of marblo ; Allport, Derbyshire (p. 30).

J 111. Polished slab of red Peterhead granite (p. 25),

I 112. Polished slab of grey granito; Aberdeen (p. 25).

113. Portion of a vein of auriferous or gold-bearing quartz, from the GrasH Valley, Nevada connty, California (p. 49). Pre- sented by r. Ontherwood, Egfj. ' 114. Stereo-chromic painting, by Echtor, of Munich (p. i5). On

wall atiove.

115. Column of marble ; Wirkaworth, Derbyshire (p. 30).

116. Pilaster of serpcntinoua mai'ble ; Ballinahinch, Galway (p. 29).

117. Column of marble ; Miller's Dale, Derbyshire (p. 30).

118. Polished slab of sorpentinouB marble ; Ball inah inch, Galwoy

(p. 29).

119. Pedestal of red Peterhead granite (p. 25) ; supporting

ISa. 120.

120. Cast in plaster of Paris of the Apollo Belvedore (p. 43),

121. Polished slab of enerinital marble ; Derbyshire (p. 30).

122. Column of alabaster ; Chollaston, Derbyshire (p. 34).

123. Specimens of Penmaen-mawr stone ; Caernarvonshire (p. 29).

Beneath Case VII.'

124. Mass of copper glance (p. 80), with iron pyritos {p. 108),

and quartz (p. 131) ; from Tomnadashan copper mine. Loch Tay, Perthshire. Presented by the late Morqais of Breadftlbane. Beneath Case Vil.

125. Pilaater of red Peterhead granite ; Aberdeenshire (p. 25).

126. Section of a septarinm (n. 45). Under Case VI.

127. Polished slab of Devonshire marble (p. 32).

128. Polished slab of Derbyshire marble (p. 30),

129. Polished slab of dolomitic couglomerate ; Coity, Glamor-

ganshire (p. 33).

(Noa. 127, 128, and 129 are beneath Case V.)

130. Block of Jasper ; from Trutham, Cornwall (p. 133). Pre-

sented by Montague Parker, Esq.

131. Polished slab of Dovonshire marble (p. 32).

132. Polished slab of Plymouth marble (p. 32).

133. Frame containing eight slabs of Irish marblo (p. 33). Prfe,

sented by Messrs. Manderson, of Dublin.

(Hos. 131, 132, and 133 are beneath Case IV.) N.B. — The southern end beneath the window is oocn- pied by a collection of slates, described at p. 34.

134. Polished slab of porphyritic granite ; Cornwall (p. 26)

135 & 135a. Polished slabs of elvan ; Withiel, Cornwall (p. 28). 136, Polished slab of schorl rock ; Bocho, Cornwall.

Invbntotit. 13

137. Circular inlaid table-top of different vai'ietiea of Corniah

seroentine (p. 29). On wail above.

138. Inlaid slab of piecea of agato (p. 133), jasper (p. 133), por-

phyry fp. 27), &o., found as pebbles oa the beaoh at Aberystwith, Cardiganshire. On waU above.

139. Colnmn of Plymouth marble (p. 32).

140. Polished slab of raarble ; Kitley Park, Yealmpton, Devon

(p. 32). Ul. Oolumn of Plymouth marble (p. 3 142. Column of marble ; Stoi ""'" l-iS. Slab of Shelly marble, .

(p. 30).

144. Poliflhed slab of Devonshire marble (p. 32).

145. Column of black mable ; Moolfra, Anglesey (p. 33).

146. Column of marble; Wetton. Staffordshire (p. 31); sup-

porting No. 147.

147. Statuette of Bailey's Flora, in Coade'a terra-ootta (p. 150).

148. Pedestal of gi-ey granite ; Carnaue, Cornwall ; with base

of porphyritio granite, from Lamoma Cove, Ijand's End (p. 26) ; supporting No. 150.

149. Tazza of red serpentine, the shaft entwined by a dolphin of

green steatitio aerpentine ; both from the Lizard, Cornwall (p. 29). Worked by Mr. Pearoe, of Truro.

150. Column of grey scnorlaceoua porphyry, from Lanlivery.

Cornwall (p. 27) ; supporting No. 152.

151. Cabe of serpentine ; Portsoy, Banffshire (p. 30). Presented

by the Earl of Seafield. Supporting No. 153.

152. Tazza of red Aberdeen granite (p. 25).

153. Large pedestal and tazza of red Peterhead granite (p. 25).

Worked, with mauyof the other Scotch granites, by Messrs. McDonald and Leslie, Aberdeen.

154. Column of aehorlaceoua porphyry (Luxullianite), from

Lnsullian, Cornwall (p. 28) ; supporting No. 155.

155. Vase of Derbj-shire fluor apar (" Bine John,") one of the

largest and finest examples known, having been executed for a royal personage at a cost of nearly 100!. (p. 63).

156. Pedestal of steatitin serpentine, with base of red and green

serpentine, both from the Lizard, Cornwall (p. 29); sup- porting Nq. 157.

157. Cube of granite ; Portsoy, Banffahira (p. 25), Presented by

the Earl of Seafield. Supporting No. 158. 168. Tazza of Cornish serpentine (p. 29J.

{We here cross la the nartlteJ'n end,)

159. Pedestal of encrinital marble from Dent, Yorkshire (p. 3]},

on plinth of granite, from Shap, Camberland fp. 27) supporting No. 160.

160. Bast of the late Professor Sedgwick, hy T. Woolner (p. 22).

Presented hy a Lady.

161. Pedestal of black marble ; Oaatleton, Isle of Man (p. 33),

with base of grey granite, from South Barrule, Isle of Man {p. 27) ; supporting No. 162.

162. Bust of the late Professor E. Forbes, bv J. C Louph

{p. 20).

163. Copy of the Dying Gladiator, in Parian cement (p. 44) ; tte

boso coloured in imitation of marlile. Ss.ft'i'Q.'. "t. Belman, the patentee.

14 The Hall.

164. Pedestal of grey granite ; Meldon, Devon (p. 26) ; sap-

porting No. 165.

165. ]m)del of an ancient cross in black slate (p. 34).

166. Pedestal of grey granite, from Gonstantine, Cornwall (p. 26) ;

with base of sonorlaceous porphyry from LnxulUan (p. 28) ; supporting No. 167.

167. Tazza of black Derbyshire marble (p. 30).

168. Large block of apatite, or phosphate of lime (p. 48), with

mica (p. 137) ; from North Burgess Mine, Perth, Ontario, Canada West. Presented by Messrs. Pickford, Winkfield, & Co.

169. Large mass of Phosphorite, containing 79 per cent, of phos-

phate of lime (p. 131), from Staffel, near Limbarg, on die Lahn. Presented by Messrs. John Taylor & Sons.

170. Lare pedestal and tazza of alabaster ; from Fauld, Stafford-

shire (p. 34). Worked by Messrs. Hall, of Derby.

171. Pedestal of grey granite ; Trewoon, Cornwall (p. 26).

172. Pedestal of grey porphyritic granite ; Lamorna Cove, Corn-

wall (p. 26) ; with base of schorlaoeons porphyry, from LuxnlHau (p. 28) ; supporting No. 173.

173. Tazza of Derbyshire rosewood marble (p. 30).

174. Mass of red oxide of copper, coated with malachite ; from

the mines of the Great Northern Copper Mining Com- pany of South Australia (p. 48). Presented by the Hon. J. Baker.

175. Large mass of native copper ; from the mine at the

Ghostcroft, MuUion, Cornwall (p. 47). Presented by the Adventurers of the Trenance mines.

176. Several portions of six-sided prisms of basalt,, from the

Giant's Causeway, Ireland (p. 47).

177. Fluted column of alabaster, from Fauld, Staffordshire

(p. 34) ; with foot of Derbyshire marble (p. 30) ; - ing No. 178.

178. Large tazza of serpentinous marble ; Ballinahinch, Galway

(p. 29).

179. Portion of a rich lead vein ; from the Grassington mines,

near Skipton, Yorkshire (p. 48). Presented by the Duke of Devonshire.

180. Pedestal of granite ; Lee Moor, near Plympton, Devon

(p. 26).

181. Pedestal of serpentine ; Lizard, Cornwall (p. 29).

182. Column of serpentinous marble ; Ballinahinch, Gttlway

(p. 29) ; supporting No. 183.

183. Tazza of coralline marble ; Matlock, Derbyshire (p. 30).

184. Column of red marble ; Cork, Ireland (p. 33).

185. Specimens of black Derbyshire marble, arranged in a colum-

nar series, to illustrate the method of turning and polish- ing (p. 30). Presented, from the Great Exhibition, 1851, by Messrs. Hall, Derby. Mounted on base of Cornish Ber- pentine.

186. Column of Clonony marble ; King's County, Ireland (p. 33).

187. Column of marble ; Michelstown, Cork (p. 33).

188. Series of specimens of Derbyshire alabaster, arranged simi-

larly to No. 185 (p. 34). Presented by Messrs. Hall, Derby. Mounted on base of Cornish serpentine.

189. Tazza of coralline marble ; Devonshire (p. 32).

190. Column of granite ; Hay Tor, Devon (p. 26) ; supporting

No. 191.

. Tazza of Oorniah. serpeatine (p, 29).

mEtrble ; Derbyebii marble liaso (p. 30). Oolumn of black Galway marble (p. 33);

HUpportlng No.

195. Obelisk of Corniah Herpontice (p. 29).

196. Pedestal of aerpantinous marble ; EhoBCol to, Angleaey (p. 29);

Bupporting No. 197. Presented by the Hoa. Owen Stanley, M.P.

197. Model in black Derbyshire marble (p. 30) of the Luxor

obeliek now erected in Paris.

198. Colnmn of miirble ; Babbacombe, Devon (p. 32) ; support-

ing No. 199.

199. Tftzza of dolomitic conglomerate ; Coity, GlamorganBhire

(p. 33] ; -with bftse of black marble.

200. Column of encrinital marble ; Matlock Bath, Derbyshire

(p. 30) ; sapporting No. 201.

201. Taazaof marble; Wetton, Staffordshire} with black marble

base (p. 31).

202. Column, of grey granite ; CragOBir, Kirkcudbrightslure

(p. 25) ; supporting No. 203.

203. TazzftofbJaokDerb;S'Bhiremarble{p. 30),

204. Colamn of porphyritic granite ; Hhap, N. Westmoreland,

(p. 27) ; fluppoilma No, 205.

205. Tozza of sheily DerliyBhire marble, with black marble base

(p. 30).

206. Column of marble ; Wetton," Staffordshire (p. 31) : support-

ing No. 207.

207. Tazza of Derbyshb-e rosewood marble, with black marble

base (p. 30).

208. Column of serpentinous marble ; Ballinahinch, Galway

(p. 29) i supporbing No. 209.

209. Amphora in Cornifih serpentine (p. 29).

210. Column of red Peteihead giwiite (p. 25.) ; supportine

No. 211.

211. Bust of Her most gracious Majesty the Queen (p. 17).

212. Column of red Peterhead granite (p. 25) ; supporting No.

213. Bust of H-R.H. the late Prince Consort (p. 17).

214. Column of marble ; One Ash, Derbyshire (p. 30) ; support-

ing No. 215.

215. Tazza in Ooruish seipontine ; a lizard, in a green variety

of the Btone, entwined around sh of red serpentine (p. 29).

216. Pedestal of grey granite; HalvaBBo, Cornwall (p. 26); sup-

porting No. 217.

217. Bust of the late G. B. Greonongh, F.E.S. By N. Bernard

(p. 19).

218. Pedestal of Berpentinoaa marble ; Ballinahiuch, Gfalway

(p. 29) i supporting No. 219.

219. Bust of the late Sir H. T. De la Beche, C.B. Bv B C

Papworth, Sen. (p. 19).

220. Column of sEi-peutine ; Lizard, Cornwall (p. 29) ; support- ing No. 221.

. Tase of Derbyshire fiir epac (p. @3} i on blwak. 'VEiaft'ldtR. pedestal.

223, Column of marble ; Bonaall, Derbyshire (p. 30) ; support- ing No. 223.

223. Vaae of Comiah eerpentine (p. 29).

224. Slab of serpentinous marble ; EhoacolTii, ARglewy (p. 29).

Presented by J. Haywood, Esq.

225. Pedestal of Coraisb serpeatine (p. 29) ; supporting ISo,.

226. Bust of Sir James Hall. By Patric Park (p. 23).

227. Pedestal of grey porphyritic granite ; CLeesewring, Corn-

wall [p. 26); supporting No. 228.

228. Buat of Profeeaor J. Playfair. By M. Noble (p. 23).

229. Column of rosewood marble ; Asbford, Derbyshire (p. 30)

supporting No. 230.

230. Tassea of black Derbyshire marble (p. 30).

231. Column of red granite ; Ross of , Argyleahire (p. 25) i

supporting No. 232.

232. Bust of tho.lato Dr. Bueklaiid, by H. Weekea, A.E-A.

(p. 24j. (At foot of western staircaae.)

In addition to the objects described in the foregoing catalogue, there will be found in this portion of the building several groups of smaller specimens which are arranged, for convenience, in a series of table-cases distributed ai'ound the Hall. Of these cases Nob. I., , II., and III., in the enstcm enibaent, contain polished cubes of ' British ornamental stones, descriptions of whicli will be fonnd under the following general headings, viz. ; Marble (p. 30] ; Gruiita (p. 24) ; Elvau (p. 28) ; and Serpeutme {p. 29), On the opposite side of the Hall, in the western embayment, are cases Noa. IV., V., YI,, and YII., containing samples of our British building stoneB. These specimens are chiefly those which were collected by the Com- missioners appointed in 1838 to select the most durable material for the construction of the Houses of Parliament. Tlie physical and chemical properties of the stones were determined Ijy the late Professors Daniell and Wheatstone, the other members of the Com- mission being Sir Charles Barry, Sir Henry Do la Beche, Mr. "Wil- liam Smith, and Mr. Charles H. Smith. The specimens snbmitted to the Commissioners, and on which they reported (Beporf of Building Slone Gomruiaeiun, \hth July 1839], were, by the order of the Ijords of the Treasury, placed in this Museum, and the ccdleo- tion has since been augmented, partly by private donations and , partly by contributions from the Geological Survey. For a desorip> tion of the Sandstones, see p. 36 ; of the Limestones, p. 37 ; of the Dolomites, p. 39 ; and of the Granites and Elvans, p. 24.

Case VIII., on the western side, near the statue of the Apollo Belvedere, is devoted to examples of hard stones used for the purposes of grinding and polishing (p. 40). Ou the eastern side, near the large alabaster tazza, stands Case IX., containing aix interesting collection, intended to illustrate the preparation and uses of plaster of Paris (p, 43), whilst the adjacent case, No. X., is occupied by samples of crucibles and melting pots, noticed at p. 46.

The wall-space on the eastern aide of the Hall is decorated viih British omameutal atones, commencing with a screen estendinsr from the southern end to pilaster No. 36. In this screen, whi is from the design of Mr. Charles P. Keeks, architect, the cenb panels are of Ballinahinch serpentinous marble, suiTounded by grey Derbyshire marble, with rouning borders of gnilloche and fretwork, the former of red StaBbrdshire marble and Derbyshire anhydrite, the latter of similar red marble and Derbyshire btalagmite. The

pilasters and architrave are of Lizard Beipentine, whilst tiie base ia of rusaet and bird'a-eye marble from Derbyshire.

The Bcreen between pilMtera Noa. 36 and 43 exhibits a large central panel of marble from the Mumbles, Swansea, with smaller panels of Ipplepen marble, Deyon ; while the coniice ia of Lizard serpentine, ajid the remainder of Derbyshire marhlea.

la the space between pilasters Nos, 43 and 44 the circular centre ia of Derbjahire rosewood marble, and the remaining panels of encrinital, coralline, and other varieties of Derbyshire marble, whilst the gronnd in which the whole is inlaid is of Fauld alabaster, and the baae of reddish syenitic granite from HoiMit Sorrel, Loicea- toTKhire (p. 27).

Scotch granites and marblea occupy tho wall-space between pilastera Hos. 44 and 48. On the base of grey granite from Kenmay (Aberdeenshire) rests a moulding of red Corrennie granite, aboro which is a dado of grey granite from Caimgall, near Peterhead, surmounted hy a cornice of pink granite from the tale of Mull. In tho upper part the gronnd ia of red- granite from the Stirling hill

Saarriea, near Peterhead, whilst the central circular pane! ia of trathdon marble (Aberdeenshire), and on each side of this ia a panel of bornbleudic porpSijry from Mayon, near Hnntly, Aberdeenshire. Tho rom.aining panels, which in most cases correspond on opposite aides, are, commencing from below, of Kinsweli porphyry (Aber- deenshire) ; Glen Tilt marble (Perthshire) j Sntherlandshire marble on the left hand, and Portsoy aerpentine on the right ; Tiree marble, Hebrides and Enbislaw granite, Aberdeenshire.

The tesaelated pavement in the centre of the Hall (p, 46) ia surrounded hy alaba of grey Aberdeen granite, and these again by slabs of red Peterhead granite, the whole being bordered by a guilloche in Minton's encaustic tiles, formed of compressed coloured clays. Similar tiles form a pavement at the top of tho steps leading from the vestibule, and again on the north of the tesselated pave- ment around the statue of Hercules. Theremaindorof the pavement ia of Portland stone (p. 88), aa also are the columns BupjKjrting the

While examining the contents of the Hall it should be borne in mind that the object of this section of tho Museum is almost purely technological, its main purpose being the illustration of the applica- bility of the rocks of the United Kingdom to purposes of architecture and ornament. Hence the geological student who wishes to study the physical characters of our rocka rather than their indnstrial uses must be referred to the series of British rock specimens in the upper gallery and to the mineral collection on the principal floor, detailed catalogues of both of which have been published,

BUSTS. Hee most GKiCJOus Majesty tiib Queek. Stcttted hij Francis, 1850. No. 211. H K H TEE LAiB PHrsCE CossouT. Eacxtl d by Frayids, 1843. Wo. 213. The being cast in zinc, arc subsequently hroaaed, and are examples of the application of an inespiinsive material in the pro- duction of works of art

Tho busts of eminent men who have advanced tho science of

Geology form appropriate and interesting features in. tti\a"BssS. ""s

J

18 The Hall.

notices are introduced. The are described in the order in whicli they will be most readily fonud by the visitor, who on entrance tarns to the right and proceeds around the tesselated pavement in the central area.

Sir Roderick I. MrRCiiisox, Bart., K.O.B. — An origmal bust hj H. Weelces, R,A., 1871. BequeaHied by Sir B. I. MurchUon. No. 2.

Sir Eoderick Impey Murciiison, who succeeded Sir Henry De b Bccho as Director of this Institution, was bom at Torraoale, in Ross-shire, on February 19, 1792. Intended for the army, he was educated at the Royal Military College at Great Marlow, and in 1807 he obtained a commission in the 36th Foot. During his militanr life ho saw active service in the Peninsula, and was present at the battle of Vimieria and the retreat on Corunna. On the con- clusion of the war ho married the daughter of General Hugonin, and soon aftenvards quitted the army, though it was not untU 10 yeais later that his attention was turned, by Sir Humphrey Davy's in- fluence, to scientific pursuits. His first practical lessons in geology were received from Dr. Buckland, whose enthusiasm incited Mur- chison to enter the field as an original obser\'er, and thus determined his future career. In 1825 he contributed his first paper to the Geological Society, of which he was henceforth one or the most

Erominent members. Murchison's great work, the work with wMch is name will always be identified, was that of determining the succession of the older rocks, which had previously received but little attention from geological observers. This task he commenced in 1831 by working on the old rocks of Wales in conjunction with Professor Sedgwick, the two proceeding, however, from different base-lines. Sedgwick's labours lay among the disturbed. rocks of North Wales, where he established his Cambrian System;" Mur- chison's among the rocks of South Wales, where he laid the founda- tion of his Silurian System.'* The famous work bearing aa its title " The Silurian System " was published in 1836. Soon firffcer- wai'ds Murchison's attention was turned to the geology of Russia, and in 1840 he visited a part of the empire in company with the French geologist, M. De Verneuil. The following year he returned and made a more extended survey, aided by Count Keyserling, and encouraged by the Emperor Nicholas, but it was not until 1854 that he published his fine work, the Geology of Russia and the Ural Mountains." In the same year he brought out, under the title of Siluida," a large volume giviug a general description of the older rocks, or a summary of palaeozoic geology.

At an early period of Murchison's geological career he had shown, in conjunction with Sedgwick, that the slaty rocks of Devonshire are approximately of the same ago as the red sandstones of Hereford- shire, and thus established the Devonian System." The formation of the " Permian System " was suggested at a later date by his travels through the old kingdom of Perm, in Russia, where he found a large development of rocks of this geological age. In 1846 Mr. Murohison received the honour of knighthood, and on Sir H. De la Beche's death, in 1855, he was appointed Director of this Museum and of the Geological Survey of the United Kingdom. He was one of the original founders of the British Association, and presided over its meeting at Southampton in 1846. Geographical science shared his attention with geology, and from 1844 to the time of his death he was almost perpetual President of the Royal Geographical Society. Through his influence a chair of Geology and Mineralogy, was eete-

Busts. 19

IjliBhed in the TJniTersity of Edinburgh in 1871, and towards the endowment of thia chair he oontribnted 6,000J. The " Mnrohiaon ProfesBorahip," 88 he wished it to be oalled, is held by his biographer, Mr. Archibald G-eikie, Director of the Geological Survey of Seotland. Sir Eoderick died on October 23, 1871, and whb ancceeded Ire Pro- fessor A. 0. EamBay aa Direa tor-General of the Geologioal Survey and of the Musenm of Practical Geology.

Geoboe Bellas Geeenovgh, P.R.S. — An oiigviial lust by Neville B-wi-nai-d, 1859, jii'esBjiieo! bi/ Iho lata Mks E. if. Sirtedhi;. No. 217. Georgb BELtis Greenougii, the fonnder of the Geological Society, was bom in 1778, and died at Naples in 1855. Intending to foUow the legal profoasion, Mr. Greenongh, after atjidying at Cambridge, proceeded to the University of Guttingon, where the attractions of Blumenbach'a lectures on natural history Induced him to abandon the law, and devote hia enorgiea to the pursuit of natural science. With this view' he subsequently studied at the mining achool of Freiberg, under the distingTuahed Werner, whose views he warmly espoused during the unhapijy contrQveray between the Nejituniata and Vnlcaniata, In the iannation of the Geological Society of London, Mr. Greenongh took a most active pact, and in apite of the opposition offered by the Boyal Society, hia esertiona were rewarded by ita complete organization. Aa an appropriate honour to one who bad steadfastly supported its foundation, Greenongh was elected the first president, a position which he continued to hold for several years.

Although poaaeBsing rich storea of information, aocumnlatod during a lon§ and Jealous life, Mr. Greenough waa not a, great writer ; but his profound acquaintance with the aciencea of geology and geography is aufflciently attested by hia valuable geological maps of England and Wales, and of India; the former published in 1819, and the latter in 1854, only one year before hia death.

Sm Henbt Thomas Db la Beche, C.B.— By E. 0. Fapviorth, from a. bust hy E. H. Bally, B.A. No. 219.

This eminent geologiat, the founder of this institution, 'was born, in 1796. Having lost bis father at an early age, ho resided for some years with hia mother in Devonshire, then at Charmouth, and afberwarda at Lyme Eegia. To hia early asBOciationa may be re- ferred those studies which becajne tbe business of hia life; and it ia intereating to witness the love with which he always returned to the oonaideration of the rocka of Western England, amongst which in his boyhood he had rambled ; always finding, never seeking, pleasai-e. In 1810 Henry de !a Beche entered the Militaiy School at Great Marlow ; but he never embraced the profession of arms, and in 1817, entering the Geological Society, he enrolled himself in that select band, who were then struggling to eatablish geology as a science, and of which he soon became a guiding spirit, find eventually the leader. Mr. De la Beche always exhibited great activity of mind, and numerous memoira and other publications were continually proceeding from his pen.

In 1835 waa commenced the great work of the Geological Survey of the United Kingdom, which may be regarded aa one of the fiat scientific inquiriea fairly recognized by the Government of this country. Mr. De la Beche was attached to the Ordnance Survey, with power to carry out a geological anive cS Ita -weaKini. aaa.-o.- tiea, and to publish hia reaalta on tlie onft-mob. Ot&ooatfe tok?.,'V3

20 The Hall.

geological colouring. Upon this important point the words of hia snccessor, Sir Roderick I. Murchison, spoken on receiving from the Geological Society the WoUaston medal for his friend, then in his last ilhiess, are especially to the purpose :

''At his own expense he traced the boundaries and relations of certain rock formations, and laying them down on the Ordnance Survey maps, accompanied hj illustrative sections, he thus took the first step in leading public men (otherwise little versed in our science) to see the good which must result from the extensive ap- plication of such a scheme, in making all proprietors alive to the importance of obtaining a better acquaintance with the subsoil of their estates.

Having gradually attracted the notice of the Government, and having obtained the use of rooms in Craig's Court, and the em- ployment of a limited sum of the public money. Sir H. de la Beche then attached to his new-formed establishment able men of science, who could decipher formations in the field, describe the fossils they contained, or chemically analyse the structure of the rocks and their associated minerals. Soon filling to repletion the small space allotted to him with models of mines, illustrative drawings, and specimens of fossils, ores, and building stones, he convinced our rulers, and particularly the illustrious statesman Sir Robert Peel, that the dignity and interests of the country required an adequate and appropriate building should be erected, and exclu- sively devoted to the fulfilment of a project so lucidly devised, and thus far so well realized: Then arose very much after the design of the accomplished -director himself, that well adapted edifice inJermyn Street, which to the imperisliahle credit of its author, stands forth as the first palace ever raised from the ground in Great Britain hy the Oovern- rhent, tohich is entirely devoted to the advaiicement of science.

*'Once possessed of halls worthy of so noble an object. Sir Henry De la Beche next rendered them practically useful to the public, and on a vastly extended scale, by embracing, as necessary adjuncts, metallurgy and mechanical science, in addition to the branches of knowledge previously cultivated."

For his zealous labours in the cause of geological science, the Director-General of the Geological Survey was knighted by his sovereign. On the continent, too, the labours of Sir Henry De la Beche were fully appreciated ; he was created a knight commander of the Danish order of Danebrog, and of the Belgian order of Leopold ; he was elected a corresponding member of the Institute of France, and member of various foreign Academies.

On the 13th of April 1855 Sir Henry Thomas De la Beche died; his mental energies remained unimpaired to the last. Thirty-six hours before his decease he visited the Museum, and spent upwards of an hour in carefully examining the results of a statistical in- quiry into the coal and iron produce of this country by the author of this Guide. This was the last public labour which engaged the attention of that mind, of which the Geological Survey and the Museum of Practical Geologv remain enduring monuments.

Another bust of Sir H. T. De la Beche, in bronze, presented by Mr. E. H. Baily, E.A., is placed in the Library of the Insti- tution.

Pkofessob Edwaio) Forbes. — An original hmt hy L C, Lough, 1856.

Presented hy subscription, No. 162.

Edward Forbes was Palaeontologist to the Geological Survey of the United Kingdom, and lecturer on. Natural History in the

GoTemment School of Miiiea. He Tvas bora in the lale of in

Edward Forhee was a natumliBt from his childhood, alwaye delighting in the worka of creation spread around him. He epeiit Bome time at the University of Edinburgh, and in 1833 he travelled with a fellow student to Norway. Eight years after thia he wbb appointed Naturalist to a Burveying expedition, to the Mediter- ranean. With Captain Graves, iu H.M.a. "Beacon," he proceeded to the scene which he has marked by his important lahourB. In the .3;gean he was enable to determine some remarkable facta connected with animal life in the ocean, and to carry out those dredging explorations which enabled him subsequently to deduce some important conei derations on the distribution of animal life in space and time. During this appointment he travolled in Lycia, and fised the sitea of several of the Cibyratic cities. In 1843 Edward Porbes was appointed Professor of Botany in King's College. He shortly after became Secretary and Curator of the Geo- logical Society, Palfeontologist to the Geological Snrvey, and on the the organization of the Government Sehtiol of Mines, its Pro- fessor of Natural History. To the Memoirs of the Geological Survey Professor E. Forbes contributed several valuable papers ; and under his care was commenced the publication of the Decades, iUuBtratlra of British organic remains.

On the death of ProfeBSor Jameson, the Begins Professor of Natuml History in the Univereity of Edinburgh, Edward Porhea w((8 appointed to succeed him. This chair ivaB the object of Forbes's ambition, tut he was not destined long to enjoy it ; ho died on the 18th November 1854, only six months afler his appoint-

ProfesBor Edward Forbes's latest work, of which he left an fiut- Hne sketch at the time of his death, ' ' On the Tertiary Flaw-Marme Fortnati'mof the Isle of WiM," was completed by hia oolleaguea, and published aa one of the Memoirs of the Geological Survey.

ProfeBsor Forbes woa succeeded in the chair of Natural History

Pkofessoe J. B. Jtixeb. — Cast from an oriymal lust liy Joseph Watkins. No. 64. J. Beete Jukes wae one of themany Cambridge menwho acquired an enthusiastic taste for geology from the spirited lectnrea of Professor Sedgwick. Mr. Jukes entered St. John's College in 1830, having received his previous education at the Merchant Taylors' School in Wolverhampton, and at King Edward's School at Bir- mingham. Anxious to make geology his profession, he accepted in 1839 an appointment in Newfoundland, and devoted two years to the exploration of the island. In 1842 he published the resnlta of bis investigations in a work entitled " Excuraiona in Newfound- land." Soon after his return to England he was appointed natnraJiat to H.M.S. "Fly." The special object of the voyage which he then undsi-took, under Captam Blackwood, waa to survey the great series of coral reefs which form a harrier rnnning along the eastern coast of Australia for upwards of a thousand miles in length. The narrative of this expedition was admirably written by Mr. Jukes. He had not been long homo from this voyage before he received an appointment on the staff of the Geological Survey, vsitli. which ho remained connected during tte teat Via work as a Govcjianent BUirej'or lay among \.Ve -aVi -to'iV'a o'i.

The Hall.

Wales and the coal-measures of Staffordshire. A valuable memoir by Mr. Jukes on the Geology of the South Staffordshire coal-field was published in 1853. When Professor Oldham left Dablin to take the superintendence of the Indian Survey, Mr. Jnkes wafl appointed liirector of the Irish branch of the Geological Survey. He was also Lecturer on Geology at the Eoyal College of Science in Dublin, and the author of some excellent educational works oe llogy. Mr. Jukes died on August 1st, 1869, and was sacceeded in his official appointment by Mr. E. Hull.

William Smith, LL.D. — An original lust hy M. Noble. IN'o. 69.

William Smith was the author of the first geological map of Eng- land and Wales. He was bom 23rd March 1769 at Churchill m Oxfordshire, and died 28th August 1839 at Northampton. At an early period, being employed to make careful surveys of collieries in Somersetshire, ho was much struck with the constancy of tbe order of superposition of the strata ; and this appears to nave led him to a general examination of the country. In 1794 Mr. Smith was enabled, by one long journey through great part of England and Wales, to commence his Geological Map of England and Wales," and to draw up a "Table of the Superposition of the Strata." It was not until 1815 that those labours were fully de- veloped, when he published a Delineation of the Strata of England and Wales," and a memoir on the subject. In 1831 the G-eological Society of London awarded to Mr. W. Smith their Wollaston medal in consideration of his being a great original discoverer in English geology, and especially for being the first in this country to dis- cover and to teach the identification of strata, and to determine their succession by means of the imbedded fossils."

James Hutton, M.D. — An orig inal hist hy Tatric TarJc, No. 76.

James Htjtton was bom 3rd June 1726 at Edinburgh, which University he entered as a student in 1740. Dr. Hutton devoted much attention to agriculture; and when seeking information on rural economy he appears first to have acquired a taste for mineralogy, and, as he himself expresses it, became remarkably fond of studying the surface of the earth."

In 1777 Dr. Hutton gave to the "world his first publication, " Considerations on the Nature, Quality, and Distinctions of Coal and Culm." During thirty years Dr. Hutton's attention was tamed to geology, and this led him to communicate to the Royal Society of Edinburgh his " Theory of the Earth," that most remarkable and original work, which was in truth the foundation of modern geology. This was subsequently published in two volumes. Dr. Hutton died in 1797, and of him it is said: — "The greatest acquisitions of wealth and fortune never excited more lively sensations of pleasure in the minds of men than those which arose in the mind of Dr. Hutton on hearing of a new invention, or on being made acquaLoted with a ne truth." He would rejoice over Watts' improvements on the steam engine, or Cook's discoveries in the South Sea, witib all the warmth of a man who was to share in the honour or the profit about to accrue from them."

Pkoeessor Sedgwick, LL.D., F.R.S. — B&pliqua of original huat hy T. Woolner, Fres&nted hy a Lady. No. 160.

Adam Sedgwick, Professor of Geology at Cambridge for more than half a century, was the son of the vicax oi"!Deii\, tjiW tAFm

f , BUSTS. 23

in the noi'th-weaternpart of Yorkshire, where hewaa born onilarch 2d, 1785. He received hia edncation first at Sedhurgh School, and afterwurda at TriuiCy College, Oamhridge. Having distin- guiaiied himBelf as a high wrangler, he waa ajointed, in 1818, to the WciJdwardian Professorship in Buceeasion to Profes hot Hail stone. It ia the function of the Woodwardian Professor to defend the views held fay the founder of the chair as to the nature and origin of foBsilB, bnt previously to Sedgwick's appointment no ayatematio lectui'ea on geology had heen delivered. On receiving the appoint- ment, however, Sedgwick applied himself with characteriatio cai'nestnesH to the study of the science which was thaa thrust upon him, and witlt sach suooess tb&t he waa enabled, in 1820, to puhlisb. the results of some original ohservationa on the physical strncture of Devon and Cornwall. During tlie remainder of his days he devoted iimaelf to the science which he thus took up, and continued B.3 long as strength permitted to spend his leiBnre time in original field-work. By nis researches among the old rocks of Cumberland and North Wales he waa enabled to establish his " Cambriaii Sj'stera." As a lecturer he exerted peculiar influence, and many of Lib pupils, fascinated by hia enthusiasm, have become geologists of the first rank. In 1833 Sedgwick presided over the meeting of the British Aasooiation at Cambridge, and the following year he was made a canon of Norwich Cattedi'al. The Woodwardiau Musenm aa Cambridge waa founded by Sedgwick in 1842, and to such an extent has this magnificent collection of organic remains since grown that: new bnildinga are about to be erected for ita acoommodatioii. Professor Sedgwick died on January 27th, 1873, and was succeeded by Mr. T. McK. Hughes, formerly of the Geological Survey.

Sm James Hall. — An original Irast hj Patric Fork. Ho. 236.

James HtLt, — There were few men who united with more advan- ti8go chemistry and geology than Sir James Hall. At the period when the theories of the earth's formation were sealonsly diseusaed. Sir James Hall was induced to make some experimenta of a very important character in connexion, with the sabject.

The results of these investigation a ivil! be found in the Trans- actions of the Eoyal Society of Ediaburgh. Sir James Hall died in 1832 ; wid as an attentive geological observer, and a aealoua ohemioal experimentalist, hia bust finds its appropriate place with the men of his time, Playfair and Huttoa.

PuorEssoB Z. 7Li.jiim.—A/'er Sir F. Chantry hy-M. Noble. No. 228. John Playfaik was bom at Beuvie, in Forfarshire, March 10, 1748. Dr. Wilkie, the Professor of Natural Philosophy at St. Andrews, finding himself unabl& to discharge the duties of hia office, delegated them to Playfair, then a etndent ; this fact provea t.he estimation in which he was then held. In 1773 Playfajr ob- tained the living of Liff and Benvie, and in 1779 he communicated his first paper to the Boyal Sociefj of London. In 1785 he waa appointed Professor of Mathematics, jointly with Dr, Ferguson, in tho TJnivei-sity of Edinburgh ; and on the death of Mr. Bobinson in 1805 he succeeded him to the chair of Natural Philosophy in that university. Ho was the intimate friend of Hutton and the Btrennons supporter of the geological theory which bears that philosopher's name. Playfair's " Illustrationa of the Hutsoniao. Theory of the Earth " have been much. BAv(ure4 tot Tai c\OTCM*.'fi*. with which tic system was unfolded, Hia wQiVa -Ntv ci'i tO'-'*'

24 The Hall.

cellaneous character, chiefly connected with mathematics and the higher branches of natural philosophy. The death of Professor John Playfair took place at Edinburgh on the 19th July 1819.

William Buckland, D.D., F.R.S. — A htuthyH. WeeJces, 1860. Presented by svbecription. iTo. 232.

William Buckland was bom at Axminster on the 12lh March 1784. His taste for geological pursuits appears to have been dere- loped at an early age, for we find him when a youth at Winchester College occupied in collectiDg the chalk fossils of the neighbour- hood, and on his subsequent removal to the University of Oxford the fosBils of the oolites enabled him to pursue his favourite em- ployment. At Oxford he attended the mineralogical lectures of Dr. Kidd, and on that gentleman's resignation in 1813 Buckland was appoiuted to the vacancy. About this time the importance of geological science began to be recognised at the university, and in 1818 a special readership in geology was founded, to which Dr. Buckland was advanced. His inaugural address on this occasion was afterwards published under the title of Vindiciae Geologic, or the Connexion of Religion with Geology explained.** A few years later he gave to the world the interesting results of his original researches on bone caverns, in the form of a valuable treatise, entitled '*Reliquia3 DiluviansB, or Observations on the Organic Remains in Caves, &c., attesting the action of an universal Deluge." Some of the views there maintained he was subse- quently induced to modify, as seen in his later work, the admirable Bridgewater treatise on Geology and Mineralogy considered with reference to Natural Theology." Dr. Buckland's zeal as a practical geologist and his ability as a writer are seen not only in these larger works, but also in the number of valuable papers which he was constantly contributing to the* Geological Society. Towards the close of life, however, his mental activity declined, and after several years of retirement from geological pursuits he expired on the 14th August 1856, having been Dean of Westminster for eleven years.

Gbanitb.

In its typical varieties granite consists of a crystallo-granular mixture of the three minerals, felspar (p. 136), qua/rtz (p. 131), and mica (p. 137). The felspar, which usually forms the chief con- stituent, is in most cases the common potash-felspar called oriiO' clase ; but this is frequently associated with a soda-bearing species which is commonly oligoclase, but in some cases appears to be albite (p. 136). The orthoclastic felspar often occurs in large well-formed crystals embedded in a fine-grained base, thus producing the beau- tiful porphyritic granites, of which some fine examples are exhibited (p. 27).

Certain varieties of granite rapidly suffer disintegration, while others are remarkable for their extreme durability. Combined with a considerable degree of hardness, this durability renders granite highly valuable as a building stone for bridges and other massive structures, while the toughness of the homblendic varieties makes them especially suitable for road materials. At the same time the beauty of many granites, and the high polish which their hardness renders them capable of receiving, recommend their use for pur- poses of ornament. The industrial applications of granite are, how- ever, greatly restricted by its expense.

Gbaiotes. 25

Gbakites of ScoitiKT. — steps at Enti'anee. Pi7n*feiw on each side

of Btairg /mil Ball, and No. 36 and 125.— Screen i.— Slabs

BTirTowidwi ieesdated pavement — Fedeelah, Cohemns, Sfc, Nos. 9,

84, 94, 111, 112, 119, 152, 153, 157, 202, 210, 212, and 231,

Ciibee Ml Talk Cases IIJ. and TIL

Tho granite of Aberdeen, especially that from the qnarrieB of

Dancing -Caira, Kubialaw, and Tjrebagger, is much used in the

metropoliB for kerb and paying etones j the nanal colour is grey,

l)ut BomB red granite is also quarried. Axonnd Peterhead the red

granite prevails, hence it ie usually difitingniitbed as the Felef-

liead granite, 'the principal quairjea are those of Black Hill,

four miles west of Peterhead, belonging to the Governors of the

Merchant Maiden Hospital of Edinhnrgh, those on the estates of

the Earl of Errol, at Boddam, at Longbaven, at Oaimgall, oad at

Eova. Tho Sheerncsa Docks were built mostly with stone fVom

these quarries. The Stirling Hill quarries, at Boddara, furnished

- the pillar of the Duke of York's monument, the Seafield quarries

the abacas. The beautiful pillara in the library of the Britiah

Museum were obtained from Longhaven ; tho cost for transport at

the time the; were worked being something almost fabulous, so

freat were tha diffioultiee attending their removal. The pillara in ishnumgers' Hall are from the Stirling quarries, as are also the bases of ftio monuments of Pitt and Fox ; while the polished pillars of the Carlton Honse are from the quarries near Peterhead.

The fine pink and red granites of the Isle of Mali have been largely worked by the Scottish Granite Company, and were employed in the erection of the Albert Memorial in Hyde Park. SpecimenB of Scotch granites are exhibited from the following localities ; — Peterhead, Aberdeen, and Corrennio HUl, Aberdeenshire ; Portsoy, Banffshire; Dalmore, Sutherland; Oban and Mull, Argyllshire; Tirec, Hebrides ; and Craignair, Kirkcudbrightshire,

Tho granitic rocks of Ireland occur in fonr districts, namely : — in Donegal, on the northTwest ; in Galway and Mayo, on the west ; in "Wicklow and Wexford, on the south-eaat ; and in Down and Armagh, on the north-east. {Hull's Building amd Ornamental Stones, 1872.)

The most extensive granite district in Ireland, and indeed in tho whole of the Britiah Islands, stretches south fi-om Dnblin, through the counties of Wicklow and Carlow into Kilkenny and Wexford, occupying an area 70miles in length, and from? to 17 miles in width. The granite of the Wicklow range is the moat extensively used. It varies in its quality, that near Kingstown being coarse and hard, while that from Balljknockin or Golden HUl is much finer, and therefore fitted for ornamental work.

Killiney Hill, near Dublin, has yielded enormous quantities for the harbour and pier of Kingstown, and for numerous buildings in and aronnd Dublin. It baa also been employed in the Thames Em- bankment.

In Galway at least two varieties of granite have been recognized, bat the characteristic Galway granite is a handaome porphyritic rock with large crystals of red orthoclnae. This rock has been quarried at Fiu'bogh, eight miles from Gnlway, and a column (No,l.\ showing tho appearance of tho granite heu oYisVei -Wi.\)ft tisrai in the Hall.

26 The Hall.

Passing to the north-east of Ireland we. find granitic rocks form- ing three distinct tracts in the mountain ranges of Moume, of Ca lingford, and of Slieve Croob. It is the last only which is laj*gely worked.

The granitfe of Newry is extensively quarried, and sent by water to the north of Ireland, whilst a quarry at Castlewellan has yielded much of the granite used for the base and pedestal of the Albert Memorial.

The following localities are represented in the collection : — Eings- town, Killiney, Dalkey, Kilgobbin, and GlancuUen, co. Dablm; Glenaroe and Bally knockin, co. Wicklow; Ballyholland, near Nowry, co. Down ; and Galway.

Granites of Cornwall and Devonshire. — FedestaU and Colum No8. 3, 10, 134, 148, 150, 164, 166, 171, 172, 180, 190, 192, 216, anvd 227. Cubes in Cases III. and VL

By reference to the Map of the Geological Survey the granite districts of western England — coloured pink — will be seen, appear- ing as five islands of granite rising out of the surrounding killas or <?lay slate ; and around these are a few smaller outlying masses.

The more important quarries from which this durable stone is obtained are those of Lamoma, to the west of Penzance; the Penryn quarries ; the quarries near St. Austell ; Hensborough, near Lostwithiel ; the Cheesewring, near Liskeard ; Gunnis Lake, near Calstock ; the Delank quarries near Padstow ; and the Dart- moor quarries in Devonshire.

The following is from the pen of Sir Henry De la Beche (Beport' on the Geology of Devon , Cornwall, and West Somerset),

There is much good granite on Dartmoor, though it is not always suflSciently accessible to be carried long distances ; the chief places where it is worked in largo quantities and afterwards exported are, Hey or High Tor on the east, and near King Tor on the west. The granite from the former place is conveyed by a tramroad to the Stover canal, down which it is carried in boats, and afterwards down the Teign to Teignmouth, to be shipped for its destination. That from the west side of the moor is conveyed by the Prince's Town and Plymouth tramroad to the latter place and shipped.

The continuation of the Hingston Down granite is worked up the Tamar near New Bridge and exported from Morwellham. A very hard variety is obtained upon the higher part of the Down, and has been employed advantageously for pavements. ♦ The chief quarries in the eastern or hard part of the Hensborough mass of granite are those of (the late) Mr. Austin Treffry, up the Par Valley, conamonly known as Lostwithiel granite. Extensive quarries are there , wonted, and the stone is brought to the head of the canal near Pons-miU, upon which it is conveyed to Par harbour, and there shipped. The Carn Menelez mass has fur- nished the granite most commonly known as Cornish. It is nearly altogether shipped at Penryn, where it is brought variable distances from different quarries in the vicinity, many situated in the parish

Since the above report was written the quarries on the eastern edge of Dartmoor have ceased working ; those at the Cheesewring near Liskeard have been opened, and stone of a beautiful quality is raised and exported in large quantities from Looe. The Lamoma

Suarries to the west of Penzance and a -large quarry, Mill Hill, in [adron, have algo been worked. The stone obtained from those

GIUHTTBeS &c. 27

(quarries is of excellent quality, and it can bo obtained of very large

The following great workg, amongat many otliera, have bean conatrnctod entirely or in part of Comiab granites : The Penryn and Lamoma granites have Bnpplied Portland breakwater ; Keyham Docks for the Steam Navy ; Commercial Ifocka, London ; the Httle, Great WeBtem, and Birkenhead DoekB, and the ITationftl "Works at Ohatham and Portsmouth, together -with the Scntari monument. The pUntb for the railings of the British Mnaonm is from the Camaew

g Harries, and the towers, including the lodge for gates, &c., from onetantine. The Constantino granito has been nsed for the Wel- lington. Memorial at Stratlifieldsajc, the shaft of the column being 30 feet in height in one atone.

, The Cheesewring granito has been nsed in the London Docks, "Westminster Bridge, the Thames Embankment, Rochester Bridge, tbo docks at Copenhagen, the Great Basses Lighthouse nea,r the island of Oejlon, and for the tomb of the Duke of "Wellington in the orjpt of St. Paul's Cathedral. These qnarriea prodace from 8,000 to 10,000 tons of stone per annum, and about a similar quantity is annually shipped from the qnarriea near Par.

Cornish gnuutes are exhibited from the following localities : — Lamorna Cove, Paul, Caatle-an-Dinas, Maraaion, Madron, Lndgvan, Constantino, Camsew, Mabe, Penrju, St. Austell, St. Blazey, Lanlivery, Luxnllian, Eoacii, Lanivet, "Withiel, Bodmin, Oaatle Quarry, St. Breward, Cardynham, St. Neots, Trewoon, Trowles- worthy, Halvasso, and the Cheesewring.

Devonshire granites are exhibited from the Fremator quarries near Tavistock, and from Blackoastone and Heytor, Dartmoor.

In addition to the granites from our western counties noticed above, a few other apeoimene are exhibited from localities of much

less importance. Shwpfell, in "Westmoreland, furnishes a beautiful porphyritio granite represented by the Column No. 204, and by tho plinth of the pedestal which supports Hie bust of Prof. Sedgwick. The Shop granite is now workea, and for tbia purpose a company has erected cutting and polishing machinery by the side of the Lancaster and Carlisle Railway, nearflhap Station. Mount Sorral, near Chamwood Forest in Leicestershire, yields a pink syeuitio granite, which has been employed in the decoration of the eastern waU. The base of the pedestal H"o. 161 is from the boss of granite which penetrates the surrounding schists on the aonth-eastei'n aide of South Bamde, one of the highest points in the IhIb of Man. The gramte of Lundy Island is represented by several cubes in Oases HI. and Til. As these specimens were all obtained from near the exposed surface they anffloiontly attest the durability of the stone, but probably much bettervarieties would be found at greater depths. From the Chatinel Islands large quantities of granito are exported, chiefly for ubo as London road-metal. Specimens are exhibited in the table-oases from the quarries of Mount Mado and La Perruque in Jersey, and from Guernsey and its dependency, the little islimd of Herm.

PosPETEiES. Elvans. SiEsrtEs. Greenstone.— Co iMmiis, Slabs, Sfc.

Nos. 1. 95, 133, 134, 135, 136, 150, ISi. 166, 172, 192, and 204.

Oases III., ril.

Under the generic term Porpl'ijrij wo grouped all those varieties

of rocks that consist of a matrix in which distincA- ciytft *'™'g

bedded; the term thus re fern ng i-amber to ftio -"baXc/cX

28 The Hall.

the rock tlian to any more essential character, and hence embracing many yarieties which in chemical composition are widely distinct. TVue porphyry consists of crystals of felspar in a felspathic base: the type of this rock being the ancient red porphyry of Egypt Many of the Cornish and Devon granites in the collection are eminently porphyritic, and we may especially notice the pedestid and columns Isos. 172 and 192 on the eastern side and Nob. 150 and 154 on the western side ; the latter two, from Tianlivery and - lian in Cornwall, have been employed, especially by the late Ikfr. Austin Treffry, for ornamental purposes. The sarcophagas for the late Duke of Wellington, now in St. Paul's, is formed of one huge mass, of the same character as the red and black variety in the column, No. 154, and in the bases of the pedestals Nos. 166 and 172. This beautiful rock, which, from its locality, has been called Lvand-' lianite, consists of large crystals of pink orthoclase-felspar, associated with much schorl, or black tourmaline, and a small quantity oT quartz.

Upon reference to a good Geological Map of Cornwall a number of bands will be seen traversing both the granite and slate rocks of Cornwall, having a main general direction from the north of east to the south of west. These represent dykes of what is locally termed Elvan, a rock closely allied to gramte, from which indeed it principally differs in the general absence of mica. Frequently the elvans become porphyritic, being chiefly composed of a felspathic or a quartzo-felspathic base, containing crystals of felspar and quartz, sometimes schorl, and occasionally, though rarely, mica.

Sir Henry De la Beche remarks of the Cornish elvans, "For durable stone the harder elvans of this district, particularly when of good cream and other light colours, may be considered as the best building materials in it : their durability and appearance may be seen in many churches and old mansions, where the finer carvings of the ornamental parts are as sharp as the day they were put up. Occasionally the felspar crystals may have been decomposed and have been washed out, but the siliceo-felspathic base has remained firm, thus preserving the sharp character of the work." The Cornish elvans have been recently described before the Boyal Corn- wall Polytechnic Society by Mr. A. K. Bamett; and* much useful information upon the building and ornamental stones of Devonshire and Cornwall in general will be found in The Report on the Oeology of Cornwall, Devon, and West Somerset, by Sir Henry T. De la Beche.

In the Table Cases III. and YII. will be found specimens of elvans from Mayen, Land's End; Marazion, near Penzance; Breague, near Helston ; Porkellis, Wendron ; Eoscrow and Tre- vailes, Penryn ; Newhaven, Truro ; near Newquay ; Pentuan, and Dowgas Mine, St. Austell ; Withiel, Lanivet, St. Neots, and Tre- more, near Bodmin ; St. Dennis ; Camelford ; and Meldon, Oke- hampton, Devon.

Granites frequently contain various accessory minerals, of which one of the most common is the lustrous mineral hornblende. This sometimes occurs to the entire exclusion of the mica, and the rock thus formed, consisting essentially of an aggregate of felspar, quartz, and hornblende,, is commonly termed Syenite, a name derived from the ancient quarries of Syene in Upper Egypt, whence a homblendio granite was formerly obtained. Several examples of syenitic granites will be found in the collection amongst the Guernsey and Irish specimens. It should be observed that many petrologists restrict the term syenite to a rook composed only of

orthoclase and qnaitz. When the rock conaiHts of felspar and qiiajtz, bat the felapar is oligoclase iaetead of orthoclaBe, it gene- rally passes under the name of Greenatone or Diorile, ofwbich an ex- ample from Llanwnda, in Pembrokeahira, will be seen in the copy of a. buBt of Babastis (No. 95) near the western entrance to the theatre. The Penmafin-mawr stone {No. 123, beneath Caao VII.) is a fel- extathio greeaatone, which, from its tonglinoaa, forms a valuable saving material. It occurs as an intrusive mass in the Lower Silurian rooks near Conway, in Oaemarvonsbire.

Herpektene. CoKNiaa SEHPENTnraa. — Slahs, Ooltimns, Tavxe, fye., Noe. 20, 67, 83, 92, 93, 137, 149, 156, 158, 181, 191, 195, 209, 215, 220, 223, and 325. SerBfii on. Eastern Wail. Gybes Case III.

The Serpentine,— BO ciJled from the supposed resemblance of the rock to the skin of a serpent, — -which is found in quantity at the Lizard, is undoubtedly the most beautiful of the ornamental stones of this country. The vai-iegated colonra on which its elegance depends, are usually dark rich shades of red and green,irregularly mingled, and often relieved by white veins oT slaaiite or soap-stone. Near to, and to the eastward of, Cadgwith a very beautiful variety of reddish serpentine occurs, studded with brilliant lamina of dialtane, a, silicate of lime, magnesia, iron, &o., allied to augite. Both the serpentine and the sasociated steatite are essentially hydrous silicates of magnesia. Formerlthe steatite, from the " Soap Stone Book," near MnllioD, was sent in considerable quantities to Bristol, where it was used in the manufacture of carbonate of magnesia ; and at one period was employed at Worcester iii the manufacture of porcelain, but it is no longer worked.

For purposes of ornament this elegant atone is well adapted, being moderately soft, but not brittle, and therefore easily worked, while it is sufHciently hard to receive an excellent polish. It waa long thought that blocks of serpentine of a large size could not be obtained ; quarries have, however, been opened, and it is found that the size and solidity of the blocks increase with the depth from the snrfttce. There are few spots around the British coast more beau- tiful and grand than Eeynanco Covo near the Lizard, where the serpentine rock in all its varied dyca, is polished by the beat of the Atlantic waves, and, in contrast with the white aauda of the shore, is rendered still more striking and charaoteriatic.

Ieibh SERrsNTiHES.PiEnfera Noe. 43 oni 116. Bnreon on B. Wall. Slabs, Colwrnns, fyc, 74, 118, 178, 183, 208, .iiKi218. Taixa, 178. Serpentine frequently occurs in intimate assooiation with lime- stone, forming a mixed rock often of great beauty. The celebrated vord-antigtte {verde antko of the Italians] is a rock of this kind {see Noa. 18 and 19). Somewhat similar serpentinous marbles occur in Ireland, especially in Galway and Donegal, which afford beautifully variegated greea and white specimens. The green Connemaia marble, known to architects as "Irish Green," is obtained at Bal- linahinch, -erfrack, and other localities ia Galway, the most valuable quarries being situated near Clifden, whence this fine material is exported.

AsGLEBET SzSFES'ntiE.—Pediistal Ko. 196. Slab No. 224.

Among the metamorphosed Cambrian rooka of AngVaae-Stii™

Eerpentine occurs at several localitiea, fre(\wen.''A-:j B-aftiniviA.

80 The Halu

limestone. An example of this green serpentinona marble is fur- nished by the pedestal before us, from Bhoscolyn, near Holyhead.

Scotch SERPEyriNEs. — Obelisk No. 91. Cubes Nos. 90 and 161.

Serpentine rocks occur in various localities in Scotland, especiaDy in Banffshire and Aberdeenshire, and again in the Shetland Idee, where they form the matrix of the chrome iron ore. As will be seen from the specimens, very tine varieties for ornamental porpofles are obtained from Portsoy, on the ilorth coast of Banffshire, whence this elegant material was formerly exported.

Mabble.

It is a common practice to comprehend under the name of marik every stone which is capable of receiving a polish and of being applied to purposes of decoration, such as serpentines, porphyries, alabasters, and other ornamental stones. In strictness, however, the term should be limited to those varieties of carbonate of lime which are sufficiently hard and compact to bo susceptible of polisL

Although by no moans restricted to any particular strata, yet the marbles of this country are usually obtained from the palaBOzoic rocks, being especially abundant in the Carboniferous and Devonian systems. The Carboniferous or Mountain Limestone — which rifles in our northern counties in a broad ridge or anticlinal curve forming the Pennine chain — famishes valuable marbles in certain districts, especially in Derbyshire and on the borders of Stafford- shire ; whilst the fossiliferous limestones of the Devonian system- still older than those of the Carboniferous series — yield the valuable marbles of South Devon.

Derbyshire Marbles. Pilaster 99. Columns, Sfc. , Nos, 5, 35, 43i, 54, 58, 60, 63; 77, 79, 80, 81,86, 89, 98, 108, 110, 115, 117, 121, 128, 142, 143, 200, 214, 222, a'iid 229. Tazze, c. Nos. 82, 87, 167, 173, 183, 185, 193, 197, 203, 205, 207, mvd 230. Screen 3. Inlaid Work, Nos, 21, m, 97, and 107. Cubes in Case I.

The rocks of Derbyshire are rich in ornamental marbles, whioh from their beauty, and in many respects their curious characters, have been largely employed for decorative purposes. They are usually distinguished by their colour— as white, grey, dove, blue, black, and russet marbles ; or by physical peculiarities, dependent mostly upon their fossil contents, as bird's-eye, dog-tooth or mussel, cntrocbal, shelly, and breccia marbles. The limestone rocks of Derbyshire are divided into four classes, known as the 1st, 2nd, 3rd, and 4th limestones, which are separated from each other by an amygdaloidal greenstone, called toadstono, — probably a corruption of the German Todtstcin, or dead stone, in allusion to these inter- bedded trap rocks being barren of lead ore compared with the adja- cent limestones. The ornamental marbles are, however, mostly confined to the first three formations. From the upper beds of the 1st and 3rd series is principally obtained the well-lmown entrocTial or encrinital marble, so called* from the presence of abundant fossil remains of encrinites, or stone lilies." These were echinoderms belonging to the Crinoidea, — an order of which there are but few living representatives, compared with the abundance which existed in the Palasozoic and Secondary periods of the world's history ; the beautifuUy-formed and numerously-jointed Pentacrirms caput Ife- dnism, which is occasionally dredged from great depths on the coral reefs of the West India Islands, being the finest living example of

' . MASBfflR 31

this auoient family. The encvinite coneiflted of a, long johited coltimn attached by oue extremity to the seti-bottom, and suppoiiing at the opiwsite estremity a onp-shaped hodj', from which radiated Heveral artionteted anna fumislied with ciliated appendagea. The entire Btmoturo was rendered flexible by the internal calcareoua skeleton bein compoaed of numeroaa cylindrioal or bead-like jointa. Mr. ParkuisoQ states that the upper part of the skeleton of one species of euorinite consisted of nearly 27,000 osaicloa or small bones. These being dislocated are oemented together, in the marble, by carbonate of lime ; and being, in the prooesa of mannfaoture, cut in many dif- ferent sections, and poliflhed, they asenme a variety of forma. Many beautifal examples of these oncrinital marbles will be found in the collection.

The perforations in the centre of the joints afford facilities for atriang them as beads ; in this way those fossils were as roBanea, and they are still known in northern England aa St. - hert'a beads.

The black marble is obtained from tte second Umeatono, espe- cially in descending into Monsal Dale from. Little Longadon. Machinery for cutting and polishing this marble was first used at Aahford in the year 1748. The ehell-marble is also yielded by this aeries of rocka; this variety contains the remains of bnwlumiodous molluscs, 80 called from having two long ciliated amis (SpnxW, hrachiofi, an. arm, Toit, jjous, a foot). These are "Bhell-flah," fur- njahed with two Talvoa which are never quite equal, but since each valve is equal-aided the forms aresymmetrioal. In these points they differ from the ordinary bivalves, which are mostly equivalved bat EOTer quite equilaterol. Prom the resemblance of these braehiopo- dons Bhells to antique lamps, they are commonly called " lamp- shella.;" the hole corresponding to that which in a lamp admits the wick, serves in tho lamp-aliell for the pneaflge of the pedicle by which the animal attaches itself to submarine objects. The S;iiri/ei' and Froducta, two genera of the above class, are the moat abundant ia these Hmestonce.

The three upper limestones, from which tteso marbles are obtained, extend, according to Farey [General View of (he AgTicmUwre and Minerals of SerhTishire), over an area of nearly 51,500 acres.

In this collection the following localities are reesented, viz., — "Wirkaworth, Middleton, Bonsall, Matlock, Mether Haddon, ABport, Monyaah, Oneash, Sheldon, Ashford, Flagg, Stony Middleton, Bniton, Miller'a Dale, Bicklow Dale, and Tideawell.

A. cube of encrinital marble, extremely similar to some of the Derbyshire maxble, from the mountain limestone of Dent, in tho west of Yorkshire, is placed with the specimens Irom Derbyshire in Case I. Aa Dent was the birth-place of Professor Sedgwick a pedestal of this marble has been selected aa an appropriate support to tie bust of this diatinguiBhed geologist. (So, 159).

Tasm 201.

The marbles of Staffordshire present bat little varialions from those of the adjoining county. Their geological positions are the eame, and they present similar general characters. Specimens are exhibited from Wetton and Ecton.

The variety of coloured limestones which the two counties of Derbyshire and Staffordshire produce haa ii&tTiwi.\Vs\eft.to o.tkko faotui'e almost peculiar to them. Mosaic -wovV. -ne-rj \iftwSMJii.

32 The Hall.

description is executed in these materials. Indeed, many of tlie inlaid tables, tazze, and other ornaments, produced from Derbyshiie and Staffordshire materials, are worthy rivals of the far-&med Florentine works. In addition to the inlaid tables in this hall, there will be fonnd some interesting specimens of this kind of work in the horse-shoe case on the principal floor (p. 130).

Devonshibe Marbles. — Pilasters, 44 and 109. Screen 2. Columns, Slabs, S'c, Nos. 7, 8, 75, 127, 131, 132, 139, 140, 141, 144, 189, and 198. Inlaid Table, 106. Ciibes in Case I,

The limestone formations of Devonshire, from which ornamental marbles are obtained, may be said to be confined to the district! extending from Torbay to a few miles beyond Newton Boshell and Totness, and to the neighbourhood of Plymouth. These limestones belong to the group of strata known to geologists as the Devcmian system. The limestones of the Carboniferous series of North Devon ore rarely worked for ornamental purposes.

Marble works are extensively carried on at St. Mary Church near Torquay, the Babbacombe limestones yielding some interest- ing varieties of the red, grey, and variegated marbles. Many blocks are almost entirely formed of fossil corals ; these are known as madrepore marbles ; and Mr. Godwin Austen, who has examined these formations with great care, has clearly shown that the origin of both the Torquay and Plymouth marbles is of an analogous character to that of the coral formations now taking place in the Pacific Ocean.

At Ipplepen there is an extremely handsome variety of a reddish marble, and some of a nearly similar character occurs near Totness. The limestones of Plymouth are not generally so handsome as those of Babbacombe, but many very fine examples may Se ob- taiued. The quarries of Oreston, near Plymouth, furnished the stone employed in the construction of the Plymouth breakwater, and in connexion with the use of this limestone for that purpose, one curious circumstance has attracted attention. Between nigh and low water-mark the boring molluscs {PJwlas dactylvs ; pholas from pholeOf to bore) so perforated the limestones that it was thought necessary to replace them by blocks of granite, which, being much harder than the shells of these animals, resists their action. Some examples of these boring animals, and of the rocks perforated by them, will be found in the wall-case 43, in the upper gallery, eastern side.

Devonshire marbles are exhibited from Babbacombe, Bradley, Ipplepen, Buckfastleigh, Ogwell, Chudleigh, Kitley Park, and Plymouth.

Marbles of Bristol, Isle of Man, SccCuhes in Case II. Pedestal

161. Columns 13, 22, and 145.

The rocks which rise on either side of the Avon have been always celebrated for their picturesque character. This is not entirely dependent upon their bold outlines ; their varied colours and their irregular forms adding greatly to the grandeur of the scene. Several varieties of ornamental marbles are exhibited from the rocks of this district, especially from the carboniferous limestone of Clifton. Like those already described, these marbles are fossiliferous ; en- crinites are often common, fish-palates are detected in some, and many of the beds of coralline limestone are extremely interesting from the resemblance they bear to coral reefs. The Bristol marblesi,

.like those of Derbyshire, and unlike thoae of Devonshire, belong to the carboniferoTis formation.

Among the British mavblea in Case II. iriU be found a Hpecimen of the argillaceous limestone commonly called " Landsai'pa mark," in allueion to the peculiar dendritic mtirkings which it exhibits. It occurs in the Penarth or Ehaitic beds (p, 180), in the neighbourhood of Bristol ; and waa formerly much used for the manufacture of small ornaments. The Ammonite mariile (No. H] takes ita peculiar character from the Tast uumbers of Ammonites which it contains ; these fossils, somewhat resembling the shells of the living nautilus, will be described in another place (p. 178). Attention may also be directed to the specimens of conglomerate from Qlamorgaoshire (NoH. 129 and 199), which boionga to the New Hed Sandstone series, and i-ests frequently on the upturned and denuded edges of the carbouiferons limestone. The fragments forming the conglomerate or " pudding stone " are united by a cement sometimes calcareoits, bat nsaally magueeio-calcareous or dolomitic. A fine slab of this dolomitic conglomerate is eshibited from Drajcot, neai" Wells fNo. 12). With these dolomitic conglomerates may bo noticed soma specimens of the peculiar breccia-marble of the Isle of Man (No. 22). 'ITie black marble from the Carboniferous Limestone of the Isla of Man has been selected an appropriate material for the pedestal (No. 161) supporting the bust of ProfeBsor Edward Forbes, who was I native of the islana.

In Cose II. will also be found a few other mbles of less import- ince than those already noticed. These are from Someraetshire, Herefordshire, and South Wales. The carboniferous limestone of the Isle of Anglesey has furnished the black marble employed for the columns Nob. 13 and 145.

IBISH M.HBLES.— Pi?oster 48. Colurma, Sfr.i 37, 68, 100, 133, 184, 186, 187, niJ 194. Cufcee in Coie II. Ireland is rich in marbles ; indeed in no other part of the British Islands is the carboniferous liiQostone developed on so gi-and a scale. Extending over a great centra! plain, 120 miles E. and W. from Dublin to fialway bay, and about the same distance north and south, it forms the cliaracteriiitic rock thronghout the greater part of the island, and attains in the southern counties the prodigious thickness of nearly 3,000 feet. The. more valuable quarries are iu the connties of Kilkenny, Carloiv, (jolway, and Mayo; from these several varieties of marblB are raised, especially the black marble, next to which in importance are the dove, mottled grey, and whito marbles. The Galway marbles are well known, but the beds iu lie quarries are usually thin. It is auarried principally at Menlo, on the banks of Lough Corrib. The black marble of Kilkenny owes its colour to the presence of organic matter, and as this gi'adually becomes altered by espoaare to the atmosphere the colour suffers in Bimilar degree. White marble is obtained in Connemara and in - Donegal! the limestone of the formei" district is hard and fine, and is the strongest which has been found, while that of the latter ia so exceedingly coarse that it cannot be nsed for fine work. The white Connemara marble cannot, however, be procured in large blocks free from streaks, which pass through the blocks paraUetwith the beds. Those counties also produce the bluish white and pink tinted marbles.

Slack marble is principally obtained fi'om Kilkenny, Gralway, Churchtown, Donerail, Keny, and Tipperary -, wliHx, tactVAe. l-cani Ccmnemaia, Donegal, Charchtown, and Kerry a-D.ici>UiM,vei\TMMMi*

are Bcattered over all the districfca in which ibe limestones oeonr, fl. reddUh varietiee being found prinoipally near Armagh, aod ( Middleton and Ohurchtomi in co. Cork. The eientia -mafitte a chiefly from King's co.

The serpen tinoas marhln of Connemara has been already notiecC Bt p. 20.

Irish marblea arc exhibited from Clonouy, King's co. ; Pbimte Park and PinglftHa, Dahlin ; Mitohelatowo, Cork ; Kenry and A " keaton, Limerick; Minto, Gal way ; Ballinahinch ; the TrrrfTW P Monntainsj and BosBvella and Whito Craig Qnarrie.'.

Scotch M-txHLBs. — Screen 4. BlMkNo. 17. Cidies in CasetU- aM III.

An interesting variety of marble is exhibited from Tiree, in t Hebrides, where it occnirs aeaociated with the Laorentian gneiss.

The Tireo marble consists of a bsse of pink liracatone, throm which are diasominated granular masses of a dark green angS_ mineral, giving tho atone a porphyritic appearance. The burt Sir n. T. De la Heche in the library of this institution ia anpportac on a fine block of this marble.

AcAnAaTES.

SiSes of rdHidc. Columns Xos. 88, 177, mi 1S8. T,izza 17ft

Slab 65.

The tena cilLiinmhr waa formerly applied to Or stalagmitic vade of carbonate of lime ,much used iiy tho oncienta for omaioaiit pariiosea, eapeaially for the manufactore of small vases for .holuj preoioui) ointmcnta ; whence sueh vessels received the name "aiabaatra." This Oriental alabagter, of which the AlgMian " onyx-marhle" is a well-known modem example, must be carefiilly diatingiiiahed from the totally distinct mineral which is at present called alabaster ; that name being now applied to the fine ma ' or grannlar -crystalline varieties at gmeum (p. 43). This miiM which occurs abnndantly in the New Red or Keuper marls of midland conntiea, is a hydrous anlphate of lime, containing, when pnre, sulphuric acid 46-51, lime 32'5e, water SO'flS. Owing to the presence of oxide of iron and other impurities, the mineral is rarely uniform in tint, bnt ia generally clouded and streaked with red, Seen in the apecimena exhibited. These are from Fauld, in SI fordahire ; and ChoUaston Hill, near Aahboame, in Derbyshire.

The principal demand for alabaster is by the potters m Btaffbrd- shire, who form their moulds of plaster of Paris from it. It ij therefore called potter's stone, and sells at about 9s. per ton of 2,4(10 lbs. (the long ton). In working the potter's atone the fine blocks are selected, and aold to the tornerB of alabaster omamenta; No, 188 is an illuatration of tho prooesa of working and polishiitg this material for ornamental purpoaea.

Several varieties of alabaster occurring in Italy are cEtemriyely worked into ornamental objects, and as the stone ia extremely epfb, being indeed readily cut with a penknife, the coat of working is oni small, and alabaster ornaments are therefore imported into this cotmliy at a low price, The purest white alabaster ia worked M the Val di Marmolago, near Caatellina, 25 miles from Volterra, ir TufiCBJiy.

Slat£.

Thia valuable material is a highly indurated argilliiceonB rock, readily cleaved in cei'tain directions into thin laminie or plates i

and upon this peculiar fieaile Btructure dopenda to a great estent

The beds, dejjOBited originally as a flno muddy sediment, appeal- to have been subjected, long; after couBoliduttun, to the actun of intense lateral [ireHsure, the effect of which was not only to con- tort tho beds, but also to induce a re-arrangement of the particles of tha rock, the flattened etdes of these particles bein forced hj the lateral oompresaion into positions transverse or at right angles to the direction of the preBSure, and hence tho i-ock readily cleaves parallel to that direction in which all the particles are thus dcfi< nitely arranged. All contorted strata are not, however, cleavable.

EKperiments on slaty cleavage by Mr. Sorby, Dr. Tjndail, and other physicists have shown that a similar, though much less perfect, fissility may he artifloially developed by simple mechanical compression, the direction of the induced cleavage being always perpendicular to that of tlia applied prcaaure. The perfection of the natural cleavage is admirably shown by the Welsh specimens near the western window.

For furtlier information on this subject, aoo IfescriHve GnUIe lo Gm Bock Seciinens, 3rd editioji, p. 13.

Shiitea lu'e subject to considerable variation both in colour and texture : good rooflng slate should absorb but little water, and bo BO compact as not to be deoomposcd by the action of the atmosphere.

Mr. MeCulloch informs us that the use of slates in covering honseB ia entirely European ; from the Hellespont to China there is not a single slated house, though slate is as abundlint in Asia as it is in Europe. The daty on slatca carried ooostwoya -was repealed in 1831, and since that time it has been extensively employed for various purposes to which it was cot formerly ajplioable. Slabs which are not fit Jar splitting into roofing slates are now need as floorings, being cut with a circular saw into pieces of from half an inch to two . inches thick.

Slates of Nobth "Wales. — Column JTo. 15. GolhetUm at the sottth, or Jermfljn Blreet end of Hall, wegi side.

The slate quarries of North Wales have long been celebrated /or the excellent character of the slates which they produce. The moat important quarries are the following, which are given with their shipping ports, and the geological formations to which they belong : — i ,

ESS. :ESf™ic

Ffestiniog - Port Madoc, Zower SiJitrtan.

Llangollen - Llangollen, Djiper Siiarian,

Machynlleth - Abei'dovey, iMwer Silurian.

Boyal Slate Bangor, Cwmiriam

There are many smaller works near Conway and Oaernttrvon, The slate quarries of North Wales produce at least 360,000 tons of roofing slates and slabs per annnm. The annual produce of this district may be valued at 700,0001., and there are employed in the production of elates and slabs upwards of she thousand men and boys in North Wales alone.

Delabole Slate, of ilis Devonian Rocks. East side of Case VI.

The Delabole elate quarries, situate near Tintagei, in Cornwall, have been long celebrated for producing a durable matetiaV ccrai.- bining considerable lightues3 with strengtli. la lftflC-iLte ,a.Va,

'

86 THE HtltTi,

Survey of Cornwall, speaks of heailru/ aUU! (in many diatricti roofing BlAtea are Btill called huUhigi or )ieal!ngg, ]]robal>ly from or hffii to hide, and hence the name of liUr given to a tiler a elater] : — " In giAstance Oimne, in eokmr /aire, in icaighl li, f laMim hng, and generally caiTieth so good regarde as (jbettdee S I /or ftome provision) great ttoro it yearly eonveyed hg

piTu boa

of the workingB of Delabole. The Belabole quarries pradnoe a only roofing slates, but flagstones or brick alatea, which, are higfa.j esteemed for pavement* in paseages, courts, yards, &c. and tombstones. The inscriptions upon old tonibatones of the Delabott Elate remain remarkably perfect, showing its durability vrhen flS- posed to atmospheric influences. These slates aiv shipped I ' Tintagel and at Boscastle.

There are Other slate onarries near Boscastle and near Laonce ton; and also in DevonstiLre, at Tavistock, near Plymouth, and it Kingsbridge. {See Miiiil SUlUtiog for 1868.)

lu addition to the true cleaved elates other rocks posBeesiiig fc fissile fitructure are used for the purposes of roofing, and fjierefw was under the general name of " slates." Thus, the Stonesfield an CollyweBton slates are limestoneB easily split along the planes of bedding. Examples of these will be fonnd in the Hall (jiee p. 3"'

Sasbbtokes.— Cute* in Talk Casm IV., V., and YI.

A sandstone consists eBsentially of small ailiceous grains cementeft together into a solid rock. The nature of the cemenLing material if important, inasmuch as it deterraines to a large eictent the durabililj of the stone ; those varieties being most durable in nhich the csmeii 13 siliceous. lu many sandstones the grains of silica are accom- panied by small fragments of other minerals, such as felspar and mica, thus giving rise to varieties knovm ns feUpathic Btrnda' mtaaeevm satidstmie, &c. The formation of sandstone generally i Btmctively illastrated by a apectmen of recently-conaolidatw wioA from Newquay, in Cornwall, and many similar examples exiat around our western coasts, where hills of blown sand prevail. Thfi. water percolating throngh the upper layers dissolves the oarbonaleg of lime, and of iron, which nre re-deposited as cementing matflrialR on the evaporation of the water aa it filters throngh the lowflE strata of the porous sand.

In texture and colour sandatones are subject to considerable v .

tioD, according to the size of the grains and the nature of cement; the red, brown, and yellow colours exhibited by maoj) sandstones are due to the presence of peroxide of iron, either in al anhydrous or in a hydrated condition.

Sandstones have always been favourite materials with tbe aivhi- tot. and an extensive variety of specimens is therefore exhibited. Special description is, however, umiecessary, since every specimen, if distinctly labelled, not only with the locality, but in most cases with the names of the buildings in which it is employed; thnS rendering the collection highly instructive. This remark eqnftUjf' applies to the other bnilding atones in the Museum. '

Among the sandstones are exhibited several specimens of jmS> sfone Grit, This is the name given to a series of sandstones iter>: posed, in certain districts, between the Carboniferous LimestanA, and the Coal Meagnres, In tbe north of England, where the grit'jBi typically developed, it occnra as a coarse sandstone, in wh)3i tferf quartz frequently appears as large pebbles, sometimes even reaohinSf

' Iimestoses. 37

the size of an egg. From the poeitioa of the millstone p-it, immo- diately beneath the true coai-tearing rocka, it is not inappropriately called by the miners in some of our sonth-weatom ooal fields, the "Farewell Hock,"

Limestones of several characterB, from widely different locali- ties, era here gathered together. Moat of these are derived from liasaic and oolitic rocks, since paleeozoio limestones are, for the most part, suf&ciently indurated and compact to receive a pelish, and may therefore be clftssed as marbles rather than as ordinary limestonoB ; on the other hand, the limestonea of the upper cretaceous beds are nsually too soft for building pnrpoeeB ; chalk, however, is employed in some districts to a considerable extent.

The Liag formation, as it 1b called, — the term being probably corruption from layers, as indicating the mode of occurrence of its bedB— uatenda over a great length of England, stretohing in a north-easterly direction from near Ijjrae Regis, on the Dorsetshire const, to Hedcar, on the couat of Torkshii-e. The lias limestones — which are often of a blue tint — aro usually more or less argillaceous, and form, when burnt, a valaable hydraulic cement: whilst the finer stones are nsed not only as building materials, but alst) as paving slabs. Some of the liaa limestones strongly resemble those employed for lithography ; tho truo lithographic stones are obtained from the oolites of Solenbofon, in the Bavarian Jura, a short distance from Munich.

Immediately succeeding tho lias is the great group of OoIUk rocka which traverse England from the coast of Yorkshire to that of Dorsetshire, in many places afibrding enormous quantities of escellent building material

The name " oolite " (w&i', do", an egg; AiSm, lilJioB, a stone), is derived from the limestones of this goup, being, for the most part, made up of small egg or roe-shaped paiucles, width are spheroidal concretions of cai'bonate of lime ; each grain usually presenting a, concentrio structure, and enclosing apajticle of sand, or some other snbstance which has served as a nuieus. It should, however, be remembered that all the limeatonea belonging to the oolite-series do nob present this peculiar teKtare ; nor, on the contrary, is Each oolitic Btructure confined to rocks of this formation, many of the palieozoic limestones in certain districts being lithologically true oolites.

The lowest division of tho oolitic series, known as the InfarioT Ooii(, yields some excellent building atones which are estenaively worked in the neighbourhood of Cheltenham. The Painswick stone, for example, comes ii-om this series, and is of extremely fine quality.

It has been sliown by Mr. J. W. Judd, that the rock which is known as the LincoloBiiire liraestoue, and was formerly referred to the Great Oolite, should properly be regarded as a member of tho Inferior Oolite. The Aiicaster, Barnnck, and Ketton stones form valuable materials for Brohiteotural puriioses, and are quarried ia this part of the geological series.

Erom the Great Oolile, wliicli occupies a higher geological position than that of the Inferior Oolite, the celebrated 5uWt etoiie is obtained. The principal quarries of this stone are those of Bos, Coombe Down, Monckton, Parleigli, and Corsham Down. lo. the Henry the Seventh's Chapel, the CDQvn\ie"Do>'sii sldwe costing alioat 40,0001.

38 The Hall.

Bath Ktonc ]k>sscshos an agreeable warm tint, is worked with greiik cuHC, and may bo obtuine<l in blocks of large size ; but TmfoTtiiiuite}f it ducd not iMJs.ses.s great durability when exposed to the otmosphen of large towns. It is, however, extensively employed for ams mental mouldings and sculptured decorations. One peculiarity con- nected with this and other free-working limestones is that they 1xK:omo in some dogroc hai-der on their surfaces by exposure to the weather. This is said to arise from a slight deooznposition taking place, which will remove most of the softer particles, and leave the hardest and most durable to act as a protection to the remainder.

The valuable Portlnml stune is derived from tiie Upper Oolites of the island of Portland, near Weymouth. The quarries from which the stone is obtained, — of which there are at least fifty, — are prin- cipally at the north end of the island. The conditions under iddch the Portland stone, with the overlying Purbeck beds, occurs, will he best understood from the following account of the beds, abstracted from that given l)y Mr. Webster.

Immediately nnder the soil is a series of thin beds, abont three feet tliick, called elute by the (piarrj-men, consisting of limestone d a dull yellowish colour. Below this, is another mass of calcareoui stone, of a softer and lighter colour ; it is divided into two by a slaty bed, the uj)per being called aiah, and the lower the soft hv/rr, Tbeee are between four and five feet thick.

Below this is the dirt heilf aljout one foot thick, which consists of a dark brown substance containing much earthy lignite. In it are found considerable numbers of the fossil trunks of coniferous and cycadeous trees, of which a fine specimen will be found in the NX comer of the Hall (No. 53).

A limestone rock, ten feet in thickness, then occurs, which is called the top ca2)t and below that another, distinguished by its cellnlor character, and known as the school cap, which is about three feet thick. Under the school cap is a layer six inches thick of flint or

The bed below this is the first which is worked for freestone, and is called roach. Its thickness is variable, being in the mean about fifteen feet. This is the most valuable bed, and blocks of a vast size are raised from it for the London market. Below the toogK is the hed, which is not of much commercial value ; this is about five feet thick, and underneath it another good bed of freestone, about Btx feet on the average in thickness, called the white hed, or best hed. This lower bed is worked whenever it is found in convement situations.

Previously to 1623 this stone does not appear to have attracted any attention. iVom 1660 it has gradually grown into use. Inigo Jones restored a portion of Old St. Paul's, " casing great part of the out- side, and adding a grand Corinthian portico to the west front, all of Portland stone." St. Paul's Cathedral, and many of the churches and other large buildings erected in the reign of Queen Anne, were constructed with stone very superior to that now generally employed, as far as regards durability. The quarries from which Sir Chris- topher Wren obtained the Portland stone which he employed have been long- deserted, the only reason assigned being that the mer- chants find that they cannot sell that stone on account of its being a little harder, and thereby more expensive to work.

No. 47, placed under Case IX., is a large fossiliferous slab of Portland stone from Tisbury, in Wiltshire ; and a fine specimen of Ammonites giganteus, No. 73, a characteristic fossil of these beds, will be found at the base of the statue of Hercules (No. 72).

Overlying the Portland series are the fresh-water beds of tbe Pm*-

beck grouri, so called from the district known as the late of Piirbock in Doraetflhirc, irhere this t'unnatiou is well eihibild. From the upper beds of this grouu u obtained n compact shelly fraah-water limestono kDown no PuTbeeli nmite, of which a Bpeoimen ia oxhibitod in Caae I. The marble abounds in ofgouio remains, and indeed ie a congeries of iresh-wfttar auail shells {I'ahidiiMe), intermixed with the , Bhells of Bome minnte cruBtooe&na. It occurs iu beds which vatj in. thicknesa from aixtonineiDchea, and it waa much employed formerly in this country for mating tbe slender shafta in Gothic chnrchea; but the introduction of foreign marbles hoa occaaioncd its use to bo - almost diacoutinned.

Very similar to this Pui'beck' marble ai-e thcfraHh-waterlimeBtonea occurring in thin local bands in the Weald clay, and known as Petworth or Sitssex marhle. They abound in casta o( pahidiruj!, but of a apeeies different from that which characterizes the Parbcck limestones.

The Kentish rag, of which a specimen is exhibited iu Case VI., from the Iguauodou Quarry, ueaT Maidstone, is a hard ailiceona lim.e- stone from the Hythe beda of the lower groensand, wiiero it oocnrs asaoiHated with a soft calcaroua sandstone known locally ae " haa- aock." The rag stone ia extensively nsed tor building ijorpoaee, the total qoaaititj; shipped being about 55,000 tons per annum.

Although Britiah building stones alone ore, aa a rule, admitted into the collection, an exception ia maae in favour of the celebrated Caen eiowi, a cube of which is placed in Case V. This NormoB oolite, which is an equiralont of our Bath stone, was held in high repute by the architects of the middle ages, and waa largely employed in this country, Amongst the buildings in which it waa used may be Specially notioed the Temple Church, and Winchester and Canter- bury Catiedrals,

Before leaving the group of limestones, attention should be drawn to the varieties of thisrock, which exhibit a fissile atnicture and are thus capable of being split into alaba sufficiently thin to be uaod for roofing purposes. "oieHe " elates " wore largely employed by Gotbio architects, and are atiU used in ecclesiastical architecture, though geaerally superseded for domostic purposes by the highly .cleavable Welsh slates. The principal fissile limestones are the Stmtesfield elate, which occurs at the base of the Great Oolite in Oxfordshire, and the Oolhjiueetmi slatet which aiva found in the lower beda of tho LiiicolnshirB Oolite, in Hutland ; specimens of both kinds of slate, with the tools used in working them, are exhibited in the HaJl. The Oollyweston slates bj fully described by Mr. 3. W. Judd in his "Memoir on the Geology of Eutland," 1875.

Dolomites. MiusEsus Liubstoses. — The done employed ilte building. Antinous as Saechae, No. 61, eastern gide of Hall. Cvbea iH Case VI. The Gimiirtiani Miiwna, No. 85. The Dolomites, — so called hecauae they were first examined by the French geologist, Dolomieu,— are essentially limestones in which the carbonate of lime ia replaced to a greater or less' extent by car- bonate of magnesia. These magnesian limestones are largely developed in the Dpper Permian beds of tho north-east of England, where they often exhibit peculiar concretionary atructoresf of which examples will bo found in the collection of rock specimens in tho upper gallery. As building maierials the magneaian limestones are highly important, well selected varietiea being exceedingly durable, especially when presenting a crystalline texture, and con- taining the carbouatea of lime and magncaia in noailj e proportions.

40 The Hall.

Tho more important (marries from which the mMiiesian limMtae 18 obtained are those of Anston, of BrodBworth XSeydehyf tsod BhI Nook, near Doncaster, of Hnddlestone near Sherborne, aad of Smawse near Tadeaster, in Yorkshire ; while in Derbyahire ihB Btone of fine quality is obtained at BolsoTer near Ohesterfiaid, aid in Nottinghamshire at Mansfield Woodhocue. An analjRi of Bolsover stone gave :

Carbonate of lime - - - - 51 " 1

Carbonate of maesia

Oxide of iron and alumina

Silica

Water and loss

The specific gravity of a dry mass of this stone is 2 316. weight, in the ordinary state, of a cube of two-inch sides, 4890*8 grains; the weight of the same stone when weU dried, 4881*4 grains ; when saturated with water it weiphed 5,042 grains. llisiB an important consideration in the selection of any pnildmg atooa One specimen from Cadeby absorbed one-fourth of its balk of wator. A stone absorbing much water is liable to disintegration, irhm, during frost, this fluid consolidates. M. Brard introduced an eoperi- ment for determining the effect of frost on stones, which was highly recommended in France. The exact mode of experimentalising ifl to dip measured samples of stoue into a boiling solution of GlauberB salts, and leave them in it exactly half an hour. They are (hea removed and hung up, each by itself, over a vessel containing some of the above cold saturated solution. Within. 24 hours a white efflorescence will appear on the surface. The stones must then be immersed in the liquor in the subjacent vessel, so that the crystals disappear. Whenever the efflorescence forms, the stone is to be thus treated. It is said that the tendency to disintegration in any stone will be shown by this treatment. By such an experiment, continued for eight days, the Bolsover stone disintegrated to the extent of one grain and a half. It was however, shown by the late Mr. 0. H. Smith that this process differs materially from the action of frost, which it is intended to imitate, since the crystallization of Glaubers salt is unaccompanied by that expansion which attends the freezing of water ; indeed, many highly durable stones disintegrated under this treatment to a much greater extent than other stones well known to decay rapidly on exposure.

In some of the chemical works on the Tyne the dolomites of the northern counties are used for the production of carbonate of mag- nesia ; while the magnesian limestones of Marsden are taken in considerable quantities to Sunderland, whore, being treated with sulphuric acid the magnesia is dissolved out, and from the liquor obtained, Epsom salt {sulphate of magnesia) readily crystallises. A considerable proportion of the Epsom salts now sold is thus obtained.

Ghinding and Polishing Stones. — Case VIIL

There are tolerably numerous varieties of materials which are used for the purpose of giving fine edges to cutting instruments, or a polish to metal and other surfaces. The collection in this case, mostly presented by the late Mr. E. Knight, is intended to illus- trate this class.

QBnnnNO isn FOUSHnra stones.

abound in tbe coal diatricts of Northumberland, Durham, York- shire, and Derbyshire. According to the varioiiB degreea of density and coarsenesi they are employed, espeaially in Binniaghttm and ShefS eld, for grinding or for giving a smooth and polished surface tJ their different wares.

At Bilston, in Btatfordahire, is found lying above the coal a pecu- liar Eandstone, finer than tbe above, and of a very sharp nature. This is quarried entirety for the BiUton griudetonea, which are of great excellence.

The earpeater'e inillslone is a hard and close variety of the York- jhire sandstone. The northern conoties yield several varieties of grindstones, which are much in request for different descriptions of work. Yorletihire gritt for example, is used for polishing marble and the copper plates for engravers. The Sheffield grinihtone is s. hard and coarse stone used for common purposes ; it ifl found at Hardsley, 14 miles north of Sheffield. The Sheffield hhie timie is a fine-grained stone, used for finishing fine goods. The act of grind- ing on a blue stone is termed " wMttmiing "- — the Sheffield whittle firom the earliest periods being in all probability ground on this Btone. Wickersley stones are obtained about nine miles from Sheffield, and are much nsed by the cutlers for grinding.

Devonshire hats are in much repute. These are porous fine- gi-ained sandstones found in the quarries of Black Down ClilT, near CoUnmpton.

Home Slates. — These are slaty stones nsed in straight pieces for Bhari>ening tools after they have been ground on revolTing grind- atones. The more important varieties are the following : —

The Notiray ragsfone, which is the coarsest variety of the hone slates, is imported in large naimtitieB from Norway. In Ohamwood Forest, near Mount Sorrel, in LeiCEstershire, particularly from the "Whittle Hill tinarry, is obtained the Clianileij Forest stone, said to be one of the best substitutes for the Turkey oilstone, and it is much in request by joiners and others. Ayr storre, snahe stone, and Scotch stone are used especially for polishing copper plates. The WeUh oihiwie is almost in equal repute with the Charnley Forest stone i it is obtained from the vicinity of Llyn Idwal, near Knowdon, and hence it is sometimes called Idival ebme. From Snowdon is also obtained the cutler's green stone. The Dereonshire oiktonea, obtained near TaviBtock, which were introduced by Mr. John Taylor, are of excellent quality, but the supply of thom being irregular, they have fallen into disuse.

'JHie German rasor hone has been long celebrated. It is obtained from the slate mountains in tiie neighbourhood of Rntishon, where it occurs in the form of a yellow vein running through the blue elate, varying in thickness from one to eighteen inches. When quarried it is sawn into thin slabs, and those are generally cemented to slices of slate which serve aa a support. Sometimes, however, the yellow and the blae slate are cut onb naturally comljined. There are several other hone stones, which, however, iequirc no particular notice.

The Turhe'j oUsione is said to surpass in its way every other known substance, and it possesses in an eminent degree the pro- perty of abrading the hardest steel : it is, at the same time, of so compact and close a nature as to resist the pressure necessary for diEffpenJng a graver, or Miy instrument of that description. There

toe white and block vnrietios of the Turkey oiletoue, tite blaokbehig the h&rder, and it ie irarUd in iomcnhat larger pieces tbi white ; they are m the interior of Asia Minor, and Invngiik down to Smyrna for sale.

Among the examples of miacrftl substances employed as bnntuhcn will be fonnd a gnooimen of iigiUe (p. 133), and a piece of kfemaiiUm red iron ore (p. 108) ; the latter mineral, although exhibited nnda the name of blood, ttime, ia to be carefully dietingDished from tht " hioodBtonB" of the jeweller (heliotrope), which is a jaspery vuietf of silica to be aubBequently noticed (p. 1).

The corundum and emery exhibited in this caee are varietira of aburniiia, a mineral which is presented in its forco in the and aapphiro : and which will again be met with the horse-shoe en on the principal floor (p. 134).

Smery ia obtained from Capa Emeri, in the ieiand of Naxos, and from several localities in Asia Minor; it occora also in Jersey ani Guernsey, in Poland, Sasony, Sweden, and Persia, and Bomehega diBCOverieH have lately been made in Chester, Maasachuaetta. its escessive hardnesB it is used for polishin", for which purpose ib IB prepared by grinding and elentriation, ami then sold nnMT &B name of jtew of emery. The hardness of the Indian sapphire being considered as 100, that of comndum is 77, and that of the emery of Kas(M, 46.

In addition to those polishing atouea which have been e8pe(nally mentioned, there will be fonnd on tho opposite side of the oaee aeries from France. The celebrated "Burr Hfonus" of La Perth- BOnfl-Jouarre (Seine et Mame) arc unequalled for griat milla. The combbied ronghnesa and hardness of this tertiary quartz depoait give it immense adrantages, espensive though those Btones are, it oonseqnence of the neoessity of cai-efnlly pict:mg them together.

The traohytic laTa from tho ertinct volcanos of the Lower Eifel fomisb 08 millstonoB which have long been justly celebrated. They were well known to the Romans, andaro still extensively qnstried at Niedermendig, near Andemach, whence they are sent down the Khine to Holland, and es:ported to moat parts of the globe. Undw the name of "Dutch Blue Stones" they were formerly muchnaed in this conntry.'

From Milan, in the Greciao Archipelago, exhibited i trachytic millstonea, which are not only extensively used in Gn but are alao largely exported to Turkey and Trieste.

In the same case are several varieties of the hone slates from Cornwall, hat the hones from the Cornish slates have not, as yet, come into anything like general use.

The Tahere scythe atones are formed fi.'om tho millstone grit of the Flintshire coal-field, on tho estate of Sir Pyers Mostyn, Barb From Gronant, neta' Tcro, is exhibited in Case VII. a specimen of chert, which occurs in the Mountain Limestone, and ia almost exclusively employed in tho Staffordshire Potteries for grinding

An artificial grindstone and an emery wheel, prepared by Mr Banaome'a procesp, are exhibited in this case. They are said to be more uniform in texture and to have a sharper cut than grindatonoB of natural materiaie. The preparation of the artificial atone, of which the material of those grindstones is but a modification, willbe explained at p. 45.

M

GiTSUM. Plasier Pahis. Cbmestb.— Case IX. Oaet of hut cf

Prof. Jules, 64 ; of Apollo Sehedere. 120 ; of Dying Gladiator,

163i of GveeU F<Mfl,lli aindofArmowr,iSi- Pavenentin Keene

Cement, 78, Benson amd Logan'd Cemenl, lOi. Scptarfa, 69, 126 ;

mid Ml Case VII.

The WBil-known mineral (hjpai;m is & hydrous sulphate of lime

OociirriiiK ahuudantlj iu the Kew Sed oi' Keuper Mark, often

Baaooiat with rock aalt. 'When trftoaparent and oryBtallized, it ia'

known as g<Hen,ite, and wlieu librona, ba satin, spar epecimens of

both varieties will bo foond in this case. The fine Bemi-cryatalline

form of gTpauoi termecl Alabasier has been already noticed as an

ornflineatal atone (p. 34). All these substances are Datural hydrates

but the mineral called AnydriU, of which a specimen is exhibited

from. Eerbyaliire, is a pure aulphate of lime, destitute of any easentiaJ

water, its Qonipoaitioii being, finia, 41 ' 18 ; sulphuric acid, il 82.

Wben gypaum is calcined at a moderate temperuturo it paiiiB with the whole of its water, and baa then a compoaitioii resembling that of anhydrite. This calcined gypaum when reduced to power forma a well-known Plaster Tuns, of which three qualitiea are exhibited. This name is derived from the circumataace, tiiat the mineral from wbich the plaster is obtained is found in. abundance in the tertiary deposits of what ia called the Paris baain, especially at Montmartre. Mixed -with snfEcicnt water to convert it into a paste gypsum eagerly absorbs the liquid, and returning to its original Eydrated condition, rapidly BoHdifi.e8 or sets, u, however, the gypaum be oTerburet tnis setting ia prevented, and in practice to ensure rapid consolidation, it ia often desirable not to etpel the whole of the water from the mineral. A certain amount of impurity in tlie original gypaum appears to operate favourably catier than otherwise, the superiority of tho Iench plaster of Pai'is, which acquires a greater degree of solidity tH" any other, being re- ferred to its containing about 12 per cent, of carbonate oflime. M. Gay Luaaao says tliat tbe purest pltistera arc those which harden least J ne does not, however, consider tlua to depoad upon the pre- sence of the carbouate of lime, but on the original hardness of tho stone.

The aggregate annual consumption of gypaum in this country has been estimated at 30,000 tons, valued at 10,000?. Tho largest quantities of plaster of Paris ai'e used in the Potteries, tbc pottera employing it to form their moulds.

The facility with which, by meana of plaster of Paris, copies of any objects can be obtained, renders it of great value in multiplying the flneat works of ancient and modem art. Some esb-aordinary applications are shown in the copy of a cup by Benvtnuto Cellini in tho case, and by fac-aimiles of ancient aimour, Wo. 40, which are hung upon tho wall against the oBfitem ataircaae. Tbe colour in theae esamplea ia given by rubbing bronze powder over the surface of the dry pluater.

One interesting proceaa ia shown in which the gypsum is heated to espel neaily idl tho water ; it is then tinted with colour, and sah- aeqnently re-aaturatod witli water.

FictiU ivory, of which there are several examples, is plaster of Paris, which, ailer drying, has been made to absorb melted e perm a- ceti by capillary action ; or it may be prepared according to Mi'. Francni'a proceaa as follows ; — Plaster and colouring matter are employed in the proportions of a pound of superfine plaster of Paris to half an ounce of Itahan yellow ochre. Thoy are iiituaa.toVj aivse. by paaaing them thi'ough a fine ailk aicye, ani u - 'i'i.'a'ij\&'VQ.*;A)i

44 The Hau.

in the uenftl way. It is first allowed to dry in the open air, and b then cojcrully hented in an oven ; the plaster cast, when thoroaglilv dry. ia soaked for a (|aartr of an hour in a bath containing equal parta of white wax, spermaceti, and Btearine, heated jnet & little beyond the melting point. The cast on removal is set on edge, thai the saperfiuona composition may drain oft', and, before it cools, tie surface is brushed, with a brush like that known by house paintere as a, aaeh tool, to remove any wax which ma have eettledui the crevices ; and finally, when the plagt-er is quite cold, its surface is polished by rubbing it with a tuft of cotton wool.

Some oaata, as will be seen, ore in very high relief; these are jnftdo in eloatio monlds.a composition of glue and treacle, which admits of being out from the "under catting" withoni injury. This process enables any one to copy and preserve the game of ancient and modem art in a material which is at onoe pleasing and moderately durable. Ancient ivories can be exactly imitated the introduction of a little more colour, or by painting the plastw in wator-colonrs before it is dipped into the composition .

By subjecting plaster of Paris to certain methods of chemical treatment, it may be hardened to a considerable extent, and fl)M becoming much less liable to injury, its value as a cement is greUly increased. Many of these procesaee of hardening are illustrated in the collection.

Keem'ii Cement, according to the specification, is thus prepcud :— Dissolving one pound of alum in a gallon of water, this solution is used for soaking &t pounds of gypsum calcined, in small InmpB. These lumps are then exposed for eight days the air, ajid eJler- warda calcined at a dull rod heat.

They are then ground and sifted. The fine powder thua produced is mixed with water into a paste, which may be employed a.s ordi- nary plaster of Paris ; upon setting, it forma a body of great at pactness sJid durability, which can be polished or coloured without difficulty. If half a pound of proto-snlphate of iron (the common copperas] be added to the solution of alum, the resulting paste has a fine cream colour, and the hardened mass is said to resist ' action of the atmosphere.

Among the specimens in this case w'ill be found a series iUustrating ' Mr. Wood's application of blast, furnace slag in forming cement ana mortar. The slag is run from the furnace into cold water whereby it is granulated, and this " slag sand " is then mixed with lime.

1'he Parian cement ia prepared by soaking the plaster in a solntiM of borax instead of one of alum. This is exemplified in the cast of the " Dying Gladiator " and its base (No. 103), as well aa in the coloured cement on the stairs, in which Derbyshire marbles, to be found in the collection, ai-e imitated, for the pnrpdse of showing tO what ext-ent the realization of a natural stone can be Beoored in an artificial one. Marlin's cement is formed by combining

Eearl ashes (bi-carbonate of potash), and alnm with the plaster, ydrochloric acid being sometimes added to prevent an alkaline ro- action.

Scagliola differs from all these cements, in consisting of small fragments of marble, and other ornamental substances, embedded in a base formed of a mixture of plaster of Paris and glue. This waa the invention of Gnido del Oonte, an ingenious mason of Oari, neat Corregio, in Lombardy, Scagliola waa much employed by the Florentines in some of their most elaborat* works.

Eoman cement is made from the septaria, or " turtle stones," which occur abundantly in many beds of clay. Great quantities of

these cement-Btoaea are at proBCut procured by dradgmB off the coa>at of Hampshire for the septaria which have been derived trom the Bartou olaj. They ai-e alao found largely at Harwich and in the Isle of Sheppey, and are dredged up in Chiohester harboor, where the yare derived from the London clay. Some typical specimens are exhibited in Case VII.

A Bsptarl-wa is simply a nodule of argillaoeoua limeatone, often containing in its interior an organic substance, serving as a nacleaa around which the limeatone aggregated. The contraction Buflered during desiccation haa prodaoed fissures, or cracks, which have anb- seuently been filled \iy deposition of carbonate of lime. Those veins of caloite being disposed with tolerable regularity through a darker base, produce, on section, a peculiar pattern, which is well seen in the polished slab {No. 62).

The cement-atones are calcined in kilns, then ground, sifted, and packed in casks. The cement so prepared jKissesses the valuable property of rapidly hardening under water, a property which appears to be due to the presence in the septaria of certain adven- titious ingredients, especially silicate of alumina and iron. The following maylje taken aa an average analysis of the English cement- stones yielding this hydraulic mortar : —

Carbonate of lime, 65'7; protoxide of iron, 6'Oi silica, laO; alumina, 6'6.

Benson and Logan'e meiallie WTiMnf is a comjionnd of the ground slag from the copper- smelting works at Swausea with ordinary cement-stone. A sketqji painted in colours on a ground of this peculiar cement will he found on the western wall (No. 104). Near this a plftoed a stereo-chromatic painting on baked clay (No. 114), illustrating the application of alkaline silicates to the flsing of colours on exterior walls. The clay, or other substance serving as the painting ground, is prepared by impregnation with a solution of axi alkaline silicate, or " wafer glaeg," and a surface is thus obtained, to which the colours readily adhere. The painting, which may be Bxeonted with perfect freedom unlike the ordinary mode of fresco painting, is finally fixed by a coating of water*glass, which effectually preserves it, from, the action of weather, even in the most exposed situations. The specimen before us is by Echter of Munich, after a design by Kanlbach.

In Case VII. will be found some apeoimenfi of artificial stone, prepared by Mr. Fred. Baosome, of Ipswich. This gentleman haa at different times patented several proccsaea for this purpose, but the general principle consists in nsing water-glass as a cement, by which sand la formed into a compact stone, remarkable for its hi"h cohesive power. By the aide of this artificial stone are some speci- mens of flints which have been acted upon by heated soda in the preparation of the alkaline silicate employed by Mr. Eaasome. Ordinary flints are subjected to the action of a strong solution of caustic soda in digesters under steam pressure of from 60 to 80 Iba.to the square inch, and are rapidly dissolved with production of solution of silicate of soda. In 1870 Mr. Kausonte effected a great improve- ment in the manufactore of his artificial stone. He mixes the Farnham stone, or soluble silica with silicate of soda or of potash, lime, sand, alumina, chalk, or other convenient materials - the aUtaline silicate is then decomposed, the silica combining with the lime to form an insoluble silicate of lime, and also forming with some of the materials a silicate of alumina, whilst the oaustio alkali set free by the decomposition seizes npou the soluble silica of the Famham atone and forma a fresh Bilicato, vi\iicV m \,-a!rQ.\'!,

deeompoied by more lime. The new matoriBl which has been calU Aptenile, is exhibited in this case. Mid its appUeatian is fiird ilnisireid by the large vbas on the staircase leing to tia principal floor.

Tesselited Pavements. — Centre of Ral. Slabs, Nog. 78 emd 96.

The design or the fine specimen in the centre of the hall hts been taken from varioaa tesselated pavements fotmd, doj-ing 1793, 179i, and 1765, in the remains of a Bomau villa diecoyered at Wood- Chester in GlOttcestershiro. A particular deacription of this will be fonnd in Samuel Xifson'a Woo(Miesl Antiqiutie. Some additioDsl examples of mosaic pavements will lie found conDccted with tiu Bpeoimens of ancient and modem mosaic on the principal flira (p. 165).

Thetessersi of which the pavement is formed, nnd the encaustic tilea by which it is surronnded, were mannfactnred by Hesaa. Minton & Co., of Stoko-npon-Tront. The process of manufacture is an interesting one. Mr. Prosser invented a machine for oaaKSa- iug clay, which has been employed by Meaara. Miaton & Co. Porce- lain clay, either white or with an admixture of colouring mataiia], ia taken in what we may call a dry stete, the clay containing only its hygroaeopic water ; it is placed in moulds the aizeg and shapes of the reouired tesserte or tilea, and, being subjected to pressure, its particles are brought bo closoly together that they readily co- here, and the whole comes out a solid piece. For the purpose of giving the greatest degree of hardness to it, it is subaequeutly ex- posed to heat, when the materials for the formation of the mosftio are ready for use. Another variety of the same manufactore will bo seen still nearer the entrance. These pavementa'C exceedingly durable, and in many sitnatioua posaeas advantages over every other kind of flooring, irrespective of the artistic beauties of wHoh they admit. The tiles are of the same general character; SiTaruty of these will be found with the pottery collection in. tl nppiBE room.

CRoaBLES, Clay aitd BJack LcaiJ. Case X.

Here will be found examplee of the application of clays to the manufactai-e of melting pots and crucibles. As liiese vessels hiera to be exposed to the intense heat of fnrnaoes, it ia important tiiat such clays should be selected for their mannfactore as are very infusible. Such aa contain much potash, lime, or other bases readily ftise into a semi-vitreous mass ; but, on the contrary, thoas which contain a large proportion of silica are highly refractory. To diminish the contraction and expansion which claya nndetBIO on exposure to sudden changes of temperature, aa also to increase their iafusibUity bo that collapse of the crucible may be prevented, the clays are generally mised with certain infusible materials, sooh ag free silica in the form of sand, gronnd fragments of old crocibles, and finally powdered coke or graphite.

The cJuef commercial varieties of crucibles are represonted in this case, the greater portion having been acquired from the Gkeat Exhibition of 1851.

With the crucibles ia exhibited a collection of fire bricks, sonong which may be specially noticed the valuable Binae hriek, formed a highly Bilieeoua rook occurring in the Vale of Neath in OIainDr>i ganshire, and known locally as " Dinas clay." The powdered rook, mixed with a small proportion of lime to act as a flus, ia moulded

r TbASALT. — NATIVS. COPPER. 47

into brioka, wbioh are liiglily refractory, and are heuca largely employed for liaing copper-smelting fumacea.

Tlie cae also contains flre-brioks manufactured from the ooal- meaeure clays and shales of Staffordshire and Scotland, as the Stonrbridge, Garnkirfc, and Glenboig fire-bricks.

Basalt. — Golunmsfrom Ote Gianl'a Cemieway, Wo. 176.

Tiiese epecimenH well illustrate the peculiar colnmnar structure which, basalt Tevy frequently assumee, and on which depends the charaoteriatio scenery of the Giant's Cansewayj the Isle of Staffu, and other well-known basaltic districts. The btisalt of which these are composed is a dark-colonred, fine-grained, igneous rook, com- posed of an intimate mixture of felspar, usually labradorite, nnd augite, often associated with certain advcntitions minerals, as olivine, magnetic iron, Ac. The columns, as seen by the specimeuB exhifaitiMi, aie large aii-sided piliare, each prism being usually terminated by a convex ftioe at one end, and a OMTesponding con- vexity at the other ; and by a kind of ball-and-sockot joint thus formed, the individual columns are articulated.

The columnar structure of the basalt has been artificially pro- duced. Mr. Gregory Watt melted seven hundredweight of basalt, and kept it in a furnace several days after the fire was reduced. It fused into a dark-coloored vitreous mass with less heat than was 'necessary to molt pig iron. As refrigeration proceeded the mass became stony, and globules appeared; these enlarged till they pressed laterally against each other, and became converted into polygonal prism s.

tn Case Vil. are some esamplea of the appiicatiou of a basaltic rock, after it has undergone fusion, to decorative and omameittal pnrposea. Messrs, Ohance, Brothers, of Birmingham, adopted the process of melting the Rowley rag, b. basaltic rock forming the plateau of the Bowley hills, neax Dudley, South Staffordshire, and then casting it into moulds for architeaturai ornameots, tilea for pavementa, Ac. Not only the Rowley rag, bnt gi'eenstone, whin- stone, or any sirnilar rock may be used. The material is melted in a reverberatory furnace, and when in a snfiiciently fluid state is

foured into moulds of sand encased in iron boxes, these moulds aving been previously raised to a red heat in ovens suitable for the purpose. The object to be obtained by heating the moulds previous to their reception of the liquid material is to retard the rate of cooling! as the result of slow cooling is a hard, strong, and stoay substance, closely resembling the natural stone, while the result of rapid cooling is a dark brittle glass, similar to obsidian.

liiBSE Mass of Kativb Copper from the Mine at the GlioBteroft,

MiilUotx, OomimU, ifo. 175. Trenonee mine, from which this remarkable specimen was ob- tained, was worked near Mallion, close npon the junction of the serpentine with the hornblende-slate rocks.

It is not unusual to find, in the fissures of the serpentine rocks, masaes of native copper ; these have frequently induced a further BCarch for mineral treasure, which has rarely been snccessfnl. In Trenance mine numeroaa deposits of a similar character to the

rcimen exhibited were found, and, consequently, it was hoped f; a profitable copper mine might have been opened out; tliis hope was, however, not realised, and the mine was abandoned many years since. The specimen, which -aa cesRtAft.ft. V-

the adventnPcra, is only a portion of the mass aa i nature 1 the miners being compelled to break it to r surface. Fakt or A

The GraaBington mines, the property of tlift Dnke of Devonshire, by whom this fine apttcimen was presented, arc the moat importuit in yorkshirc. This eiample showa in a very inBtructive manner the mode in which, ordiiiariljr, lead occurs in nstnro. By looking at the transverse section, which hanga apon the north side of the stand Bopporting it, it will be seen that the strata in which this lode occurs have been dislocated — that the beds have lost their regn- larity; the result of this being a fissure running nearly vertical throDgh all the beds. In this crock the mineral deposit has taken place, The mineral here formed ia the sulpliide of lead, or galena (p, 106). The regularity observed in the onler in which this fissnre has been filled in with the mineral matter points to a process in nature analogous to that of the electrotype in art; but it would be hasty to conclude, without more evidence than experiment has at present given us, that mineral lodes were entirely due to tho eierciaa of electncol force. Further .remarks upon this point will be found in connexion with the principal collection of lode specimens atpi 97. Tho produce of tho Graasington lead minoB for the year 1OT4 was 1,311 tons 19 . of ore, producing 823 tons 8 cwt. of lead, viik 500 ozs. of sUvcr.

COPPEK Oeb fkom SotrcH AcsiBAm. JTo. 174. .This large specimen, which was presented by the Honourable J. Baker, eshibits a auporflcial coat of malaehite, or green carbonate of copper, encrnating a fine mass of evprite, or red oxide of copper. These minerals are frequently present in the upper part of deposits of copper ore, where atraoaphoric action has penetrated. Tho speci- men before us was obtained from the shallow workings of the Great Korthem Copper Mining Company of South Australia, situated 200 miles north of the famous Buira Burnt mine. At present the principal copper mines of South Australia are worked on Yorke Peninsula, at the head of Spencer Gulf.

Apatite from Canada, o. 168. Some of the most ancient rocks known to the geologist occur in the dominion of Canada, and from their development in the Lauren- tide Hills, north of the River St. Lawrence, have received the name of the Laurentiaii series. This system of rocks ia divided into two groups, the lower of which contains thick bods of crystalline lime- stone, and it ia in this limestone that the mineral called apatite oocnrs. Apatite ia a phosphate of lime, associated with more or less chloride or flaoride of calcium. The Canadian mineral iirequently

E resents a sea-green colour and a cryatalline torture, aa seen in the look before na, which was presented by Moasra. Pickford, Wink- field, and Co. This apecuueu exhibits the apatite in association with avariety of mica known to mineralogists as phlogopite. The Cana- dian apatite is most abundant in the townships of Burgess and Blmsley; the present specimen was obtained from North Burgess Mine, Perth. In eome localities it is so abundant aa to form irregularly-bedded deposits several feet in thickness. The mineral has a high economic value, and workings have been commenced on

.Gold Quabtz. 49

some of the Canadian deposits. By treatment with sulphuric acid it is converted into a soluble superphosphate, which is highly prized by the agriculturist as a fertilizing agent.

By the side of the Canadian phosphate is a fine sample of jpAos- pJiorite (No. 169), or impure phosphate of lime, from Staffel near Limburg, on the Lahn; presented by Messrs. John Taylor and Sons. This mineral is treated in the same way, and applied to the same purpose, as the Canadian apatite.

Portion op a Yein oi GtOLD-beasikq. Quartz. No. 113.

The discovery of gold in California, in June 1848, produced an extraordinary amount of excitement in this country and in thb United States ; within six months 5,000 persons were attracted to this remote region. The gold from the deposits in the beds of the tributaries running into the Sacramento, and in the alluvial valleys of the country, becoming, from the eager search which was made for it, unequal to the desires of the adventurers, the quartz lodes, which were discovered in the rocks, became the objects of explora- tion. Numerous mines were opened, and workings commencea upon an extended scale. In the quartz-veins gold is found, ajid sometimes in considerable quantities; it is exceedingly uncertain. The specimen exhibited is from the Grass valley, Nevada county, and was presented by the late Mr. F. Catherwood : it fairly represents all the average conditions of the gold-bearing quartz-lodes, not only of California, but of Australia and other countries. Small particles of gold are here and there visible, and some gold is disseminated through the mass, but so finely divided as to be invisible. Some richer fragments of gold-quartz are in the same case. (/See Lect/res on Gold, aelwered at the Musetpm of Practical Geology.)

40332.

50 The Staibcase.

F&ZirCZFAL rZiOOB.

The Staircase.

The following objects are placed on the landing at the head of (Jn first flight of steps leading from the ELall to the frincipal Floor: —

Column of Marble from AUport, Derbyshire (p. 30).

Col/wmn of McvrhU from Allport, supporting a vase in Terra-ootU.

Column of Shelly Marble from Stony Middleton, North Derby- shire (p. 30), supporting a vase in Kaolin or China-clay (p. 141).

Vase in Bansome's patent artificial stone (p. 46). Presented by Eansome's Patent Stone Company, 1872.

Column of EncrinUal Marble from Derbyshire (p. 30), snpparting a vase similar to that on the opposite side of the last object, but partially coloured.

Column of Marble from Monyash, Derbyshire (p. 30).

Column of Marble from Nether Haddon, Derbyshire.

On continuing to ascend the staircase which leads to the Principil Floor the visitor will find the following metal castings on the two sides of the steps : —

The Dogs of Ahihiades, cast in iron by Messrs. Moore, Fressange, and Moore.

A Vase, in cast-iron, designed by Edington, of Glasgow.

Candelabrum, in iron, from the French Exhibition of 1846.

CoMdelahra, in iron, cast by Moore, Fressange, and Mooi*e.

Nymph and Sea-horse, cast in iron by M. Durenne.

Eos, a favourite greyhound of H.R.H. the late Prince Consort, life size ; cast in zinc, in imitation of bronze ; the original sculptured by Francis. Oast by Karl Schroder, London. Presented by the VieHUs Montane Company.

Sleeping Dog, cast in iron by Coalbrookdale Company.

Diana attiring, cast in iron by Moore, Fressange, and Moore,

Venus unrobing, cast in iroix by Moore, Fressunge, and Moore.

The visitor on reaching the principal floor will find, at the head of the staircase, the casting of Venus on his right hand, and that of Diana on his left hand.

The numbering of the cases on this floor commences on the right- hand side, close to the casting of Venus.

Synopsis

Of The Collection" Ok This Plooe.

iLLtrsTRATiaiis 01

Uiksral Loses.

pp. 97 to 101.

Colosial Miiterals. -

pp. 101 to 106. 38

In Wall-ottsefl 1 to 14 on W. ade, embracing, CoPPBB, 1 to 7 ; Tin, 8, 8 ; BisstniH, Cobalt, Nickel, and Wolkram, 9; Zinc, 12; Magna- SESB, ITbantum, Titanium, Vakadium, and Cekomiuh, 18 ; Anximoni, Gold, Silver, and Aksenic, 14; and Wall-cases 43 to 66 on E. side, embracing Lead, 43 to 45 ; and Ibos, 46 to 66.

Wall cases on W. aide from 15 to 23. Qrabra<'iug CopPEH, 15 to 17 ; Ihon, 18, 19 ; Manganese, BissnjTH, MoLTBrENUM, Dhanium, Tin, Cobalt, NiQEEi and Anhmosy, 20 ; and Lead, 31; Silver, 22; Gold, Platinum, Mercuhv, and Absenic, S8.

Wall-cases at north end of Muaeuni, on the two sides of Model Boom, 24 to 36.

laes on aide 37 to 42. Australia, 37, East Indies, 88 to 40 ; Canada, 40 to 42; Nova Scotia, New BairHSiTioK, British CoLimiA, and West Indies, 41 ; South Afjuca,

Non-Jietallic Minerals.

pp. 121 to 139.

HETALL17BGY. pp. 110 to 121.

istralian Gold i

on 'vr. Bide.

lee in central arei

Pedestal Case,

Copper Smelting. side, TaTjle-eases 48 and 49 ; and Copper Manufacture, Wall-caaes, 25, 26, 27, and 23.

Tin Smelting. Tablo-caso 48.

Zinc Smelting. Table-case 47.

Brass, German Silter. Arsenic, Cobalt, and Nickel. Table-caae 47.

Leah Smelting. Table-case 52.

SiLVEE and MEacDRY. Table-case 52,

Iron and Steel. Table-cases 50 and 51.

Many other illaatrationa properly inolnded in tho metallnrgioal geriea, will be fonnd in some of the pedestal cases in the central area, nanmly Nos. 4, 6, 7, 8, 10, 12, 14, 18, 21, 42, 43, 44, and 46.

52 Principal Floob.

POTTERY AND Thc ccramic series will be found arranged in

PORCELAIN. the cmbayments on the east and west of the

pp. 140 to 155. stairs. The descriptions commence witii the

raw materials in the lower part of case 57 on

thc right hand or B. side ; then proceed with

Pedestal-cases. 61, 62, 63, 68, and WaH-cases

I. to XXXIX. on both sides of the princiiMd

floor. Foreign pottery, &c. in the lower gaJIery

on both sides.

GLASS, ANCIENT AND Cases in the embayment, at ihe sQniiheTn end

MODEKN. (Nob. 56, 57, 65, 65, 66, 67; and 68). Sheet

pp. 155 to 164. and crown glass in the gallery on the W.

side. ENAMELS. Table-cases 60 and 61, and on the B. side; and

pp. 164, 165. the model of tomb of William de Yalence,

No. 59. MOSAICS. Table-case 54. Specimens on walls of stairs to

pp. 165, 166. galleries.

Central Gases and Models.

Yase in Siberian Aventurine (No. 1) opposite entrance

from Hall - - - . - - - - p. 54

Case op Eussian Steel Work, &c. (No. 2) - - - - 54

Geological Model op London (No. 3) - - - , 54

Model op Puys in Au\'ergne, (No. 41) - - ' 72

Crystallized Slags (No. 4) - - - - - 65

CrystaUiIzed Furnace-products (No. 42) - - - 73

East Side, commencing at End,

South American Agate (No. 5) - - - - p. 56

Ornamental Iron Castings (No. 6) - - - - 56

Manufacture op Swords and Gunbarrels (No. 7) - .. - 67

Illustrations op Physical Properties op Metals (No, -. .58

Manupacturb op Spiegbleisbn, &c. (No. IQi - - " 59

Model op Austrian Salt Mine (No. 11* - - - 60

Illustrations op Swedish Metallurgy (No. 12) - - . 60

Model op Austrian Salt Mine (No. 13) - ,. - - 60

Illustrations op Swedish Metallurgy (No. 14) - - 60

Stone Implements (No. 15) - - - - - 61

Illustrations op the Sub-Wealden Exploration (No. 16) - . 61

Model op part of Isle op Wight (No. 17) - - - 62

Model op Bessemer Steel Works (No. 18) - - . 62

Yase in Fluor-spar (No. 19) - - . 53

At Northern End,

Slab op Bone-breccia prom a French Cave (No. 20) - p. 64

Model op Steel Works at Sheppield (No. 21) - - 64

Water Barometer (No. 22) - - - - - 65

Model op Lead-fume Condenser (No. 23) - - - 65

Model op Cornish Mining District (No. 24) - - 65

West Side, commencing at the N", End, Model showing the Comstock Lode and projected Sutro

TuNiTEL (No. 25) - - - . . - p. 65

Model op Australian Gold Workings (No. 26) - - 66

Model op Part op Alston Moor (No. 27) - - - 66

Model op Landslip at Axmouth (No. 28) - - - 67

Model of Peat Moss in Lanahkshiile (No. 29) - - p. 67

Model of HoucBrsH Mjub, Cosswail (No, 30) - - 68

MoiiEL OP SuayACE-woaKiNGs of a Hewcastlh Coal Pit

(No. 31} - - - ... - . 68

SPECiTLAit Ikon Orb, fkom Ascension (No. 32) - - 68

Gauuja AND oTHEa MiHESAis (No. S3) - - . 69

Gbologicai. Model of Mobi Blanc (No. 34) . . 69

MoOBi. OF Pass op. Mont Cents (No. S5J - - - 69

AusrnALUs Gold (No. 36) - - - - - 69

MoiiBi OF THE Alps (No. 37) 70

ElSCTRO-ltEIAlLUEGY (No. 38) - - - - 7Z

EoEOOHAL LniESTOSE (No. 40) - - - - 72

Oa.NAKENTiL Castuigb (No 43) - - - - 74

Chinese Beonzes (No. 44) 74

Malacuitb and.Amazoh Swwe (No. 45) - - - 75

JlETBOBirES ANB vaMobs Mbtam (No. t6) - - - 75

N.B. — Througliont this Gnide-ljooli the numbers of lie tnble-cases are in

ilalicB, as Cases I, S ; irhilBt tha wftlI-<i>iHeB are intllcaleil b; tlUk,

ognvett, thus, ai. It will Ije Beca, from tto preceding synopsis, that tte Principal Floor of the Musenni containa the miiieralogical, the metaUurgil, and the ceramic Beriee, asBocijited, howovcf, with vajioua niiaael- laneouH ohjocte. The mineralogical serieB is separable into two diTiflions : the metalliferouB, coBtaiaing the ores of onr ordinary metals; and tho non-motalliferons, or, those mmerftis which are either entirely destitute of metal or, &t moat, contain only boo of the lighter and roret metala. The metallio minerals are arranged in the 56 wnJl-caseB aroimd this floor of the HuBenm (p. 79), whilst the non-metaUic minerals are displayed in tte large central case which is known, from its original shape, as the Horse-shoe case (p. 121). This horae-ahoe case enrrotindB the glass roof of the leeture-llieatro below, and formB a prominent object in tho centre of tne room. The metallnrgical aeries ia arranged in the sis flat caaea in the embayments in front of the British metallic minerals (p. 110), bnt the space thus allowed being inanfficient, the metal- lurgical speoimena have crept into several of the adjacent pedestal cases in tne central area. The original intention of those who devised the airaagement — an intention which haa been carried ont wherever practicable — was to e.ifait the ore or raw material in the wall-casefl ; then to show the treatment to which the ore was snbjected, for extraction of metal, in the flat cases immediately in front of tie ores; whilst the applications of the metals in the arts would bo iUustrated by Bpecimena in the podeBtal caaes in front of the metallurgical collection. Thus the oree tif copper ara eixhibitcd in Wall-cases l, Z, 3, ft, Ao. ; the raetallnrgy of copper is ropresontcd in the Flat case No. 47 in front of these wall-cases ; and finally the casting of eopMr and its alloya ia illustrated bjr statnettea in the Pedestal-caae JNO. 43, which again is immediately in front of No. 47, The ceramic and vitreoaB aeries is separated aa far as possible from tho otter collBCtlona on tbia 'floor, and forms a compact group of iibjectfl at the Bonthem end of the room (p. 140). In addition, how- ever, to these Bystematic collections thei'e are enhibited in this gallery a large nnmber of models and miaeellancouB objecta; and ea some of these are likely to arrest the attention of the visitor as soon ae he reaches this floor by the ataira leadinj from the Hall, it ."Y he desirable to commence oar Burvey by dcBcribmg 'liia "AJvaifta -*iii<si- iril) be /bund in tie central area.

The Pbihcipal Ploob.

CENTRAL CASES AND MODELS. No. 1.-

Thia handHOme vase was preientod in 1843 hj the late Emperar of Saeaia, Nicholas I., to Sir R. I. MnTchiaon in recogrution of hu eervicea in esploring tbo geology_ of part of the RnBaian Kmie. The material of the vase is a micaceona qiiartii-rock, passing mto atcjiturino (p, 132). Tho flakes of mica aro arranged in irregnlM banda running obliquely acroaa the oviform body of tho vaae, whilst the whitish colonr of the atone ia relieTod by iron-stained patches, of brown and yellow tints. A mottled pink variety of qattrtz-rook forms the baeo of the vaeo, which ia distinct from the body ; and the whole is aupported on a handaame pedestal of groy porphyittdo rock. The materials of both vase and pedestal were obtained, from the hills of Bieloretek and Korgon, a dependence of the AHat Monntaina, and were polished in the Government of Tomsk. Tha vase ia fonr feet in height, and measures six feet in cironmfeKaiOB at ite largest port. So great was the difficulty of obtaining blocki of this size, and of poliahiug such hard materials, that it is believed only one aimiW vaao was ever made i this was presented by tha Emperor Nicholas to Baron Humboldt, and is now in the Boyat Museum, at Berlin.

A small table-case, standing immediately behind the Siberian vase, contains some intoreeting objects bequeathed to the MnsoTim by the late Director. One of these is an ornamental steel plateau, or salver, manufactured at Zlataust in the Ural Mountains. This town, which baa been called " tbe Birmingham and Sheffield of the Ural," is situated on the banks of the Eiver Ai, in a romantic valley on the wSBtem side of the watershed of the tral. A view of the locality adorns the centre of the plateau. Under General Anosoff, tho Imperial Steel Works of Zlatanst attained great celebrity for the manufactm'e of sword blades. " It may he doubted," said Captain James Abbot, " whether any fabric in the world can compete with that gf Zlatanst in the production of weapons combining, in an equal degree, edge and elaaticity."

The plateau is ornamented with a border representing allsgoricalW' the manufacture of a sword, and some examples of the actu swo will bo found in Pedestal-case No. 7. The plateau is formed of humiahed steel richly ornamented with gilt damascene work, and hears an inscription in Euas, which has been thus translated; —

" To the geologist R. Murchison, in testimony of its partionlar esteem, the Administration of Mines in Eassia, Zlatauat, 1843."

Another prominent object in this case is a gold snn£F-bos, set with a largo number of diamonds, and ornamented with an enamel poi-trait of the Emperor of Russia, Alesander II. This box was presented to Sir R. 1. Murchison by the late Emperor Nicholne.

No. S, — Geological Model o? Loitdon. This large mode! was constructed by Mr. T. B, Jordan, under the superintendence of Mr. W. Whitaker, of the Geological Survey. It represents a tract of country around the metropolis as a centre, measuring about 15 miles from east to west, and about 1] miles from north to south; or a total ai'ca of something like 165 square

' Central Cases. 55

mileH. Tlio horizontal scale is the eame aa that of the conntT maps of the Ordnance Snrvey, namely' si\ inches to the mile ; whilst the vertical Bcale is 200 feet to the inch, or ahout 4"4 times as great as the former. Had the vertical scale been the same as the horizontal, OS was originally intended, the heights on the mode! would have been so rnsigniflcant, that the highest point which it incindes, the top of Eampstead Heath, would have been represented by a rise of little more than half an inch. An exaggerated vertical Bcale waa therefore absolutely necessary in order to exhibit with due cfi'eet the nndulationa of the ground. It will bo observed that although the area around the metropolis is popularly known as the " London Baain," this baain is in fact nothing more than an extremely shallow . depression ; and even with the exaggerated dip reprefented in the model, the beds slope towards the centre of the trongh at a very slight inclination.

The oldest rock which comes to the surface within the area of the model is the chalk ; but some of the deep wells sunk in the London basin have reached the underlying rocks. the fam.ouB boring at Kentish Town pierced the Chalk, the Upper Greensand, and the Gault ; and then entered older rocka the geological age of which is extremely donbtfal. The beda below the chalk are seen in section on the sides of the model. In fact the model ia conatroeted in nine separate blocks, five of which can he' raised by means of a winch so as to expose the sections on their inner sidee,*

By far the greater part of the coantry represented in this model ia formed of rocka overlying the chalk and belonging to the tertiary series. These consist of the Thonet bods, immediately above the chalk ; followed hy the "Woolwich -and- Beading aeries, the Oldhaven beds, and the London Clay. This clay ia about 400 feet in thickness under the Metropolis, and ia covered on the hills of Hanipstead and High- gate hy sandy beds known as the Bsgshot Sands. No deposits of more recent age occur in this area, until we reach the post-tertiary gravela, sands, clays, brickearth, &c., which are grouped together under the general name of Drift. A system of colouring exhibits the distribution of the several formations, inoluding these superficial depoaita. For further iidbrmation the visitor should consult the Gukh to the Geology of London, written by Mr. Whitaker in expla- nation of this model and of the Geological-Survey Map of London and its e:

Wo. 4.Case ot Cktstallized Slags. A small table-case near the iron casting of Venus, at the head of the staircase, contains an interesting collection of slags, or fusible silicates produced in varions metallurgical operations. Many of these, exhibiting beautiful crystalline forma, were examined by Dr. Percy and Professor "W. H. Miller, who, in 1846, reported to the British Association the results of their inquiry. The production, ujider the peculiar circumstances in which these slags were formed, of crystalline compotmda, in many respects similar to aome which are found in nature as minerals, renders the inquiry into their chemical constitution and physical conditions a peculiarly inte- resting one ; and in its bearings upon many geological phenomena it is most especially so, aa showing the influences of the long-con- tinned action of high temperature upon mineral combinations and crystalline structure. Among the specimens may be observed some

Viaitora desirous of inspeetiog Ihe sections on the sidea of the moveable , should apply to the officers of the Musfcvntitot eratiftiwm. ttoss. them, bat should not otherwise attempt to dl&luib &e taoanX.

J

S6 THE. FEthrciFAL iXOOB.

eiamplea of the cnriona liair-Uke ltg occasionally obtained from blaat-famaceB. This is produced by the from the twrera catchinz the slog, and draining it out into Sno fibires, like spun wbi A aimilar natural product from the Sandwich lalands ia known m " I'fUe hftir," (see p. 136). For information on the contents of (his CBae generally the ™itor may consult the first rolnme of Dr. Pctoj'* Metallurgy.

No. 5. — Agate.

A fine polished specimen of agate standB on a pedestal near the model of London. S'eaily all the agates which arc brought into commerce are obtained from Uruguay, in South America, whence ' they are exported to Germany, and are out and polished in the neighbourhood of Oberatein, on the Eiver Nahe, a tributary to the Bhme, The district around Obergtein and Idar has become fuuouf for its agate- works, but the atones themselves are no longer bbtunied, as they formerly were, from the Burrounding hills, (See p. 133.) No. 6. — OayAMEMAL Ihos Castikss. ' "

Some fine examples of the use of iron in art manufacture, and for the reproduction, in durable material, of works of high art, arc here exhibited. Such productions are coloured either by the application of a resinous paint or by a process of bronzing, whicB may be effected by the application of Alorule of 2>hii>i'um, of the aalU of copjicr and iron, and by other means, one of these bein the deposition of thin coats of copper or brass by the elootrotypa process.

Berlin, Cast Iron. — Some beautifiil specimens of the delicate iron castings of Prusaiii aro in this case. At the time when the P tbI stniEgle conmienced between Prussia and Napoleon, the patriotism of the Prussian ladies was pai'tieularly conspicuous. With the noblest generosity they sent their jewels and trinkets to the Boyal Treasury, to assist in fornishing fimds for the erpenaes of the campaign, Eings, crossea, and other ornaments of cast iron were given in return to all who made this sacrifice. They bora the iuscription, Gold fUr EUeu (gold for iron). Such Bpartau jewels are, to this day, much treasured by the possessors and their; families. [SaniUiook of Nortliorn Ga-mawj.) This led to the

E redaction of ornaments far more delicate than anything which" ad heretofore been mimufactnred ; and these becoming known and admired in every part of Europe, an extensive trade in them speedily arose, and has been maintained.

The Castings intended for use in, Boo'kUn<ling, the Cast Iron Fan, Necklace, aiMi St'ohta, from the iron workB of the Count Stolberg-Wemigerode, at Usenburg, Hartz Mountains (Magdeburg), are fine examples of this manufacture.

The large circular ornamental casting, with the sand attached, aa it was taken from the mould, shows the perfection to which the processes have been brought. It has been thought that much of the boauty of these castings depends upon the sand employed in,

' ing the moulds. Hence the sand collected about this casting,

i.._ii 1 — "ntho metallurgical laboratory, Itwas

Silica - . . . 79'02

AInmina - - - 1372

Protoxide of iron - - 2,10

Lime - - - - trace

Magnesia - - - 0'71

Potash - - - - 4-58

WIiitiEOrfh's Seretca and Flai'X may be remrded as perfect examples of the prodnction of trne surfacea. When the two ii'on planes are brought together the upper one oate on a film of eir, and when this ia pressed out the coheairQ force of the two BurfaceB iaverypreat; this may be regarded aa proof of the correctness with which these surfaces have been formed.

The screws and the gangos were proparod with a view to Uie introduction of a Bystem of standard screws and gangea.

No, 7. — Swords ab GuN-BAHBEts.

. — Tie oriental sword blades have always been celebratedv and their superiM' chamoter hfta been stated to, and probably does, belong to tho very excellenS iron ores whirh are obtained in varions parts of Asia, and to the redaction of those ores by charcoal. Sworda And daggers (rom the Punjab, Igpaban, and Borneo are in jaxta,- position with apeoimens of the DaraoscoB, Andrea Ferrara, and Toledo blades.

The finest oriental salwcB are those, professedly of great antiquity, preBumed to have been made at Damascus in Syria, Ispahan in Per- sia, and at Cairo in Egypt. The characteristics aecribed to the real Damascaa blades are, esiraordinary keenness of edge, great flexi- bility of substance, a singular grain of flectinoss always observable on the sui'face, and a peculiar musky odour given out by any friction of the blade, either by bending or otberwiae.

Milan, Bilboa, and Toledo furnished the Crosadere with Iheir Words, Milan appearing to have been the great mart for the sale of both the Spanish, and the ItaJian weapons.

Toledo ander the fiomans, and in the time of the Moors, was oele- bratod for the admirable temper of its swords, " which is chiefly attributable," says a writer oil the Toledo blades, " to some favoor- able quality in the water of the Tagns, nsad in temperino; the steel." The swords mannfaotured on the banks of the Guadalq-nivor ore said to be very inferior, from this cause, to those made by tho same workmen on tlie banks of the Tagns.

Andrew of I'errara has associated his name with the swords of his manufacture, "Andrea FeiTara." Tlii? sword makerwos conaidered, in his time, to be tJic only man in Great Britain who knew how to temper a sworf in ffoch a way that the point should bend to tonch the hilt and spring back aRain nuinjnred. Ho is sid to have resided in the Highlands of Scotland, where he employed many men in forging his swords, devoting his entire attention to tempering them. This operation he performed in a dai-k cellar, the better to enable him to distinguish tho colours produced by heat oil the blade, upon which everything depended.

Swords appear to have been made at Birminiam from a very early period : Hutton, the local hiatorian, iiays, long before the landing of Caesar. Sword making is, howeycr, now one of the staple trades of Birmingham ; tte forges of Shef&eld, hfnvover, for- nish a large quantity of bars of steol, called giaord -niovMa, One of these is shown, aa also tho fiistening of the lanrj, which ia of iron ; and the resnlta after the different stages of forging. It is hardened by heating it until it becomes womi, r<id, and then dip-

eing it, point downwards, in a tub of cold water. It ia tempered y drawing it through the fire several times, until it esbibita a bluish oiidation on the surface. It ia subsequently polished and mounted.

MoAwfaature of &(i!>irt)Teis.— The principal object in the manu- facture of a guu-barrel ia its strength. 1\, abovii Vs.w -Ki.-Q.ei

58 The Principal Flooe.

tenacity as wiU enBiirc ils rcsiatiDg the enddon shock to which it ia eiposed in projecting the b&U by the exploaive force of gnnpowder. Experience has prored that thia is obtained by the nae of iron which has undergone peoniiar processes of mtmofaotiire, Scrap iron ia employed for inferior bairelB, horse-shoe vaiU and serop *Uel are taken for superior kinds ; these are welded into flat bars ; the bars of iron and steel are again wtlded together, and formed into square bare. If a nnmber of etraigbt bars were welded together to form EJ barrel, they woald be liable to open along the lines of weld- ing ; at all eventa, such a gun-barrel would not bo nearly so safe u one made of tbo same boxa formed into a helix, and tnoa welded into a tabe, Theao two conditions are shown in the specimena in the caeo.

By altering the arrangement of the fibres of the iron, iheste is produced a different pattern on the anrfaoe of the barrel when thej are tendered Tisible liy poliahing. Thus one bar is twisted to the right, another is twiatcd to the left hand. Now these when twisted on a mandril are welded into a barrel, which will exhibit an in- volved pftttem. If they aro combined, or if an untwisted bar is placeil between thorn, and they are then turned and welded, we have a still more elaborate pattern as the roanlt. the gnn- Bmith possBBsea the power of varying estonaivoly the patterns npon the barrel.

From the welding-ehop the barrel paaaes to a workman who dnly examinea its soundness, and, if it is required, straightens it. The barrel is then tranaferred to the boring mill, and pro- perly ground ; it pasaea ihrongh a subsequent prooesa of fine boring- The exterior of the barrel ia ground by the grindstone, and then filed with a smooth file and flnished ; those last opera- tions are commonly performed by women. Bairela are browned by the application of a combination of iron and copper in nitric acid, to which either spirits of wine or sweet epirita of nitre have been added-

The lower part of thia eaae is occupied by some very fine examples of Bessemer steel from the International Exhibition of 1863, presented by Mr. Bessemer.

jjo. 8. — Illtjstbations or the Physicai Phopebtieh of Metals.

A collection of specimens is here exhibited to illnstrata the

Shysical properties of metala, especially theii- malleability and uctility, and to show the advantage which is taken of such pro- perties in applying metals to porposea of ornament. Malleability ia the proper of permanently extending without fracture when the Huhstance is subjected to pressure, as in rolling, or to impact, as in hammering. The great malleability of copper is well shown by a penny-piece rolled out to a length of ten yards. Excellent illustra- tions of the malleability of copper are also fumiahed by Messrs. Tylor's seriea showing the auccesaive stages in the manufacture of a vase by hammering it into shape from a flat sheet. The largo central ewer, of French manufacture, in the atyle of the Italian i renaissance, shows how copper admita of being beaten up ; and there are likewiae examples of repoiwsiS'work in ailver. Speoimena arealso exhibited of copper sheathing, rolled zinc, sheet cadmium, " paper iron," gold leaf, and various foils. It is found that in the process of rolling or of hammering, the metal nnder treatment is apt to lose its ' malleabihty and acquire brittleness ; in order, therefore, to restore its malleability it ia necessary to anneal the metal by espoaure to ,

CENTRAI/ CABia. 59

Ductility, or the property of permanently extending, witbont rapture, when the BubstancG ia anbjected to a polling force, aa in wire-drawing, is a property closely conueoted with malleability. Some examples of gilt silver wire, contribated by Messrs. F. andB. Btanton, are interesting aa ehowing the great extenaion of which gold and silver are capable. In one example 10 . of metal, con- siating of 2 graina of nne gold, ooyering 238 graina of ailver, were drawn to the length of 1£24 yards ; the thickness of this silver wire will therefore be 0093115 jnoh, whilst that of the overlying gold will be orly 0000216 of an inch. Yet, even these limits, striking as they appear, may be eioeeded in wire-drawing.

There are also in this case several coina and medals, ahowlng the shnrpness with which certain metala receive impressions when stamped. The process of Bllver-jihtinq is likewise illuatrated here. The art of overlaying one metal with another of a more valuable character is of great antiquity ; but, aa far aa we can judge, the application of the more expenaive metal upon the inferior one was ' originally merely some method of washing or gilding, or of affixing sheets and foils by means of some adhesive material.

The proceaa of "fire-plating," so called to distinguish it from the electro-plating, appears to have been first employed in the metropolia. The method ia as follows : —

An ingot of copper as ahown, or of copper containing a little brass, ia prepared after casting, by filing a perfectly smooth and clean face, which is afterwards carefully scraped; on this a plate of silver, alao perfectly amooth and clean, being a little leas in size than the copper, is placed so that the bright Burfatiea shall be in contact. Over the silver is placed a piece of sheet iron of the aame aize, brushed over with whiting to prevent its adherence to the mass when heated. The iron, ailver, and the copper iogot are bound together by means of Bmail iron binding wire; a little boras ground with water is laid around the silver iu the apace where its edge approaohea that of the copper, after which it is ready for the fire. A perfectly clear coke Ere being obtained in a small rever- beratory fnmaae, the mass is placed in it, and allowed to rem.ain until aymptoms of f'aaion appear upon the edges of the silver, it is then immediately withdrawn and allowed to cool. If the right time ifi secured for withdrawing the copper, the silver will be found to have adhered perfectly over every part, and the mass may be sub- mitted to rolling and the proceaaea of manufacture, the silver uniformly extending with the copper. This ia illuatrated by the ingot and the sheet in this ease. The proceaa of plating ateel bladea for dessert knivea is alao shown. Por electroplating, aee p. 71.

So. 9. — Head Melpomene, after the antique, electroti/ped and pj-e- senled by Messrs. ElMitgtoii Co. At foot of eastern staircase to Gallery. For description of the art of electro-metallurgy, ace p, 71,

ITo. 10. — MiMCFACTUKE OF SpiEGELKISBN, Ac.

One half of the table-ease near the electrotype of Melpomene is devoted to illustrations of the mannfactore of Spiegeleison, mostly presented by Mr. H. Bauerman, Spiegeleisen is a highly crystalline variety of white cast-iron, rich in carbon and manganeae, and ex- hibiting on fracture brilhaat mirror-like cleavage -p lanes. Of late yeara its manufacture has acquired considerable importance from vta nse in the Bessemer process of steel TuaVang. "V.evi. cwnOoaa

SO THEl nUNCIFAL WVQOB.

been completely romovod from tha oast-iron in thAt process, & proper qoODtity of spiegeleisen is introduced into the Beasemcr couTortor, and thuH the required proportion of carbon can bo added witii great , precision. The apiegeleieon is largely eroclted from the epothn; iron ores, or carbonnte of iron, of thJa Siagrai district in 'Weatjihalia, and is ako ntanofoctarod &om similar ores in Stjria ; whilst m Ijua ooiintiy snitablo msterials ars fomishod Ijy tho spathose ores of the Eimoor hilla in Devonshire, the Brendou biUa in tiomerBetahire, and Weardale in Durham. Spieleiaen ia also obtained in some of the Continental vorks from manganesiferous hematites, and it is lik&- wise smelted &om the residaes obtained in the treatnioat of miied ores of iron and zinc at Newaric in New Jersey. The latter pro- cess ia well illustrated in the case before us. After the greater part of the aino has been removed from the ore, the cinder-like residae ia smelted for Bpiecolein. This residue contains all the iron aud manganese originall; present in the Frouklinite, one of the chief minerals in the mixed ore. The bright green colour of the slag aoci>mpanj'ing the spiegeleiaeti due to the presence of maDgaoese. Tlio proportion of manganese iu the apiegeleiaen varies considenibly in different epecimeus ; one example exhibited, from Xiaibaclt in Camiola, oontains as mueh as 14 [lercent. But even this proportion is far exceeded in the alloy known as fsrro-manganese, one speoimen of which, in the case before as, coatains not less than 33 per cent. This alloy ia used for the same purposefl aa apiegeleiaen.

On the oppoaite aide of this case will be found n series of specimens illuatrating the emoltiug of the brown iron ores of the Coral Bag — one of the sub-divisions of the series of middle oolites — aa carried (at at Westbury in "Wilts.

A portion of this caae ia temporarily oacupied by specimeus show- itig the powerful agglutinating action of oside of iron.

Nos. 11 and 13.— Mobels op the Salt Misbs of HaUein awi Kaltstadt, in {lie Saldniiy Alps.

The mines here repreaented are opened in depoeits of veiy irregular form belonging to the secondary series, in which the rock salt is mingled with clay and gypsum. The principle of working is to introduce fresh water into eKcavationa prepared for the purpose, where it gradually dissolves the salt, lea7iiig the clay and gypsum behind, the solvent action being exerted chiefly on the roor of the chamber ; the brine is then conducted by lower galleries to the out- side of the mountain, and runa in pipes to the spot where the evaporation works are situated. A third model, representing the salt mines of Aussee, will be found in the upper gallery.

Nos. 12 and U. — Swedish Ibon akd Steel, 'Copper, &c. It ia well known that iron of a very superior quality, much valued for steel mnnnfactnre, lias long been produced from the iron ores' of Sweden. These conaist chiefly of the magnetic and red oxides, which are olasaed together as " monntain ores," to distinguish them from the brown, oxides, which occur in the shape of laJie and bog-ores, and yield an inferior kind of ii-on employed chiefly for castings. The mountain-ores are oaloinod usually m kilns boated by the waste gases from the blast furnace, and are ameltcd esolnaively ' with charcoal. It ia to the employment of this fuel, and to the free- dom of the ores from phoaphoms, that the Swedish iron owes its superiority. The greater part of the pig iron is converted into malleable iron in refineries, or hearths, heated with charcoal. At,

Bs*

GHHTWAZ eiSlS, 61

ova, the ancient Walloon process la Btill employed, but at most otiier works it haa l)een dispiaced by the ao-ealled "' Lftnoftabii-e method," introdnced from South Wales. In aome of the Swedish works paddling is practised to a certain estent, and the Beaaemflr process has alao been introdnced.

The table-case No. 12 is entirely devoted to apeoimens of Swedish ii'on and steel, and a large part of No. 14 alao contains esatnpleB of these metals and of the ores from which they aro prodnced. Bat the visiter will also find in H"o. 34 a number of other Swedish metallur- gical prodnota, including a seriel illustrating the cstraction of nickel at Klefva in SmIIand ; the smelting of lead at Sala and the prodnc- tion of copper at Falun. Tho mines, or rather open workmgfl, at Falnn, iuDalecorlia.are of great antiquity, and yield large quantities of copper and iron-pyrites, but tho workings are of much leas import- ance now than they were fbcmerly. The ores aro but poor, and yield when dressed more than about 4 per Cent, of metal.

No. 15.— Stone Implements,

Associated with the bones of many of the eitdnct mammalia of the post-pleioceno era there have been fotmd within tho last few years "Teat numbers of flint implements, bearing undoubted proofs of human workmanahip. The French antiquary, M. Boucher de Perthoa, was the first to direct attention to the occurrence of flint "hatchets" at considerable depths in the sands and gravels of the valley of the Somme. Some of these worked fliuts from Abbeville and Amiens are here exhibited, and with them are other flint implements from widely separated localities. These rudely chipped , occurring in the drift-gravols, are to ho distingaished from tho more highly finished eclis, which, in m.oet cases, bear evidence of having heou carefully ground and polished! stone weapons, by no means always of flint, are much mora recent than the worked fliuts from tho drift, being preferablo to that pre-historio era, known to archiBO- logista as the polished or newer Btone age. Tho former are known na paiaioHthie, the latter as TieoUth forms.

For compariaou with these anoient flints and celts, and to explain their probable use, there are exhibited, in the opposite compartment of ths case, several examples of the rnde stone implements used by certain savage tribes at the present day. A few flint arrow-heods, prepared to deceive collectors, arc abo placed by the side of the genuine relics.

Those visitors who desire to study in greater detail the relics of the "stone ages" maybe referred to the splendid collection be- ijueathed to the nation by the late Mr. H". Ohj-isty, and exhibited under the care of Mr. A. W. Franks, F.E.S., at No. 103, Yictoria Street, Westminster.

No, 16. — iLLcsTBiEOss OF THE Sdb-Weaides Exploeaiiok. On the occasion of the meeting of the British Association at Brighton in 1872, a bold geological experiment was projected by Mr. Henry Willett. The experiment conaisted in an attranpt to ascertain the thickness and the order of enccession of the several secondary rocks beneath the Wealden area in SuBses. For some years the notion had had been gaining onnd among geologists that these secondary rooks were comparatively thin in the aouth-east of England, and that some 6f them might be altogether absent, so that the older or paliBoaoic rocks would probably be found within a moderate depth. If the palseozoic rocks were thus acoesaihle \t-a.s cViiaA SRKWsl

62 Th Pbincipal Plooh,

tliat tbeyiaigbt inclnde productive coal-ineaiinreB, and hence a notion cot abroad that thia ei[rimeiit waa really a search for coal in SnHBOia notion entirely ansnpported by nien of science. The sito finally selected for the enterprise waa in the pariah of Netherfiald near Battle. After the boring had reached a depth of 1,030 feet pome accident led to the abandonment of this hole, and a new boring was commenced with diamond'tnounted drilla, on an adjacent epot. The second boring, begun in Pebrnary 1875, attained a depm of nearly 2,000 feet, when it woe found necessa to eaapeud the irork- ing for lack of fondfl. Major Bcanmont, M.P., ia however, now seeking to reaume the boring, and hae been supported by the British Aeaociation.

The case before ns contaiua a model of the Wealden area, hj Ur, W. Topley and Mr. J. E. Jordan. In this model the geograpliicol structure of the Weald and the position of the boring are clewly shown. There are also a number of solid cores of rock drilled out l? the boring tools ; some of these were extracted by the old-foshiooed tools employed at the commencement of the work, but moat of liem were obtained by the diamond-mounted drills. Some of these eteel crowns, set with rough black diamond or carbonado (p. 123), are hem enhibited; whiiat the machinery employed at the anrface ia repre- sented in the accompanying photographs. The boringa were com- menced in the Pnrbeck aenea, and valuable beds of gypHnm (p. 43) werediscoveredat a moderate depth J this mineral is now worked com mercially at Nethorfield, and aeyeral large cores of gypsum will seen in the lower compartment of the case. A great thickness o: Kimeridgc clay was penetrated, much of which waa found to he highly fDaailiferoiis, and many of these foaaita are exhibited as they were fonnd embedded in the cores of shale. Below the Kimei-idge clay the borers reached beds of doubtfnl geological age, probably either Osford clay or representatives of the Coralline Oolites. Our know- ledge of the thicknesa and snccesaion of some of the Snb-Wealden secondary rooka haa thna been conaiderably extended by this esplora- tion ; and although palteozoio rocks have not been reached, it must be admitted that the original object of the experiment haa been fnUy attained.

No. 17.— Model op a Portion op ijie U"HiiEKCLi?y, Isle ob Wight, by Capi. SoBcaivem Ibbeteon, K.M.H. Thia model represents a portion of the aouth aide of the lale of Wight, extending fiijm Bouchnrch to Sandown Bay. The chalk, which stretches acrosa the island from east to west, forming the downs or undulating tracts of high ground, ia seen to rest imme- diately upon the upper greeneand, which is separated from the , lower greensand by a band of ganlt. The upper greensand slipping over the surface of the ganlt clay haa given rise to the romantio scenery of the Underciiff. For further informaiion, see "The Geology of the Isle of Wight," by H. W. Bristow, F.R.S., published in the " Memoirs of the Geological Survey."

ISfo, 18. — Model Illustratino Masutactl'ke op Bessemeh Steel.

The process of making the celebrated Beaaemer steel ia well illustrated in thia model, which waa conatraotod by Mr. T. B. Jordan from drawings_ fumiahed by Mr. Bessemei-. Caat-iron suitable for conversion into steel by thia process ia smelted from Cnmberland hiematite (p. 106), or from other ores nearly free from phosphoms. The iron having been melted ia run through a gutter

into the " couveTter," where it ie espoBed to the oxidising actioa of EL blast of atmospheric air. The converters, mtirked AA in the model, Rre coniitruoted of wronght-iron plates riveted together and lined with fire-clay, ganister, or other refractory materials, A sectional model in the lower part of Che case ehowa the conatmo lion of these vessels. Two three-ton converters are represented in the model ; one in a horizontal, the other in a vertieal position. Each vessel is Bnspendod upon two trunnions, and can be rotated by means of a doublc-aictitig water~pressure engine, the piston- rod of which carries a rack gearing into the pinion on one of the trunnions. While the metal ia rnnning in, the converter is hori- zontal, but when charged it is slowly swung into an upright position, and air is then blown into the molten metal through twyers in the bottom of the converter. One of the fire-clay twyers is e.thibited in the case below. The blast is produced by blowing- engines FF, worked by Bteam cylinders attached j and the air reaches the vessel by passing np one of the tmnnions which is hollow. On admission of air the carbon and silicon are rapidlr OKidised, and a flame iesues from the month of the converter fol- lowed by brilliant showers of sparks. When the last trace of carbon has been removed, as indicated by changes in the character of the flame, the converter ia tilted back into a horizontal posi- tion, and a due quantity of molten spiegeleisen (p. 59) is ran in. The precise proportion of carbon required to form steel is thus Bupphed to the iron, which has been completely decarburiaed by the blast, and the melteil steel ia then poured from the convei'ter into a large ladle. This ladle is carried at one estremity of a moveabls

CformC, which is caused to traverse the casting-pit by means of a die connected with spur-gearing. The ladle is a large wrought- iron vessel lined with fire-clay, and having a hole at the bottom for running the metal off into the moulds. A series of these cast-iron moulds is placed round the floor of the casting-pit, and several steel ingots are also represented. The ladle is carried round until the hole is directly over one of the moulds, when the plug which closes the aperture is lifted a lover, and the metal escapes. The ingots are lilted from the casting-pit by means of the hydrtiuUc cranes DD. At E is a set of hydraulic pumps fpr supplying the water-pressure which moves the converters and the cranes ; whilst the working of the whole apparatus is regulated by the gearing represented at B.

Some fine examples of steel manufaotui'ed by this process, and presented by Mr. Bessemer, are distributed over the vacant space on the floor of the model, and others ore exhibited in the lower compartment of this case and of case 7.

No. 19.— Large Vase os Fluoh Spas. — Fresmled by S. Addimloa, Esq., F.S.A.

This handsome vase is formed of a beautiful variety of Fluor spar, which occurs only at a single bill called Tre-clift', near Castleton in Derbyshire. It is a mineral of flnely-variegated pmple tints, known locally aa " Blue John," a naoae adopted by the Derbyshire miners to distinguish it from " Black Jack, or zinc blende {p. 83). The Derbyshire spar was not known until the year 1T70, but it has since been so largely employed for ornamental parpoaes that the true "Dine John is no longer to be obtained. The spar rarely occurred in masses of large size, and hence the diflicnlty of pro- curing material fur mannfaottring bo large a vase as that exhibited. This vase, which is constructed of several pieces, is 2 ft. 8 ins. high,

P-T

THE-TimreWAt VLdOEt.

)

and its grentcst circninference is about 3 It. 7 inghes. It was madfl bj Sir. vallasce, of Hattock, and it is believed that it is exceeded in size and beanty by only one other vaaa of flnor-apar, -whicli it in the pofseesion of the Dake of Devonshire at ChatBworth- f (9 a mineralogieal deacription of flnor-apar, see p, 131.

So. 20. — Slab fkom the Bone-Catkrs or Les Eyzies. — Preaenteihg the late M. Lartei and S. CWUtij, Egq.

This slab of osaeous breccia was obtained, hy the donors, from the floor of the bone cavern of Lbh Eyzies, in the valley of the Beune, a tributary to tho Te'etre, iii Dordogne. The bones are chiefly tbosi of the reindeer, and are in niOBt cases fractured, having probably been brokeu for tho extraction of tho marrow. These bones wa ftBaociated with great?* nnmbers of woriced flints, rolled pebbles and ftagmonts of foreign rooks, the whole being cemented togethOT ly atalagmitic carbonate of lime. The moat intereating relics of hnniail workmanship in these deposits are rudely-engraved pieces of b(ra6 and plates of achiatoso rock, which are undoubtedly the earlies* known specimens of the engraver's art. In the block Ijeforo na there has been fonnd a email bone needle, and a huinan tooth wae detected in a similar slab aont to Vienna. '

The bone deposits of Dordogne are referable to a remote er when the uae of metal was apparently unknown, — an era pofilorior to that of the mammoth, and characteriaed by the presence of the rein' deer in certain southern diatricta where it has not been foand during the histoiie period. Por information on the French bone-oaves tlia visitor Boul'd i-efer to Meaai's. Lartet and Christy's BeluiKuB Aqvti iawicee, edited by Professor T. Rupert Jonea, 1875. J

No. 21. — MoBEL OF Steel "Wouks 4t SnEniECD. — PreaerOailiy Messre. Naq/lor. Viekerg, and Co., Sheold.

Whilst the modem procesB of making Bessemer ateel ia illuBtrated by the large model. No. 18, the older process of producing steel by what is called " cementation " is well shown in the mode) before us. The Bicel ia in this case produced from the malleable iron by oausing the metal to take op adintional carbon, but not, howerer, in sofBoiKit quantity to form cnatiron ; tho result of this process of conTersioii is known as cement steel, or blister steel. Bars of malleable iron are imbedded in coarsely-powdered obarcoal in large boxes, and espased for a long time to a fall red heat. To prevent the charcoal &om burning away, and to confine its action as much as possible to the iron, the whole is covered with sand or earth which will not easily vitriiy. In Sheffield a stiff ferruginoua mad, called lalieeU- iBkarf,—th.B staff which is produced by the wearing of the grind- stones, — is generally used. Every imneecBsary aperture is care- fully closed. The ohest containing tho iron and charcoal, which holds from 13 to 17 tons of metal, is then exposed in the converting furnace to the action of fire, which is maintained at a high intensity for several days, when the bars of iron will be found to hare taken, up carbon and to be conyerted into steel. The theory of this prooess or conyersion whereby the carbon of the charcoal combines with the iron is far front clear.

This model represents the arrangements also for melting and coating ateel, and for rolling it into bars, &c. Specimens of steel are exhibited in case 51 (p. 120), and a collection of ateel will be found on the walls of the Model Koom.

CESTRir, CASK,- 65

No. 22,Watee BAEOnrTEK.

ThiB inatrnment will be found at the northern end of the room, near Wan-caBe 29. From the ordinary mercurial barometer it diflbi'H only in the snbatitution of a column of water for one of qnickailvor ; Ijut since water is, bulk for bulk, about l-'Ji times lighter than quicksilver, it ia obviona that the column of water neceasary to counterbalance tbe atmoanherio prenartre be 13} timee longer than that ased in our ordinary instruments ; thaa, while the moan - height of the mercurial barometer ia about 30 inches, that of the water barometer will be upwards of .13 feet. Apart from other objections, the manifest inconvenience of so nnwieldly an inatrn- m.ent forbids its general adoption, hut the extreme aenaibility of ita indications givee it considerable acieutific intevcat; the column of water being eensibly affected by variationa in aerial presanro too slight to produce any perceptible effect on the mercurial barometer. The indications are, however, seriously affected by the pressure of the water vapour which escapes into the apace above the column.

Some years back, an instrument similar in principle to the one before ns, but different in conatruction, was erected by the late Pro- fessor Boniell, in the Royal Society'a Hall. In the instrument here eidiibited, which was conatrnoted by Mr. J. B. Jordan, the glass tube forming the upper part of the barometer ia alone expoaed, the metal tubing oonstitnting the lower portion being carried downwards to the basement ot the building, where it terminates ill a ciatem of water, the surface of which ia covered with a stratnra of mineral oil to prevent evaporation of the liquid and absorption of air. Mr. Joimn has since succesafnlly constructed glycerine barometfira, which have the advantage of affording more accurate readiogs, aince the glycerine gives off vapour of low tension which does not deflreaa the fluid column to the same extent as the aqueous vapour does in the water barometer.

No. 23. — Model or Lead-yitme Oondbbber at Warlock Head WonKs, The fumes are conveyed from the fluea into a double- chamherc J condenaer, where the lead is separated by pitssing through showera of water ; the purified smoke oacaping through a tall chimney, while the water is collected in a reservoir where the lead is depo- sited. It is employed at the Duke of Buooleugh'a lead works at Wonlockhead, in Dumfriesshiro.

No. 24. — Model as i. ConsisH Mining District. This model, con.structed by Mr. T. B. Jordan, under the direction, of the late Sir H- T. De la Beche, shows the character of the nnd in a typical mining district in Cornwall, and exhibits the principal rocka, granite, and killas, intersected by mineral lodes, cross courses, &o. See description at p. 97.

No. 2!). — Model hi Comstock Lode asd rKO.)ECT£D Svtro TtKsEL,

Fvesenied by A. Sutro, Esg. The celebrated Comstock lode, shown in thia model, is probably the most productive silver-bearing veiu ia the world. It is situated n the eastern slope of the Washoe mountains, a ranpo of hilla unning parallel to the Sierra Nevada. The lode was discovered -a 1859, and has been ti-aced for several miles in a dicectido. nearly parallel to the magnetic meridiaii. "Sii.'£fteYCii\a

n THE.'EamCIPAL IXOOB.

bare been cstablishod on the lode, and several cities planted on ita outorofi, Vii'ginia city is at au altitnde of 6,205 feet. The Waahoe raage cu1iDiiia,tea in Mount Davidson at ou clevaUon of 7,827 feet. Thu mouatain in formed of syenite, ntiich, wilili 'ioiiB metamorphio rocka, constitues the nodena of the ranga A younger aeries of volcanic roclia, probably of Tertiary or Eoat- tertiary age, is represented by the eanidino -trachyte and 3aroa Uichtofen'a propylite ; the fatter conaists of a. &ie-grained paabt with emheilded ciyatals of oligoclase and homhlcndo. The aolo of tUo country and ita phyaioal featurea are well Bhown. m this model.

It was proposed a few yeara ago hy Mr. Adolph Sutro to drive a deep adit or horizontal tunnel, four milea long, through heart of the mountains nutil it oub the ivorkinga on the Gomstook vein, at a depth of about 2,000 feet. It would thus oSbrd an outlet to tbe waters which at preaent give considerable trouble to the miner j liut in addition to seonring draince it might be used for under- ground traiiait of the ore, and thua avoid the dif&uulty of traiiaport acroBH a hilly country. It was proposed to establish reduction works at the mouth of the tunnel. The model shows the direction of the projected adit, and indicatea by a thick black lino the portion of the tunnel which had been driven at the time the model was constructed. For atatiatica of production of the Oomstock Lode, see p. 9i.

Port Philip

The raising and cruahing of the quartz, and the extraction of the gold, are represented in. this mode!, which, however, requires no detailed explanation, since each portion ia furnished with a number referring to an esplanatflry key whiiih accompamea the model.

In the cose beneath are placed some samples of gold-bea/rmg gvtuix and " wash-dirl," from Australia, together with a model illuBtratinc the -ItwiraJtaw inode of timberim shafts. With theae will be foand a working model, hy Mr. J. B. Jordan, of a horinontal liigh-pneswn engine, fumiahed with a pair of fly wheels.

No. 27.— M

This model, which was constructed by Mr, T. Sopwith, repre- senta part of the mining district adjoining the river M"ent. It exhibits the thickueas and inclination of the strata of limestones, hazels (or sandstones), and orgillaaeous beds. In the front of the model ia shown the celebrated " Nent-force level." Thia work was projected in 1775, by Smaaton, and being judiciously carried out, it haa been of the greatest advantage to the district. "Nentsberry engine ahaft, represented on the model, ia aunk down to Mont-force Level, 3i miles from the entrance. The whole of thia distance, which was then navigable in boats, was surveyed by the author ia 1826 ; it has since been continued, as ahown m the model, on the top of the etratnm of limestone called the Scar limestone. The uaual mode of ontmnoe to the lead mines of Alston is by means of adits or water levels, made sufficiently largo for a horse to ti-avel in. The entrance or level mouth of Nentsberry Gren mine ia shown on the model, and the aeveral risoe by which access is gained to the vains of ore in the p-eat limeBtolie."—{t:iopi';ith.)

Centbal Cases. §7

'llio mineral vciitg are seen on the aide of this model deawnding in nearly a vertical direction through the varioiis etruta. It will be observed that those layera are not opposite eflch other on either side oF the vein. The cause jjrodncing the Jwtwa in which the mineral matter has been deposited has occttsiojied the snbsiden'JB of all the strata on one aide of the ?orf-e. Honoe the mineral vein maj haTe limestone on one side nnd sandstone on the other, or sand- stone and clay may lie opposite. It has been observed that the metalliferons character of the vein is in a great moasnre dependent npon the arrangement of the etratft on either side of the lode. lu thia district the lead is usnally fonnd in the Umestone, and when limeatonB forma both dieeks or sides of the vein it is generally there the moat prodnctive.

Old Carre crop-vein in the model has, to nso the 'minors' phrase, fkrown down tno strata 25 fathoms, whereas at WeUifill erof-reiti the amount of vertical disturbance is only 3 fathoms. The great Umeetone is 9i fathoms thick, consequently it follows that the last- named vein hae limestone eidee for 64 fathoms (39 feet).

No. 28.— Model o? Landslip at Akmouth.

At Christmas 1839, thia great landslip took place. The model is conBtmcted on the scale of 120 feet to an inch, and it represents a mile and a quarter of the country over which the subsidence took place. The length of the great caused by this snbsidence was 1,000 yards, the breadth 300 yards, and the depth varied from 130 feet to 210 feet. Twenty-two acres were sunk in the ehasm. The Eev. W. D. Conybearo thus describes the phenomenon ; —

"On the moraing of Tuesday the 24th, about three o'clock a.m.. the family of Mr. Chappie, who occupied the farm of Dowlauds, abont half a mile from the commencemont of the disturbances which ensued, was alarmed by a violent craHhing noise ; but nothing farther was observed through that day. On the following night, however, about the aame hour, some labourers of Mr. Chappie, the tenants of cottages bnilt Mnong the mine of the aoining under- cliff, hiu'ried to the farm with the information that flBsnrefl were opening in the gronnd around, and the walls of their tcnomenta rending and sinlcing. Through the course of the day following (Ohristmas) a OTeat subsidence took place through the fields ranging above BendonlJndercliff, forming a deep chasm, or rather ravine, extending nearly three-quarters of a mile in length, with a depth of from 100 to 150 feet, and a breadth eioeeding 80 yards. Between thia and the former face of the undercliff extends a long atrip ex- hibiting fragments of turnip fields, and separated from the tract to which they once belonged by the deep intiervening gulf, of which the bottom is constitnted by fragments of the original Burfaee, ijirown together in the wildest confbaion of inclined terraces and columnar masses, intorsected by deep fissures, so as to render the gronnd nearly impassable. The insulated strip of fields also which haa been mentioned is greatly rent and shattered. The whole of the tract which has been aubjeoted to these violent disturbances must be estimated on the most moderate computation as exceeding three quarters of a mUe in length by 400 feet."

No. 29. — Model op Peat Moss eh Auchiisbray EsriiE,

Lajjaukshibb, by Thomas Giib.

This model of a peat moss, which slipped on the 12th and 15th

Augast 1861, is acoompanied by a descriptive label, aSoYissisQSi.-

cient ejqjtanadon, which it is nnneceBSMry toiepeatWtc.

68 The Tetncipal Fioob.

No. 30.— MoBEL OF HoLMBDHit MiNE, l]f Mr. T. H. Jordan.

In this model of Holrabnsli mine, near Callington, in East Corn- WflH, the excavationH are repreaented by solid modelling, whilst the BtUTonnding country bolow the adit-level is supposed to bo removed, and hence appeara aa apace. By this novel principle of modelling, for which a prize medal waa awarded at the International Exhibition, 1862, the direction of the lodee and the details of the undergroond workinga are distinctly seen, whilst the difference in the mineral con- tentaof the reins is repreaontd by a system of colotu-ing, explained by a label attached to the model.

In 1863 Holmbnsh mino pi'oduced 1,048 tona of copper ore and 416 tona of lead ore. The workinga are, however, now abandoned. A fine aample of the copper pyrites ie placed beneath the model.

There are alao exhibited in the lower part of this case a remarkablr large cryatal of Gatiadian Mica, belonging to the variety callw phlogopite ; and a fine example of magriBtic iron ore from Sweden.

A email model showing the Geology of Jeruaai&ii ia placed here temporarily.

No. 31.— Model op STmrACE-woKKiNGs of a Newcastle Coal-mt. Presented hj Mr. John Wales. This model, the several parte of which are lettered, representa the arrangomenta used at a North of England colliery, for raising, acreeninK, and loading the coals. From the face of the workings la the pit, the coal is broneht in tubs or waggona (G) which are placed on cagea (D), and raised to the surface by the winding engine (A), which, with its two boilers (B), occupiea a prominent position in the r part of the model. Arrived at the top of the pit (C), the tuba e placed in the teaming a'adlee (F), and the coals discharged npon the screens (I, I), tha large coal paasiug du'eotly into the ohaldroa waggona (H), while the amaO coaJ passes into the box (K), whence it is transferred to the small-coal screen (L) by which ib ia sorted into the three sizes, nut, seconds, and duff, discharged throngh the shoota marked respectively M, N, 0.

In the same case is a model of coi/es timd at Cowden ColUe/r, Dalkeith, presented by His Grace the Doke of Buccleuch and QneraiB" berry, K.&. There is also exhibited in this case a model of a hori- zontal winding engine, with spiral drum, for colliery work.

Models op the Machikery fob Loadino Coal.- In lower oompwi*

ment of CsaeNo. 31.— Presented hjMeesre. Vivian atid 8<ms, Ww>

IcKk, Olamorganghire.

It will he observed that in one instance the waggon on the rails

runs on to a atage, which is lowered into the vcHael'B hold, when

it is opened at the bottom, and the large coal quietly deposited in its

Elace, the stage being returned to its original poeition by counter- alanoe weights. The second model is similar in general principle, but here a box slang at the end of a crane ia employed instead of the sliding stage.

No, 32, — Specular Ibok Oas from the Island op Ascensio)*. A notice of the volcanic island of Ascension will be found in the " Catalogue of Eock Specimens," Srded., p. 220. Tlie formation of apecnlar iron ore in volcauoB probably roanlta from the action of watery vaponr on perchloride of iron ; hydrochloric acid being set free, whilst peroxide of iron is deposited in a, crystalline form.

SfC."

Cesteal Cases. 69

Hefereiioe to 'Wall-case 19 will show th&t specul&r iron ore ia bj no meaDB an unfreqaent volcanic product.

No. 33. — Case op Minkral Specimens. Several remarkably fine mineral Hpecimena, too larye to be ex- hibited elHCwhore, are here grouped together. Deaoriptiona of these will be found nnder their respective headings.

No. 34. — GsoLOGiCAL Model of Most Blanc.

delwa

, its altitude being 15,732 feet above the Hear-level. The vaa constructed by Mr. J. B. Jordan. It is to be noticed that the vertical and horizontal scales are the same, ao that the heights are not exaggerated, aa is generally the case in geological models and BectionB.

The anowline, or limit of perpetual snow, comes down to abont 7,000 feet below the anmmit of Mont Blanc, and the model showB with great clearnesB the system of glaciers with their different forma of moraine, — lateral, medial, and terminal. The deep red colour on the highest part of Mont Blanc and the aurrounding hoighta repre- sents file peculiar rock called protogine, a talcose variety of granite, whilst the paler red denotes mica schiat, and the bright yellow, on the opposite aides of the valley's of the Arro and the Dora, marks tio diatribotion of rocks of liasBic age.

No. 35.— Model o? tee Pass of Mont Cbnis.

This model ahowa by the eontoor-lines the varions elevations, and ejhibita the physical features of the country. The district repre- sented doea not extend BnfGciently westward to include the country penetrated by the celebrated railway tonnel.

In the upper part of Wall-tasea 8 and 9 are several other illuatra- tions of this ayatem of modelling.

The lower compartment of the case contains a fine sample of qohl and silver ore fnm, OliiU. Thia specimen ia from the Maifre de Dios mine, near Coqaimbo. It contama the precious metals in the pro- portion of 12 oza. of gold and 220 ozs. of silver to the ton.

A few other mineral apecimena also find place here, including a rich maas of silver and copper ore from Newfoundland, presented by the Hon. C. F. Bennett.

No, 36. — ArsTHAiiAN Gold, &,c. It appears that in 1839 Count Strselecki discovered traces of gold in Australia, but on relating the circnmetance to the Governor of Hew South "Wales secresy was eojoined, and the Count never" reverted to the subject. In ISil the fiev. W. B. Clarke wrote to a friend in the colony, mentioning that he had found gold ore, but neither of those facte was publifSied in the colony, and they were wholly unknown in Europe. The atndy of the auriferona tracts of the TJralian monntnins enabled the late Sir E. I. Mnrchison, in 1844, to predict the discovery of gold in Anstralia. " Having," writes Sir E, Mnrchison, " in the yeai' 1844 recently returned ftom the anri- ferouB Ural mountains, I had the advantage of ejtamining the nnmerouB apecimeus collected by my friend Count atT7.a\wJBi.iiaB.

TO THE PRTllrCTPStf.' FTOOB.

the etistern chain of AnBtralia. Seeing tho great Himiiarity of the rocks of those two distant cotmtries, I coald have little diffionlty in drawine a parallel between them ; in doing which I waa naturally struck uj the ciroametaDce that no gold ' had yet been fonnd ' in the Aaatralian ridge, which I termed, in anticipation, the ' Cordillera,' Impreaacd with the conviction that gold would, sooner or later, found in the great Britiah colony, I learned in 1846, with aatiko: ti on, that a specimen of the ore had been discovered. I therentwn encouraged the nrjemployed miners of Cornwall to emigrate and dig for gold, aa they dog for tin in (he grarel of their own diatriot. Tlieeo notes were, aa far ae I know, the first iiabliahed relating to Australian gold."

Of the Avrrifarout DtI/1 of Victoria wo have the following accoimti by Mr. Alfred B. 0. Selwyn, late Geological Snryeyor of that district, formerly of tho Survey of the British Islea : —

" Thia formatitm, of very late tertiary date, Taries in thidcnem from a few inches to 100 feet and upwanlH. It couaiats of stratified and asstratified mosaea of ferrnginoaa clay, aanda, and gravel, inter- spersed with angular and partially rounded fragments of clay, HlAte, Gandtono, quartz, &c.

" It occnre almost univeraally, distributed in the gullies, on the flats, and oyer the hills, ocotipied by the palaiozoic strata, and Is, in fact, formed from the decomposition, breaking up, and spreacUng out of tho immediately subjacent recks ; the fragmeuta found in it bem, with a few local escoptiona, soldom mach water-worn, and bearing no evidGuco of having been transported from a diatanccb The lowest stratum or bottom almost always varies in colour and character with the nature of tho subjacent rock, whether a ferru- ginous clayey sandatone, forming a red or mottled ieiTHginous sandy olay or gravel, or a soft felapathic slate, producing a white pipe- clay, &a.

- " With respect to the origin ajid present position of the gold, there can, I think, be little doubt, lat, thattfaowholeof ithasbeenformed in or near the quarts veins which are now aeen traversing the palteoBoic strata ; 2nd, that itapresentpositionin thedrift is entirely due to the decorapoeition, breaking up, and spreading abroMl.of these quartz vena along with the ordinary sandstones, slates, Ac of the diatrict."

&EMa from Aiietralia. — Specimens of sapphire, topaz, zircon. Bad. other gems occurringinthe alluvial gold-deposits are here exhibited. With these are two Australian diamonds, one of thoiu being Iha eai'lieat brouglit to this country. Several quartz cryatala have heeB brought to England under the impression of tbeii' being diamonds. A quartz ciyatal is usually a six-sided prism, with a six-aided i pyramid at its etid, a form which the diamond never aaaumea. Diamonds are either eight-aided ci-yetals (octahedrouB), cuiies or dodecahedrons ; or more complicated forms closely related to these solids.

Ko. 37.— MoDEL OF THE Alps ajto the PiiMws of Lombardy. Thia model, presented by the late Dr. Fitton, ia based npon Jomini'a map illustrating Napoleon's wars. The mountains re pre-' sented include tho Alps, from the sea neai-Jy to the end of the Bhostian chain, the whole range of the Jura, and a part of the Apennines. It eibibits the physical features of the country, but not ite geology.

. Central Cases. 71

No. 38.— Eiecteo-Metallcegt. Head of Ocean (Xo. 39). Head oi' Melpomene. (No, 9)preeented hjEVdngtan, Ifasoii, and Oo. — near the gallery atflire on either Bide. BpecimeBS in Wall-caset; 16i 16, 17. Fraine on wall near Oaaa 14-.

The discovery of the process of the electrotype, or cloctromotal- lur, wag first annoiinced to the public on the 4th of May 1839, l>y Profeaaor Jacobi, of St. Petersburg.

On the 8th of May Mr. Spencei- announced to the LiTcrpool Polytechnic Institution hia diaooverv ; and on the 22nd of the same month Mr. 0. J. Jordan published in the Moohanics' Maganine a description of his method. Here we have an instance, not an un- common one, of three men, Jacobi, Spencer, and Jordan, working at the same time upon a most important discoyeiy, without eitter of them being in the least awoje of the reacarchos of the other.

Electro-metallurgy depends upon the law eetablished by Dr. Fara* fiay, that the electricity developed by the change of state, oxidation, of an ef[uiTftlont of one metal, aiue, would effect the decomposition of an equivalent proportion of another metal, copper, fi'ODi its solution.

The form of a voltaic battery for the electrotype process is exhibited. A plate of ainc and a plate of copper being placed in some diluted Httlphuric acid, an action is immediately establiehed on the zinc; it is first osidieed, and the osida of zinc formed ia converted into sulphate of zinc, bj[ being dissolved in the sulphuric acid. Dnringtho bsidation of the zinc, electrioity is developed, which passes to the surface of tlie copper plate. If from each of those plates o copper wire ia carried into a solution of solptiate of oopper, a piece of -p\skn copper being attached to one wire and connected with the copper plate, and Oil engraved plate or a medal to the wu-e couueoted with tho zine plate, the resnlt will be that copper will be deposited in a metallic ibrm upon the engraved plate or metal , and copper will bo dissolved off from the plate on the other wire. In the frame on tho wall, near Caae 14, is a plate of copper aa precipitated, another plate as thrown down upon an engraved surface, which gives all tie lines in relief; upon thia another deposition being made, the result is, as shown, an esaot fao-simile of the original plate. As au. example of an applica- tion of- tbia, the maps used by the Geological Survey of Great Britain arc copied from the plates of the Ordnance Survey by the aleotrotype process upon the plates thus obtained are engraved the geological lines, signs, and remarks, so that every information rsqnud by tho public appears on the geological map, withont at all disturbing the character of the ordnance map. Many surfaces, sach as clay, plaeter of Paris, was, itc, aro not conductors of electricity, and consequently upon these metal cannot be precipitated. The late Mr. Bobert Murray diaoovered that black lead, lunibago, rubbed over such articles gave them at once a. conducting surface, and rendered them fit for receiving, by the voltaic battery, a metalHo precipitate. Thus are formed several of the objects exhibited.

If silver or gold is to be deposited, the osidea of these metals must be dissolved in cyanide of potessinm or some such salt. The article being immersed in this, when connected with the battery, silver or gold is deposited. This is electro-plating. To prevent the silver from presentmg a granular or dead appearance, a few drops of the bisulphide of carbon are added to tho solution.

The SotaniccU Sjpedmeiis, Sfc, of which there are exhibited electro- type coatings, may be prepared by dipping, fii'st the grass or leaves into a iolutiOD of phoBpfioms in bisnlphide of carbon, then Ivai-asf, the artide into a solution of nitrate of'sA-jei;. \.V\o. vo. -A

72 Thb Miincipai, Floor.

pbosplioras left upon the surface occasious b. precipitatioa of a finely-divided coat of silver, upon which, when connected with the hotteiy und placed in the proper Bolntions, anj quantity of either copper, ailver, or gold cen be deposited. It is impossible to do more than thus indicate a few of the proceasea hy which electro -metallurgy has l>een cai-ried forward.

Some of the most iutereating results have lieen the coating of iron with copper, and the elecCrO'Chemioal deposition of the componnd metal, hrass, of which some examploa are shoivn. One of the moat recent upplicationB of electro-metallorgj on a large scale has been the electro-deposition of nickel on various metals. It ia believed that the nitrkel ia beat thrown down from a aolntiou of a double salt. Booh ae IV doable sulphate of nickel and ammonia. The process ia now largely worked iu London and Birmingham, and several Epecimenl, presented by the Nickel Rating Co., Limited, are exhibited in the opposite side of the glass case. Those samples show the deposition of nickel on slabs of copper, tin, cast-iron, ateel, brass, and GermBa

PI!OSPHOR-BBOB. — The shelves of this case, on the opposite side to that containing the electro-metal lurgicai series, are devoted to the eshibition of spccimena of this alloy, presented by the Phosphor-' bronze Co., Limited. A good deal of attention has recently been directed to the value of adding phosphorus to bronze, wliei-eby the quality of the metal is said to be greatly improved. EsperimentB have shown that thin alloy poasessea high tensile strength, and other valuable mechanical properties ; and its mannfocture haa consequentily been established in this country. The manifold appUcations' of phosphor-bronze are well illustrated by the specimens exhibited in the case before us,

No. 40. — BozoQn in Lahiientus SiarEirmjQns Lisiestonb.— Presaiiiod hi the tale Bir W. E. Logan, Director of the Geological Surveij of Canada.

The Laorentian rocks of Canada, which are developed on a vast scale in the country north of the St. Lawrence, consist chiefly of cnormons deposits of gneiss, containing in certain parts intercalated beds of crystalliTie limestone. The system is clearly separable into an upper and a lower series, and from the uppermost limeatoBO- ' bandm the lower group the block before us was obtained. CCmai- derable interest natnrallj attaches to the late Sir William Logan's discovery of organic remains in these metamorphio rooks, whi<m ftM the oldest stratified deposits at present known. The fossil, which has received the name of Eoioan. Canadense, is referred by Dr. Carpenbor and other microscopists, to the group of foraminifera.. These are nnimala of extremely simple organisation, each foraminifor oonaiafr- ing essentially of a gelatinous mass of protoplaani or " sarcode," nsnally enclosed in a calcareous covering oi- tost. In the eoaoon this calcareous shell is but little altered, whilst the easily decomposible Barcode is replaced by mineral ailiontea, such aa th green serpentine in the block before na. When a thin section of this ibasil is treated with hydrochloric acid the calcareous shell is diaaolved while the mineral silicate remains in the form of casta of the original body- chambers of the organism. Such a decalcified aection ia exhibited in the opposite cflae. No. 4S.

No. 41.— Model or tub Chain of Pi'vs, AuvEttGKE.-PrcBenwi hi tU

late G. Poukti Scrope, M.P., FJt.S., c.

Little more than a century ago two French travcllora reluming

from Italy observed that the rocks in certain parts of their route

(Ntbal Cases. 73

through. Central Fmnce bore a etrikiiig reBemblaiice to the vol canic products of VesuviuB. Although at fiwt racciyed with considerable oppoBitioD, the truth at length became establiehed, that at a compa- j-atively recent geological period the interior of Fimice hud been the theatre of energetic and frequently-repeated volcanic action. One of the most intereating groups of theae estijjct volcauoa is repre- sented in the model before ua.

The volcanic hills of the departmont of the Puy-de-D3tne form an iiregnlar chain, running ucarlj north and EOutb, and rising from the great platcaa of granite irhich forms eo prominent a feature in the geology of Auvergne. The surface of thia granite presonte aevei-al depressiona, formorlj occupied hy lakes, the existence of which is now marked by certain fresh-water deposita, of which the largest forms the fertile plain of the Limagne, represented on the eaatcra side of the modeL Passing westward from the alluvial valley of the Allier, we cross the calcaroona maris and other lacustrine deposits on the margin of the Limagne, and reach the eaebera escarpment of the granitic table-land which, extending in width for about 12 miles, slopes on the westDrn side to the valley of the Sioule. The chain of " pnys," which rises from this platform, includes about 70 rolcanio hilk, of which the largest ie the Puy-de-Dflme, a moun- tain rising 4.844 feet ubm'c the sea level. Most of these hills are composed essentially of the scorite, lava, and other volcanic products, which, accumulating around the orifices of eruption, have termed conical hills, often presenting at the snmmits well-defined craters, fi'om which, in many cases, distinct streams of lava may be traced. The Piiy-de-Dfime and a few other hills consist, however, of a peculiar tracbytie rock called domita. A descriptive label, by Mr. Scrope, accompanies the model, and a notice will also be found in the Oatalogne of Models. For further information a(?e " The Geology and Extinct Volcanos of Central Franco," by G, Ponlett Scrope, M.P., P.K.S.. ic.

In the drawers beneath the model is an interesting group of rock specimens illiiBtrating the geology of the district, presented mostly by Dr. 0. Le Neve Poster, B.A., P.G.B.

So. 42. — Cbtsialluib Fl-bitace PaoiracTs.

A small table-case at the head of the steps leading from the Kail, opposite to the large model of Auvergne, contains a series of cryslal- line furuace products, forming a companion group to the specimens of slags on the opposite side of the steps (see p .Hb).

Among the more notable specimens attention may be directed to some tine examples of the bright copper-red cubic crystals of a peculiar compound of titanium (p. 84), not onfreqnently found in the bear "of blast fnruBces. These crystals t*) which Dr.Wollaaton first drew attention, were formerly thought to be pare titanium, but it has been shown by Dr. Wohler's researchca that they consist of nitride of titanium with cyanide of titanium. The specimens of ciystftllized oeuJe of sine from the iron furnaces of Westbury are also interesting. Tho fine specimen of a furnace product having the composition of magnetic oxide of iron, and eshibitiu ou aggregate of octahedral crystals, will not fail to catch the visitor's eye ; nor will the other artificial niinorala escape attention, such as the crystals of galena from the Freiberg lead fiimaoea, or of oiihoclaae from the Hortz copper-works. There is also exhibited here a boautifull- orystalline compound of peroxide of iron and limo, thus related in composition to the nataral group of spinels, which has been produced by Dr. Percy, who described it in the rhilciihieal Mugaeiiie for June 1873.

THE.FItmcieiX. TUX)R.

No. 43. — Ap t Appucinoss of the Metals.

The oljject of the iHl,iclea grouped in thia caae is to ahow oharactera of the metals in a pnro and a mixed state, and to iilnBtnite their application to works of art and to art manufacture.

Slafitetfee in tin and copper show tho characterB of the Tnetals in their ordinary states. Ouo iu hroM exhibita the result of combimng copper and sine, while those of Baphael and Michael Angelo ua bronzes, in the proportion of 90 parta of copper and 10 of tin. lla statuette of Humboldt is of zinc, but it has been Bubsequently coated by tho eleotro-chcmicai proeess.

The silver and hronxe vases are copied from antique specimena found in Pompeii, and in the Musoo Bnrbonico at Kaples. Corintliian (wone, in which one of them is oast, consists of two-thirdg copper and one-third silver. This composition ia said to receive its name from its having heen discovered by the occidental melting together of statuea of cfper and ailver which were destroyed by firo at Corinth. At least TOO 3'eBr9 before Christ the art of casting bronze stotuea was carried to a high degree of refinement. Pliny informa ua that it was during the reign of Alesander that the piro- daction of brtmza atatues received its greatest extension nnder the guidance of the artist Lysippu, who improvedthemodeaof moolding and caeting. Pliny calla theae etatnea tne mo6 of Alexander. Athen* is aaid to have contained above 3,000 bronze atatues. Bhodes, independently of its lighthouse and its bronze tower, was decorated with as largo a nnmber, and in Olympia and at Delphi tbey appear to have been no less nnmerons. We are thus enabled to form some idea of the extent to which metallnrgy was cairied by the ancients. Eleetrum waa one of tho celebrated mixed metals of the anoienta, of which we have here an example.

Our standard ailvei- {see Silver Taae) has a composition of 222 silver and 18 copper; by the admixture of the latter metal th.e required hardness is obtained without interfering with the colour of the ailver.

An example of a miaturc of piatinnm and silver will also be found

Tho Gfaiiati silver' fdyi be noticed in connexion with the nickel series {p. 114) ; and the alwninvum broma will lie mentioned in the description of an adjacent Ciwe (p. 75).

ITie Bronze lAnards and other Uattinss.'—CaaihigB of this kind are obtained by pouring upon the living animala a cream of plaster of Paris ; thia soon aeta and the animal dies. By expoaing the piaster after it is dry to a high temperatore all the organic matter ia destroyed, and a perfect monJd' is left, into whii liio metal is

Eared, Chantry waa one of the first to employ a process of thia id, for the purpose of obtaining fae-sitniles in metal of leaves and flowers.

No. 44.0hinesb Bronzes, itc.

Productions of thia kind have long been made hy the Chinese, and they exhibit very great ingenuity in theii- modes of moulding, and adjusting the niould so as to secure, as nearly aa possible, a perfect coating by one opai-atiou, without tho subsequent nae of the

In many instances the model i

all the ornamentation, inscriptiont .

tliia is then covered with the clay which ia to form the monld, and when dry the wax is melted out ; the metal which aafasequeutl in. ft.

. Central Cases. ' 75

fltiid stato eappties it place fills every part, and thoa is obtauiad a casing of great sharpneBS and coiTOCtneBH.

The tamr-iamg and ci/wbalg ojbrotvie of the Chinese are furged with the hammer, as indeed ore man; of their hrcmze artictea. The com- position of theao appears to be 78 of oopper and 22 of tin. This alloy, when, newly cast, is very brittle, bnt being confined betAVoea diacs of iron heated to cbeny rednosa and pinnged into cold water, it becomes maUeablo. The Chineee belltctoimff — which we render goiiri, IB nanally composed of 80 copper, 20 tin ; thetie ore worked with the hammer aa deacribed. The Cbioese fretinently employ copper alone, and give it artifically the character of bronse by spreodiog Tipon the surface a. paeto of rerdigria, cinnabar, aaj anunoiLiaa, ajid aJnm, and then exposing the vessel for some time to the action of a moderate firo.

0}iM\fsa MvrroTt. — Many of these mirrorB poBsesB the very remark- able property of reflecting from their polished earfacc the Hgnre which is wroQghb apon the back.

Chinese <?opper. some of that metal and several alloys from Zan, a Oliinese Iocs and key, &c., will also be found in this case. Tuera are likewise some examples of Indian niello work on tinned copper.

So. 45. — MZNEHAI, SrECJlIESS.

Two fine mineral spocimcna are placed under glaea shadca on small table, between the Fedestal-caeea Noh. 44 and 40*. One of the apecimena is an example of fibrous muhiickile, or green carbonate of eopper from the Peaks Down Copper Minea, New South Walea ; ths other is aa attractive specimen snowing crystals of AiiuKcm atoti or green fnpar, witb cgaartz and spathic iron ore, seated on the waQa of a carity in a graaite rock from Bockport, MaaflochnBottB, 0.8.

No. 46. — METEORiraa, ALfitmnrit, Pbecious Metals, &c.

for I

metallnrgical series, but a few other specimflns, each aa tba

meteorites, are also included in thia collection.

Meteobiees. — The small collection of meteorites hero exhibited, inclndes some fine specimenB of meteoric iron and eeveral fragments of meteoric stones. The former consists of iron alloyed with a small quantity of nickel and cobalt, and freqnitly contama graphite and other minerals ; whilst the latter are agegates of variona simple minerals, sneh as felspar, augite, and olivine. Some of the apeoi- mens of meteorio iron show tae figures of Widxoannetadten, i.e., the crystalline structure developed by the action of nitiic acid on a poliflhed surface. Humerona meteorites have fallen in varions placea, but the origin of theee masses is still wrapt in obaonrity ; the moat rational theory is that of Ohladni, which may bo expressed in the following general terms; — Through the interplanetaiy apaoes, and it may bo throngh the interstellar spaces also, vast numbtffB of small masses of solid matter maybe moving in irregnlar orbits; and these, as they approach any planet of powerful gravitation, anch as the earth, will be disturbed, and may fall towards its sorface.

The theory of Laplace was, that these aSrolitea were projected fi'om Tolcanos in the moon. It hns, however, been proved that there aro no active volcanoa in onr satellite ; consequently this theory eannoti be reoeived.

AminsluM. — In a stato of jKiwder aluminium has been known since the daya of Davy ; Oersted wrote on it bumI some of its alloys ; andWbhler and other chomistfl prepared it. it.Sit.CiMcatss'iiisi

t6 THEJOOIffCIHU. nAOL

wan, however, the ftrat to obtain tha metal in a periootly coherenl t'urm, Until recently tho miuoral called cryolite, a doable flaoride ol atamininm and sodinm, of which a epecimen ie shown, was th principal Hoarce of aluminmm ; bnt at present the metal ia exclnaivelj obtained from laiixite, a Fi'ench mineral, containing more than one- half its weight of aluinina, together with peroxide of irou, silica, titaninm, and water. Sy heating a mixtore of bauxite and aoda-tub an alnminate of soda is obtained, and fi'om a solntion of this aalt, alumina in the state of hydrate may ho precipitated by an ooid. A mixture of tbia precipitat-ed alnmina witli common salt aod charcoal is treated with chloripe. and from the double chloride of aluminiam and sodium thus formed, metallic alomininm is obtaiuBd by the reducing action of sodiam. Each stage of the pTOOeas is btse illustrated, Alaminium has a epecific gravity of 2'56; that of silver being 10'5. It does not tamish under circumstances in whicli silver, tin, and zinc blaken; and alloyed with copper it forma the wellknown urummtHnt troiwe, of which several specimens are hero shown,

Pbecious Mbtals. — The moat interesting among these are specimens of platinum and ita adsooiated metala.

Platinum was unknown in Eoropo till about the middle of the last century, when it began to be imported in small quantitiea from Soatb America, but tVom its infoaibility it was nselesa.

Dr. WoUaaton discovered a method of fusing platinum, and thus of rendering it available in the arts. Platinum iirat engaged the attention of the Buasians in 1824, when rather more than one pood wag collected. In I83S more than 13S poods were obtained, and within a few years the Bussians issued platinum coins of the value of 3, 6, and 20 silver ronhlea. (See p. 96.)

Silver coined at AlerystwUli. — The CardigauHbire lead mines i

eapeaially remarkable for the attention which they excited daring tho latter half of the 16th and the begiiming of the 17th century. Sir Hugh Uiddleton realined a. large fortune from those mines, and expended it in bringing the New Biver from Ware to London, After Sir Hugh Middleton's death, Mr. Busboll, the secretary of Sir Prancia Bacon, bought the mines of Lady Middleton. These mines were extremely profitable to him, aJid availing himself of an inden- ture of Charles I., dated 30th July 1837, he estahliahed a mint at Aberystwith, Mr. Waller, in his account of tho mines of Cardigan- shire, Bays, "He kept a mint at work at the silver mills of Cardiganshire fi-om the bullion he had at this mine, and is said to have clothed King Charles the First's whole army from part of hia profit in this work." It is certain that during the civil wars, Mr. Bushell sacrificed bis fortune in the King's defence, and that he placed himself at the head of a regiment of miners which he had raised in support of the royal canse. Aberystwith Caatlo was besieged and taken by the parliamentary forces, and the mint and mines were abandoned. Tho coins exhibited are some of those coined by this Mr. Buahell.

Antjmosy. — Thia metal is always extracted from the ter-sulphide (pp. 85. 92), which is separated from ita associated earthy impurities by simple fusion, and in this state is known as crude anilmom. By careful roasting, the snlphide ia converted into an oxide, which is then reduced to the metallic state by fusion with carbonaceous mattera. Antimony ia largely nsed in the jireparation of type metal, which consists of six parta of lead and two of antimony ; the common stereotype metal bemg bat one part of antimony with aix of lead; and in other proportions it forma the alloy on which music is

OENTEAI CiSES. TT

engraTsd, Many (untiniQiiial ci

as tartar emetic, James'a p(

medicinal preparations having diBorderod the inhabitanta of s

monorStery, the metal is eaid to have derived its name {oaiti-mtniii)

antimony,

Antiimonjj Cup. — When wine was allowed to stand in these cups, tartarized antimony (emBtie la/) was formed and dissolfed, and coneeqnently when the wine was drank it produced BicknoBs,

Gili Copper Cup obtained from the copper mine of Hermgrond, inHnngary. In " An Aei:i3ii7it ffivea bv Dr. Edward Brown coiicsetiiag the Copper Mine al -groimd in JIvmga/ry," the following deacrip-

" There are also two springs of a vitriolcb water, which are affirmed to tarn iron into copper. They are called the old and the new %iment. These springs lie deep in the m.ine. The iron is or- dinarily left in the water H days. I here present yoa with some pieces of it, and with a heart and chain, formerly iron, but now appearing to bo copper, Divera of these pieces I took out of the old !ciment. They are Hard within the water, and do not totally lose their fieore, and fall into powder, as you will perceive hy them ; thej" will easily melt. I have sent a piece melted wilhont the ad- dition of any other sahatance. They make handsome cups and vessels out of this salt of copper. I drank out of one of them wheu I was at the Verwalter of Merra-ground, his house. It was gilded over, and had a rich piece of silver ore fa-itened in the middle of it, and this inscription engraved on theontaider — " ' Eisen war Ich, Kupfcr hin Ich ; ' SUber trag Ich, Goto, hedeakl mich. ' Copper 1 am, but Iron was of old ; ' Silver I carry, oover'd am with gold.' "

PLil. TrauB. Vol. 5. 1670.

If iron ia placed in a aolntion of sulphate of copper, the iron ia dissolved as salphate of iron, and copper takes its place. This proceas is termed eementaiivm, and the cups exhibited are thus produced. The inacription on the cup ia Oatt zeigt an Mir eeiri grose MacJU der ansa Eisen - Macht, "God shows in me hia great power, who oat of iron makes copper." The date of this cup is about 1650.

BiSMCTH. — The ready fuaibility of this metal renders its metallur- gical treatment exceedingly simple, themetal being readily separated from any foreign matters by fusion. Some sinKularly beautiful examples of bismuth, crystallized artificially, are introduced. The iridescence is given to the aurface by the regulated action of heat. Bismuth is naed in the formation of type iiietal; p'?ii-ter, mJder, and /risible metal. An alloy of bismuth 8, lead 5, and tin 3, will melt at a temperature lesa than that of boiling water.

OAmnrm, — This somewhat rare metal is esfiracted from the zine smelted from eadmiferous blende. Specimens of metallic cadmium are shown in the form of ingot and aheet. The sulphide, known as Cadmimn yeUow, is employed by artiata ; but the metal has not yet found any important application, in the arts.

Tin Plaie.— This ia sheet iron coated with a thin layer of tin. The iron, which must be manufactured with much care, coke being naed, is roOed into sheets of the required thinneaa. The sheets are cut into rectangular pieces, and these are freed from every pai-tic!e . of adhering oxide, or any impurities which would inevitably prevent the adhesion of the tin. The plates are bent, into aaiJitt qt ,

78 THE.FWKOmUrmOOB.

nmed "i reTWberatory dvpii nnii heated ia redness. Theyara withdraiVTi, plunged into iin neicl liath, and oncQ more exposed M ignition in the famace, by which they are aaid to be scaled. 35ib dates are paased throngb iron eylindricttl rollers, and then inunersed for ten or twelve houra in an acidaloua Ije, made hy fermenting bran water, after which they are exposed to the action of dilute anlphiirio acid, nntil they beoome perihctly bright. Being cleaned off 'witH bran, the platca are piuned into some melted tin, which ia oovared tm the surface with about four inehes of tallow. The plate labse- qnentlyia dipped into wiothorpotof metal, called "Wash-pot So. 2," and then cleaned off by the workman. A sidlfnl tin-plater can pass 5,625 platoa through bis bands in 13 hours.

MiBtellamea. — The mlHoellaneons Bpecimens in this case are nnmoronB to be described individually. They include som.e of tho rarer metals, such as eiamplea of iSaHiiira anid i?iiJMii— twometsJa discovered by aid of spectroni analysis, tho former in 1861 by SCr* W. Grooke*; the latter in 1863 by ProfeHSore Reich and Biohter of Freibergin Siiitony. Examples of several useful alioya are exhibited, ench as Briinnma iiieial and specahtiit metal. There are also a few ' specimens illostrating the opplioation of metalha abio, but theas will be described elsewhere (p. 118).

This eoncludea our survey of tho serieB of eases and m.odela in oentral area of tho Museum. Of the remaining cases, INos. 47 to are described in the matallnrgical section (p. XIO), and Nob. 58 to in the ceramic and vitreous section (p. HO). Before passing to these, however, it is desirable to call attention to a few miscellaiieoiia Bpecimens distributed through the room according to convonienee of

SunDBT Specimens.

Commencing on the eastern aide wo find near the Head of I£elpo- raene, No. 9, several Qwei-iw or ancient handmillB used for grinding com. Most of these being formed of a siliceous couglomentte or " pudding-stone," a rongh surface ia constantly maintained by the unequal wear of the flint pebbles and the cementing substance.

A Jtyio/nesB Vasa in doisanMc encemel stands on a pedestal between "Wall-cases Nos. 63 and 53. The vaae ia broken at the sbonlder, biitl this fracture serves to show the method of manufacture, which is described at p. 165, Beneath the vases are some blooka of hmmatUe (p. 108), and a large specimen of oyomo-Tiiirida of tUanimn (p. 84). Satweoa Cases 46 and 47 will be found a large block of ipalJUa iroji ora from the Bi'endon Hills (p. 109), and an iron-casting (p. 56). ISeax Caae42 is a fine FlBm/khMonvmentolBraea. This brass forms pajof the mised-iQotal earieB exhibited. It is of Lodewyc Oortewille, of Cortewille, near Liege, who died in 1504, and of his wife Cole Tan Castro, who died 1496. Tho analysis made in this eHtablishmenb shows its composition to ho — Copper, 64'0; Zinc, 29'5i LmwJ, 8"S; Tm, 3-0.

.On the model of the Sheffield Steelworks, at tho northern end of the room, will be found tho aiici&it "bronze dWh for measwing had, described at p. 107. Near Case 14 the wall-epace is occupied by an eheifoiype (p. 71), and a fine irmi-aaglmg of Leonardo da Tinoi's " Last Supper" (p. 56). Some beantifol eleetrotypft east in eliutio moidda are hung between the ombaymenta on this side of the roo An amtsieiA coat of mail, showing the method of riveting the links, will fie found here; and an ancient Irrante Greek trimd stands near. Some mosnits (p, 165) nro placed on the staircasea leading t

"HRrPISH 0BG3. .79

the gallerieB, and here will also be found m) teitief-wtour ' illnstrBrting geologioal econerj. Several iiuvpi mlanted to UiuaWaie Ihe progrees of the Geological Burvay are suspended boieatb, tha first llBry, and con be di'awii down when nsceaaibty for reference. Tliere 18 also a copy of WilUaim SmUh't first large geological map of England ami Wales, published in 1819. By comparing this with Qreenoitgh's 5iwp published by the Geological Society in 1865, a copy of which hftngB on the opposite side of the room, it will be aeen that the broad features of the geological sti'ncturo of Eugland were laid down, with remarkable accuracy, by the " FalEer of Bngliah Geology,"

THE MnraEAL COLLECTION.

The Mineral Collection of this Museum, ie arranged in the series of 56 wall-caseB around the principal floor, and in the large horse- shoe case occupying a prominent position in the central area. Apart from this general collection, there will be found on the same floor a few mineral specimens, which have been isolated on account cither of their size or of some special interest attaching to thom. As each specimen is dietinctly labelled, and moreover as a special catalogue of the minerals is published, it will only be necessary in the present guide to give such a popular description 6f the collection as shaU render it intelligible and interesting to the general visitor.

The Bo-oalled non-metaUie mineraU occupy the central horse-shoe iiasG, Bud ore described at 121 ; while the Ores or MetaUifertnu TiwiwraU are placed in the series of wall-oases, and arranged in the following order : —

- British ores (west side} - - Cases 1 to 14, p. 79. British ores (east side) - - „ 43 „ 56, „ 106. Foreign ores - - - - „ 15 „ 23, „ 87. Colonial minerals - - ,. 37 „ 43, ,, 101. Mineral veins - - - „ 24 „ 86, .„ 97. Bach of these sections of the collection will now be brought sepa- rately under notice.

BitlTISH OBES. latBivuhn. "Western Side. Wall-cases 1 to 14,

COPPEB. Case 1.' — Although there is evidence that copper ores wero worked in Anglesey by the itoraaiis, yet the copper mines of this country are not aa a rule of ancient date. In the time of Elizabeth there was an Act of Parliament forbidding the exportation of calamine, ae retaining it may occasion large qtmitities oj rough eopper io fie brought in for the manufacture of brass, latten, bell-metal, pan-motal, and shrof-motal. A century since, several tin mines were absBdoned when the miners came to the yoUowB; this was the vellow copper ore; and their saying was that the "yellows out out the tin." This shows the small estimation in which copper ore was then held. In 1874 there were in Oomwall and Devon abont 93 mines selling copper ore at the public sales — "tichengs." These are so called from the circamstance that the Bale is conducted in silence ; the ore for sale is annonnced, and the bidders write the price offffl- on a Ufliet. which is folded up and silently put into o glass. The ( of 010 iiekitiixgs opens these and proclaims who is the hvh-it U4As.

The BcconntH of these sales are published in " ticketing papers,* The Talue of all the oree has been previmiBly determined bvtlia' asay of sijfliyfos, one poond in weight, which ere taken by all th6 parties concerned from the heaps prepared for sale at the mine.

The eeriea of copper-producing minerals exhibited in this colloo. ticm commences with the valuable Nalive, vir/jin. or viaihabl ropper. In mnny of the Cornish mines this mineral ia not nnfteqaeDtly found in company with variona copper ores; the largeat massH occurring in the serpentine of the Lizard district, of which a magni- ficent example will be seen in the hal! (No. 175, p. 471. The Irisi and Scotch apecimcns on the top shelf of cnse 1 show its oconrrence in. thin platee in the fissures of trap-rock ; whilst many other ei- amples in the same cose exhibit the characters of the crystallized Tftrtetiea.

From native copper wo pass to the snb oxide known as CvjprUe or rerf copper ore, a mmeral containing nearly 90 per cent, of coppM. It occura often in octabedral or eight-sided* cryatala, of a fine ruby colour and high lustre, and occasionally assumes delicate capillary or hflir-like forms, known to the minor as " plimh copper ore," and bo the mineralogist aa Ghalcutrkhite ; whilst the less pure brick-red mSftaive varietioa of cuprite are often distingaiahed as tile ore. Mela- eonite or black oxide of copper, ia a doll blackish mineral sabafcanoe Tflsnlting fVom the decomposition of other copper ores.

Case 2. — Well known froni its employm.ent aometirae. for ama- mental pnrposea, and sometimes as a pigment, tbe beaatiful minerri called mal'tcliife or ffreen carbonate of copper, naturally claims atten- tion. In this country it is found only in subordinate qnimtity, rarely presenting distinct crystalline forms, but occurring nsnally in mammillated, botryoidal, and stalactitio masses. Ita recent for- mation is well illustrated by the specimens from Wheal Leisure, in which particles of sand are cemented by this mineral. With these apecimens may be noticed the examples of capriferons sandstone and conglomerate from the Lower Keuper of the ncighbonrhood of Alderley Edge in Cheahire. Tbe copper is dissolved out by treating the sandstone with hydrochloric acid, and from the aolution of chloride of copper thus obtained the metal is precipitated by scrap iron. Among the carhonatee of copper will be found a few apeci- mena of JriiWio or Hue maiacMe, and on the same shelf are some samples of Chryeocolla, or hydrous silicate of copper,

Among the Oomish arseniates of copper, attention may be directed to the beautiful aky-blae ootahedrona of Liroconite ; tho dark blackiBh- green cryatala of Clinoclase; the bright emerald-green sis-sided

Slates of Gopper-miea; the dull green crystals of Oitesnite, and tha brons variety of the same species kuown, from ita structure, as wood arsniaie of cojtp. The aondiirHie of Dr. Paraday appears to be an impure cupro arsenide. With these are asBOciatod some specimens of JAbetheaite, or phosphate of copper, and a aamnle of tha basic anlphftte of copper hara Cornwall, described by Profesaor Maakelyne in 1864, under the name of iaiijte. Here alao will be found apecimens of Professor Church's Woodioafdite, an uncryataUizBd mineral of fine blue colour containing sulphate of copper and hydrate of alumina.

From these somewhat rare minerals we turn to the important ore known as Copper gJanee, vitreous copper, or Bednitlnte, a dianlphide of copper containing 80 per cent, of metal. From St. Ires and St. Just several fine crystallieed apecimens are exhibited, and in some of them will he recognized the pconliar six-sided forma which have suggested the popular name of " nail-head copper ore." The ape ci-

mens tmder the glnae ah&de, recently obtained irom St. Ives, are especially noteworthy.

Casea S, 4, 5, 9.— Far esoeeding all other copper orea in its im- portance to thia country ia the well-known copper pyrite*,— the yellotr tire of the miner, and the Ckdlcoptle or To uiaiiite of the mineralogiat. This mineral, which is & Bulpnide of iron and copper, is nsnally found massivo, but it ocoaaionally occurs crystaliized, its character- istic forma being well shown by the specimens in Cases 3 and 4. The fine matnmillated and botryoiaal maasea from Cornwall and Devon are known to the niinara as " blislerore "; whilst the iridescent tarnish on the surface of other Torieties of copper pyrites has suggested the name of "peacoch ore."

In this country copper ore is obtained from the minos of Cornwall and Devonshire, from some mines in Iieland, a few in Wales, and some ia the northern conntiee. Each of these loc.ilities has its I'e- presentativea in the collection, and tlio produce of the several laines will be found in the " Mineral Statistica" compiled by the author of this Guide,

Case 7. — Allied in Qhemioal composition to copper pyrites, with which, indeed, it was long confounded, is the species called Bornite, rple copper ore, or eruheKnile. To our Cornish miners the miaoral IS commonly known as " lioraeJheh ore," whilst fretjuently it passes nnder its (Jerman name of Buittkup/ern {variegated copper ore). In addition to the fine purple masses ii'om Ireland and Comwull, there will be found aeveral crystallized specimens exhibiting ita cubic forms ; these crystalliaed varieties are eiclusively British, being confined to the mines in the neighbom'hood of Redruth.

The crystalliBed specimens of the rare Cornish miuerat Teiinantile —ft BulpMde of copper, iron, and ftrsenic, of somewhat tare occur- rence — are followed oy those of Fahlerz, or grtiy copper ore, a species which, although uncommon in this country, occurs near Liskeard in fine oiTstals, which exhibit well the characteristic tetrahedral forms which have gained for tUa mineral the name of Tetrakedrilc. The aeries of copper ores is brought to a conclusion by the HpeoimenB of EwieliUmiU! or iowmowte, an autimonial sulphide of copper and lead, of which some magnificent crystals of weU-deflned rhombic form, and remarkably high lustre, are exhibited from Liskeard in East Cornwall.

Tis.

Case 8. — -IVom the earliest recorded times Britain has been famous for its tin. From Cornwall the Phtenician navigators took this metal to Tyre and Sidon ; and, in all probability, the bronzes of Assyria and of Egypt were made with the tin raised by the ancient Britons. The Cassiteridea, or Tin islands of tie historian, have been thought to be the Scilly islands; hnt as there is no evidence that any tin was ever fonnd in SciUy, and certainly there is none there at present, thia idea must be relinquished. In all probability the name was given by the early navigators to the western part of England, over whi!h the tin formations are spread, and where we find evidences of mine-workings of the highest antiquity.

Diodorna Siculns describes the trade with C9wall, " Bolerion," for tin, and mentions the place of shipment, — the Iclia, an inland adjoining to Britain. He says, "It ia something peculiar that happens to the islands in these parts, lying between Europe and Britain ; for at full-tide, the intervening passage being overflowed, they appear islands ; but when the sea returns a apace ia left dry, and they are aeen as peninsulas." Mr, Wright and the late Sis G . G . \jWKSa 40333.

vmSoS.

gnppoae tho Isle of Wight to Iw the Ictis, but it doea not fulfil any of the conditioiiB of the geographer ; wlicixiaa St. Michael's Moimt ttad, Looe Island in respecta agree with the doBCription. diodohis eviilontlj apeaka of mora than oDe island, and there is abnndwit evidence to show that both St, Miohaal's Mount and Looe Island wonld have been convenient shipping porta for the tin raised aroUnd the Mount's Bay and Land's Knd, and for that obtained from the old tin mines around 6t. Analell.

Tho produce of tin in Cornwall, for mora than a oentnry, ob- served a remarkable constancy. In 1750 abont 2,000 tons wwe pro- duced; this rose to above 3,000 in 1817 1 to more than 4,000 tons in 1827 ; and it oaciUated between 3,000 and 4,000 until 1841, In 1874 the quantity of tin ore OT"hlack (in" raised amounted to 14,716 tons, producing 9,724 tona of metallic or " wkiie tin," In. epite, however, of this high produce, British tin mining is at present in a moat nnsatiBftictory condition, owing in great measure to the recmt discoveriefl of enormous deposits of tin ore in Australia.

Tin is almost eiolusively obtained from Casaiteribi or tinUni peroxide of tin containing nearly 80 por oent. of motal. In ttie granite and clay-slate of Cornwall and Westi Devon this mineral occurs in veins, and is readily separated from its gangue and from most of ito aocompaimng minerals, by taking advantage of the great density of the ore. With the apeoimens of tin-stone will be foMd tv very cnrionB set of pseudomorphons cryatala, or those which have the composition of one mineral and tho form of another, in which the original felspar of a porphyritic granite has been removed, and the oxide of tin htm taken its place, preserving still the true fpar form. The subject will again be referred to at p. 100.

During the lapse of long geological periods the stannifajona Dt tin-bearing rocks have been worn down by the combined inilnenees of air and water, and the contents of the mineral lodes have beep carried down to the lower grounds, and arranged in obedience to the laws of gravitation. Tin was thus deposited in beds tjver the underlying rocka in the valleys, being covered up to various depths with lighter matter. Specimens of such eiremn tin are exhibited from several Cornish localities, and with them we some esamplea of the fibrous varieties of tin-stone; known from their peculiar BtrmrtFore as " iimod tin," and toad'e-eya Un." " Streaming,'' or washing these deposits for tin, is now nearly eirtittct.

Case 9. — On the first shelt of this case are placed several samples of Stannine, known also as tin pijrites ajid bdlmetal ore; a mineral containing sulphur, tin, copper, iron, and frequently zinc. Thil mineral is conlined in Cornwall to a few localities, where it has been raised as a tin ore to a limited extent.

Bismuth.

Case 9.— This metal, which occurs usually in a native or free state, is not fonnd in this country in any considerable quantity. In Com* wall ite ores ocoasionally occur associated with other minerals, — with tin in St. Just, and with copper in Bedruth and in the Camborne . mines. A small quantity is raised at East Pool Mine.

In addition to the samples of Native bismuth, of which some are remarkable for their brilliant lustre, will be found several specimens of Biawmitlihie, a tersnlphide of bismuth ; and of the rare mineral called Aiheniie at -needle ore, a sulphide of bismuth, copper, and lead. It is noticeable that bismuth and its ores ore oharactorized by their extreme fasibility, melting readily even in tho flame of a candle.

COHiil AND JTlCK£L.

HSbo 9.— The ores of these allied metola will be more flilly noticed among the foreign niiuerals. In thla country they are accaeionally found in Coj-nwall, Oumberland, aod Scotland, bad the amonnt ie neither considerable nor conatflnt. Cobalt was formerly raiaed at HuqI Sparnon, near Eedruth, and at Dolooath, near Camborne ; it has also been diacoTored in St. Juat, to the west of Penzance, and has for Bome yeara been sold from the St. Anstell Conaola. At Ooniaton, in Cumberland, fine apeeimens of cobalt ore occur ; and from the properly of tlie Duke of Argyle, in Argyleahiro. nickeli- ferons pyrites in some quantity was raised a few years einco, In 1854 the St. Austell Conaola sold no less than 79 tons of nickel and cobalt ore, bat at present neither of the minerals is raised.

The principal cobalt ores are Smaltine, or tin-white cobalt, and Cdbaltliie, or silver-irhite cobalt ; tho former an arBeiiide, and the latter an ai'senio-aulpbide of cobalt, bat both uanally containing varying proportions of other metala. The decampoaition of these areenical cobalt ores produces the peach-blossom coloured arseniate known as Erythrine or cdball Jjloom.

Among the nickel oree, of which the priuoipal is the di-araenide known as Kapfemtckel or copper , attention may be direct to the dehcate needle-like crystaia of MUlBrlteor eaptHary pyrileg,a, enlpbido of nickel occurring in tho cavities of the clay-ironstone nodalea of Sooth Wales.

Tongsten.

Case 8 — This metal, known also as wolframtwn, occura oduiiUy as a double tongatate of iron and mwiganeae, forming the apeciea called Wolfrim. Having a density corresponding' nearly with that of tin-stone, it ia with difficulty separated from the tm ore mth which it is almost iovariably asaociated. Oxland'a procosu for dressing tin ores containing wolfram will be aubaequenlly noticed (p. 112). 32 tons of wolfram were raised at East Pool Mine in 1874, The yellow mineral called Wol/ramAne ia a tnngaten, ochre ; whilst the rare species Salieelite is a tungstate of lime.

Caaea 10 and 11 are occupied by metjiJlurgical products which will be noticed onder the head of " Tin smelting " (p. 112).

ZiBC OaEs,

Case 12. — The most widely-diffused ore of this motai is the sulphide called Ziiie blende, from the Gennan Ihnden, to daaale, in allusion, to the high Inatre which this species often presents, aad which is well seen on the cleavage -faces of acme of tho specimens here exhibited. Blende is generally aasooiated with the ores of lead, Bfi'l frequently with those of copper and tin.- In a state of parity it is tranajftixent and almoat colourless, as seen in some of the specimens inthiaoMe; but generally the, blende of this country ia mixed with a variable amoont of sulphide of iron, which imparts to it a dark colour, whence it is called by the English miners Blaek Jack. In some diatriota the presence of zinc is deemed by tho miners nn- favourable, and they speak of " Black Jack cutting out the lode." In others it ia thonght tO' be a fevourable indication, and wa often hear that " Black Jack rides a good horse."

More valuable as an ore, but less abundant than tho sulphide, is the carbonate of zinc known usually as eulamino. This mineral rarely ocoura crystalliaed, but ia neually found in dejioeitB of mammillated, botryoidal, and stalnctitic forjas, of which some fine examples ui'e eniibited from Alston Moor.

THE PKmCIPAI PLOOH.

The hydrous silicate of zinc, knovm as Smitlieoiuie or cledric cala- mine, commonly occqtb associated with the carbonate, with which it is not nnfrequently confounded. Attention may be directed to a fine specimen of a bloe onpreons variety of this species from Cara- berland.

Case 12.— "With the ores of zinc wiU be found some epecimena of the rare and eiolUHiTely Scotch minonil Greenoeleite, a aolphide of eadmiitm occurring in yellow Instrous cryatala of hexagonal form. The usual sources of cadmium and its applications have been noticed at p. 77.

MANGiSESE.

Case 13. — Although not occurring in this country in ragnkr depoeite or in very considerable quantity, the ores of manganeBe have, however, been worked in several localities, especially at Lifton, near Tavistock, and at Lannceston, at Beveral minea not far from Exeter, in the Mendip hills, and in Warwickshire.

In 187-1 the mines of Cornwall, Devon, and Cardiganshire yielded S,778 tons of manganese ore.

Manganese ia employed in glasa mannfactiu'e as a decolowing agent, m the majmfBctiire of pottery aa a pigment, and it is likewise used in the manufacture of Spiegelcisen ; but its great ase is in the preparation of chloride of hme and in bleaching eatabtishmenl ; it 13 employed in hoth cases for the purpose of liberating the chlorine from the hydrochloric acid or the salt (chloride of sodinm) with which it is mixed for this purpose.

Fyrohttite, or binoside of manganese, has received its name Irora ir5(i ) fire, and X" (lu6j to wash, in allusion to its employment as a deoolonring agent in glass manafacture, and for the same reason it is called by the French' glass makers le lavon des verriere.

Manganile, or grey inanqaneae ore, is a hydrous seaqnioxide, of much rarer occurrence in tnia country than pyrolasite ; whilst the somewhat ill-defined epeoies Psihmelane is an impure hydrous oxide, usually found in botryoida! or atalactitio forms, which from their smoath surface and llofk colour have given the name to this species.

Uranidm.

Case IS. — -Of this rare metal several ores are here eshibited. The oxide called PifjMlende is interesting as being the mineral in which uranium was first detected ; whilst the species called Chalcolite and wanite are attractive by the brilliant colours of their crystals; the former of these minerals contains phosphate of copper, and the latter phosphate of lime, associated in both cases with a phosphate of

TiriHiuM.

Case 13. — In the hearths of some of the iron furnaces of South "Wales, and elsewhere, there are frequently found beautiful crystals of a peculiar compound of titanium derived from tho ores with which the fomacoa are fed (sei! p. 73). Bnt although recent researches have shown that titanium is a metal much more widely diffused than was formerly supposed, the distinct native com- pounds of this element are, nevertheless, far from numerous, In

r BRnram oum. 88

the state of oxide, titauium occurs in tliree totally diatinct fonus, of which specimens axe here exhibited. The long prisma gf JtutUa z-nnning tSrough the quartz of Perthshire, the fiao tabular 017s- taJB of Brookiie, associated with al bite- felspar, near Tremadoc, and the small pyramidal crystals of Analaae, are simply difforont forma of the same oxide of titanium 1 the chemical composition being in all cases identical.

Titanium has been employed for improving the quality of iron and steel, and for the preparation of certain pigments.

Vanatidm.

Case 13. — The yanadiate of lead called Vmiadinile, fonnd not nnfrequently in the lead mines of Wanlock Head in Dumfriesshire, will be again noticed among the lead ores (p. 108). Vanadium has been found in the copper- bearing sandstone of Alderley Edge iu Cheshire, and appears indeed to enjoy a much wider didiision thaa was formerly supposed.

Moltbdbsum.

Case 13, — The chief source of this rare meta! is tl mineral called Molyhdemto, a sulphide of molybdenum, somowhat resembling plumbago in appearance. Specimens are exbibitcd from PortliBhire, and from the syenitic rocks of Churnwood Forest in Leicestershire.

Chhomittij. Case IS. — This metal is tolerably abundant in the form of chro- mate of iron, constituting the mineral called Chromite or chrome iron ore. It usnally occurs in serpentinona rocks, and is especiaily abundant ia the serpentine of the Shetland Isles, which has yielded seyeral of the specimens here exhibited. The compounds of chro- mium are extensiTely employed in the arts, principally in the preparation of pigments.

Astiiioht.

Case 14.— At one period considerable quantities of antimony ore were raised in Cornwall, and some in Dumfriesahire ; bat now the principal part of onr supply of antimony is from Borneo and the East Ijidies.

The chief ore is the tersulphide of antimony, called indifferently AntvMOiiite, eiibnite, and aiiUiiumij glance. By the side of the samples of this ore are a few specimens of Jamesonite, a sulphide of antimony and lead, of which enormous lodes occur in Devonshire ; but the difficully of separating the lead and antimony from each other renders them valueless.

By the deuompoaition of jamesonite is produced the yellow anti- moniate of lead called Bh'miere.

BsiTisa Gold.

Case 13. — There is no metal found more widely diffused than gold, but it has rarely been found in these islands in snfBcient . quantities to render the search for it remunerative.

In the tin streams of Cornwall gold has been and ia still found. The streamers occasionally detect small particles of gold associated with the tin ore, which they pick out and preserve in a quill. Occa- sionally a moderate-sized piece of gold has been discovered. One fine specimen from Camon stream is in this collection, and also Bome of the emaUer grains. Gfold has been fonnd in Devonshire, near TTorth Moltou, and attempts have been made from time to time

86 THE PBUfCIPAL ftOOB.

to work mines Buppoaeil to produce it. In every anch attempt, however, the roHult has been the total loBS of the money invested.

There is ahnndfttit evidence to show that the Rom&ne actually worked gold in Walea ; and Carmarthenshire and OardiganBhJre have at various times yielded emalJ qnantitieB of the precioae metal. During the last quarter of a century, however, public attention has, from time to time, been directed to the gold-bearing diatriot of Merionethshire. The excitement which a few years back attended the workings at the Vigra and Clogau, between Dolgelly and BttP- mouth, led to the opening up of numeroiis other gold mines in adjacent districts, bnt the operations were ultimately aband<Clned as unremunerative. In 1874, however, workings at the Vigra boA Ologau were ro-opened, and 385 oza. of gold were raised. The gold-miniog was at one time prosecuted with vigour th61 in 1802 the Weleih hills yielded, according to official returns, as as 5,399 onncea of gold, valued at 20,390L

Among the specimens in the cose before us are several examples of native gold from 'Wicklow, the discovery of which in the last' century prodaced considerable excitement.

In 1796 lompB of pnre gold were picked up in a valley on the flank of the mountain called Croghan Ejnabela; and as the natural ConBecjuence of such a discovery, crowds of the coimtry people quitted their ordinary avocations and rushed to the gold streams of Wicklow. During six weeks some hundreds of gold seekera appear to have collected a considerable quantity of the precions metal. Then a commission, consisting of Messrs, Mills, King, and Weaver, directed the operations of streamiug, and until the outbreak of the rebellion in May 1798, the works appear to have been romunerative, "When in 1801 these works were again brought into active operation, not only was the process of "streaming still pursue bat an attempt was made to discover the lodes from which the gold had been derived. A level was driven 178 fathoms into the heart of the mountain, and the nosleaning* trenches were dug for thonsMida of fathoms in length, yet not a particle of gold I'ji situ ever rewarded this patient labour. The operations were for some time oontimied on the alluvial deposits. Having raised 944 ounces of gold, tba ingots from which were from 21| to 27J carats fine, the aJloy beinf silver, andthetotal value being 3,675i,, the Government were adviaefl to abandon the works. — On the Mines of Wickhw and Weafori,l>y Wariiiglon W. BmiOi, MA., e.

Gold has also been found and worked from a very early periid in' Scotland. Scotch gold is mentioned as early as the year 1125 in a grant made by King David I, ; and Pennant says : " In the reigs of James IV, and V. of Scotland, vast wealth was procured in tie' Lead Hills, from the gold fonnd in the aanda washed from fiie monntains; in the reign of the latter not less than to the value of 300,000i. sterling." This is evidently the exaggerated report of Bome parties who were desirous in Pennant's time, as they have been since, of reviving the search. The Bannatyne Club published in 1825 a cnrions manuBcript, " The Dheouveiie and Hielmie of (S*' Oolil Mynes in Scotland, written m ike yearl619, 61/ Stephen Athineon,". of which a copy is in the Ubiry of the Institution. In this work several diatricte are named over which gold has been discovered,''

' Coeleaning, bom the old Cornish collias-alean, fallen or dropped tin. IT

direction of these lodes.

lisiiifies to sink pits in the search of lodes transversely lo tlie suppWE "these lodes, -

Foreign Ores. 87

and many statementB, evidently the coLggerated dream of a eanine projector, are mode to conviiicB the King, who ia compared to King Solomon for wisdom, that public money might be spent with advan- tage in the search. Gold is still found m the Crawford Moor district, and an interesting speoimen of auriferoua qaaxta was discovered at Wanlookhead in Damfrieaahire in 1872.

In 1867 pnhtic attention was directed to the occurrenoe of gold in Satherland, and considerable excitement prevailed during the sno- ceeding two or three years. Large nomberH of nunerswero attracted to the diggings, and in 1868 as much as 377 ounces of gold were returned from Helmsdale. The value of this gold was about 2,000 i bnt the yield was not kept up, and the workings were soon, abandoned. Several specimenB of Sutherland gold arc exhibited, and with them is placed a model of a nngget weighing 2 oza. 17 . found at Kil-Donnan in April 1869.

SiLTEB.

Case 13. — Silvra- ores do not occur in any large quantity in this country. True, we obtain annually a large amount of silver from onr lecid ores, but this will be noticed In a future section (p. 116).

Native eHuer, sQmer glance, red siloer om, and Iwm ther are ex- hibited from several of our Cornish mines, bnt it seems deairablo to defer notice of these minerals until describing the more typical epeoimens from foreign locahtiea (p. 93).

A scries of ores is exhibited" from the little isle of Sark, where silver mines were for somo time worked ; but not being sufficiently remunerative, the operations were at length discontinued.

Absekio.

Ooae 13.— In the lower part of this case are several apeoimens of Higpickel or D/rtemcal iron, pyrites, an arsenio-Bulphide of iron frequently found in our western mines, and commonly employed as a source of "white arBonic," the preparation of which will be Bubseqaently described, (fiee p. 115.)

"With this series terminates tho first division of the British ores, the remaining section, — including the ores of lead and iron,- — being arranged in the recesses on the opposite side of tho room. As, however, it appears desirabla to continue the description of the wall-cases in their natural sequence, the collection of foreign ores oconpring tho cases adjacent to those just described will now be brought under notice, whilst the description of the second division of British metallic minerals will be rosorfed nntO reaching the opposite side of the Mueenm. (3ee p. 106.)

FOEEIGN OBES. "Wall-caBes 15 to 23.

Coppeb.

Caae 15.— Among the specimens of Natlm copper which head the series of copper-bearing minerals, attention may bo especially directed to the fine samples from the remarkable deposits armmd Lake Superior. There esiata abundant evidence to show that these deposits were worked at a vei remote period ; and one of the stone hammers used by the primitive miners will be found in Case 15. All tradition, however, of these early workings had been lost, and s of the metal was known only by the occurrence of

SCtPXH IXOOB.

raasBM of cojiper on the shares of the lake. In 1845 operationfl wk commenced at the Cliff Mine, and these wore rapidly followed by the opening up of itumerouB other workings. The copper-luids on the HOttth aide of the lake, — inolnding the Keeweenaw Point, Portage, end Ontonagon district,— conaist of Lower Silurian sand- Btonee BJkd conglomerates, with a central l)elt of trap-rocke traversed by copper- bearing veina. The raetal is also found disaeauiiisted tbrongb the beds of trap, and occasionally through the eandatonea aud conglomerateB ; and it likewise occora in contact depoaite between the trap and the neighbouring rooks. The chief portion of the copper ie native, and occaeionaliy, from the manner in which this is mixed with quartz and carbonate of lime, lorge maesee ai broken out with tolerable ease ; but when, as ia frequently the case, a TUBAS of Heveral feet in thickness presents itself, there la no mode of extricating it from the rock but by the alow process of outtiog it with cold chisels. This native copper contains a considerable pro- portion of silver ; in some Bpecimena the silver crystallizes about the copper in a very beautiful manner. The two metals do not in . general occur alloyed with each other, but the silver is scattered through the copper in such a manner that each metal r chemically distinct from the other. '" Copper also occurs at the Lake Super silicate, sulphide, and arsenide.

While studying the specimens in the case before us, attention should a3so be directed to a series from this locality preaented by Mr. Banerman, and placed in case 36.

In addition to the Lake Superior series, there are exhibited other apecimeris of native copper, from the mines of Eossia, Tuscany, Cuba, and Chile ; whilst of the valuable ore Cuprife or red ocide 0/ copper, samples are exhibited from several localitiea in Bussia, oiul from Rhenish Prussia, Hungary, Cuba, and South America, The detached crystals of cuprite from old workings at Cheasy, near Lyons, are notable for their large size and perfect form, but the mineral is disguised by a thin coating of green carbonate.

Caae 18. — The greater pai't of this case is occupied by specimens of the beautiful mineral Malachite or green carhmiah of copper, of which the celebrated Russian deposits have contributed numerous fine examples. The richest masses of malachite have been found about 100 miles south of Bogoslovsk. Some idea of the magnitude of the masses in which malachite sometimes occurs may be fornled from Sir B. Murchison's account of a lump discovered at 2fijny Tagilst, at a depth of 280 feet : — " The strings of green copper ore occurring at intervals were followed downwards, when, increasing in width and value, they were found to terminate at the base of tbe present mines in an immense ii't'cular-sbaped botryoldal maas of solid malachite, the base of which had not been reached." The summit of this mass is described aa hein 18 feet long and 9 feet wide. When Murcbtson visited it in 1843, it was calculated to con- tain not less than half a million of pounds weight of pure and solid malachite. On the formation of this malachite Murchison has some appropriate remarks, which apply with equal force to the carbonates of oopper that occur in South Australia ;—

" The geological interest attached to this mass (the above named) lies in the indication it affords, that the substance called malachite lias been formed hy a cupriferous solution which has successively deposited its residue in a stalagmitic form. Mutatis vfutandie, thia mass has only to bo viewed as formed of calcareous spar, and it presents every one of the features so well known to those who have

FOBEIQl? OBS&

exaTained atalactilic grottoeK, vi'iijh their stalngmitic floors, in tbo clefta and cavema of limestone, or still more those large mosses of ttifa, which have proceeded from, caloardoua wolts. Whenever a portion of the maltichtt has been broken off, the interior is seen to consist of a nnmber of flne laminaa (a faacioitlua of radio- Dune entric globules), which inyariablj ai-range themBelieH equally around the centre on which they have been formed, and ai'e adapted to every sinnosity of the pre-existing layer ; hare preseutiiig a dark line — there a bright and light one, just as the solution of tfae moment, the day or the honr, happened to he more or leas impregnated with colouring matter. Besides round ooncretions, sometimeB aliaosb spherical, and also depressions of the surface, the under sides of this malachite are singularly analogous to that of any largo mass of calcareous tufa, in presentiug pendant finger-shaped BtalBctitcs, which are also composed of concentric laminic. The external aui*- faces of these concretions are frequently covered with a black ore of manganese, which usuaUy falls off on being touched On flie whole we are disposed to view it aa having resulted from co)iper Bolntions emanating from all the porous, loose, surrounding mass; and which, trickling through it to tbo lowest cavity upon the subjacent rock, have in a series of ages produced this wouderfut Bubterranean iucr natation." — Tlie Geology of Mttssia, p. 374.

Passing from the green to the blue earwnate of eopper, attention may be invited to the groups of finely-formed brilliant crystals from the now exhausted copper mines of Chessy, abont 20 miles N.W. of Lyons ; from this famous locality the species has received the name of CKeaaylitn.

The dark blackish- green crystals of LUethettiie, a hydrous phos- phate of copper, and tbe bright emerald-green Euchroile, a hydrous orseniate of copper, both from Libethen in Hungary, are placed by the side of some fine mammiliated specimens of the cupreous phos- phate called Wdite, and a sample of the rare Hussion mineral lienii- aoviie, a siliceous phoephate of copper.

The mineral called AlacamUe, from the desert of Atocama between Peru and Chile, ia on oxychloride of copper occasionally found in. snffioient quantity to be worked ag an oi'e, and occurring also aa a volcanic product on cei-tain Vesuvian lavas.

In the lower part of this cose are some fine apccimens of Cqpjier glcmee and bortiile or purple copper ore, from the remarkable deposits of Monte Catini in Tuscany. These minerals occur, with othei- copper ores, in the form of nodules and irregular masses embedded in a steatitic matrix in a dyke of tertiary serpentine, or (jubbro verde associated with the metamoi'phic rock called gahljro rosso. The principal part of the ores from the prosperous mine of Monte Catini 18 smelted at Biiglia, near Prato.

Cose 17. — On the upper shelves of this case are examples of Cojyjer glance and purple ore h'om various localities, the fine masses of purple copper from Onile being] especially noteworthy. A large sample of bomite from Greenland ia placed in the hall. No. 31.

The important German deposit of Kwp/erchiefsr, or copper-slate, is represented by several apeoimena. This remarkable stratum lying at tbe base of the Zechstem, or magneaian limestone, extends naiu- torruptedly over a very wide area, and in spite of its thinness and its

Siverty of ore is sucoeJisRilly worked at several points, especially at anafeld in Prussian Saxony. Occasionally the cupreous acbist contains the fossil remains of Permian fish, and a fine specimen of , one of the most common species of PalaiOHiious ia here eshibited. The metallurgical treatment of the Enpfcrschiefer will be subse- quently noticed. {See p. 111.)

Case 18, — The Bories of iron ores commences with several apeoi- ineaa at Magnetite, ormfupietie iron ore, from the billa of Blagodat in the North UraJ ; but the most intereating aamplea of this m.!neral fire those from the famous iron mines of Sweden. " The region of the mines " — so called in Sweden — occupies the whole breadth of the country from the bonndftry of Norway to the Golf of Bothnia, ifa northern bonndaiy being a line drawn from Glommcn through Lake Liljan to Soderham, its southern bonndary lying about Int. 69°N. The area of this district is 1(1,000 square niileB. The best iron is obtained from the Dannemora mineBinUpsalftLin, of which upwards of 3,000 toas are an nuftlly received into England, and employed at Sheffield and other places for making steel. The Dannemora m.ine8 are three in number, very distinct and parallel to each other i Uioy are explored through a of more" than 1,500 yards, and to a depth of abont 80 yards. The annual produce of the Dannemora mines is aljout 35 ,000 tons of ore. Por a description of Swedish iron- smelting, see p. 60.

The aeries of iron ores is interrupted by a small number of ft'iantwM minerals, among which may be noticed the unusnally large orystalfl of S/utUe irom the United States ; the splendid crystal of Arftannte, a variety of Broohite from Arkansas, TT.S. ; and little square octahedra of Anataee from the Grisons. Some fine orygtala of apJiene, a ailicate of lime and titanium, btb also worthy of notice.

Returning to the iron.pi-oducing minerals, wo find several shelveB ooonpied by examples of the different varieties of ScemaUiB or red inn ore. Araono; these the eye will be especially attracted by the brilliant lustre, and m many cases by the iridescent tarnish, of the crystal- lized variety called spetyalar iron ora, of which the Isle of Elba has contributed some beautiful esamplea. The Elban speonlar ore, cele- brated from remote antiquity, occurs in enormous deposits on the eastern side of the island, where it has long been worked by large open excavations, principally at Eio ; whilst the rich veins oimag- netie ore assoeiated with hematite at the famous Loadstone Moun- tain, or Monte Calamita, have recently invited esploration. The occurrence of eoalar iron ore in the craters of volcanoes has been noticed at p. 68.

Case 19.— JriiJioMito, irowii iron ore or hydrous peroxide of ism, occasionally called " brown Jiceimafile," is a very abundant and widely- ' diffused mineral, resulting frequently from the decomposition of other iron ores, and often associated with the ores of manganese. The fine stalaetitic and botryoidal forms of the Enssian specimens, and the fibrous structure of many of the German samples, sufBciently show the characters of the purer varieties ; whilst the friable earthy forms paesing into ochrS are illustrated by exaniplea from various localities. The pure crystallized hydrous sesqui-oxide of iron, of definite composition, has been separated as a ffistincfc species under the name of Qiithite, a name introduced by German mineralogists in honoAu- of their great poet and philosopher.

The horj iron ore is an. iuterostiag variety of limonite formed in low marshy ground from the decomposition of other iron ores. It always contains a large proportion of impurities, phosphoric acid being often present to a considerable extent. The lalee ores of Bweien, Norway, and Finland, ore concretionary forms of brown iron ore formca at the bottom of shallow lakes, whence they are obtained by dredging.

Brown iron ore appears in many oaaea to have resulted from the alteration of the carbonate of iron, to which apeoiea we now pass.

r

Thie valuable mmeral, called i-adi{tTeat\j Spathote iron orf, eh a},ii- bite, eideriie, and scarry iron ore, frequently occnra cryatailized m rhombohedral formH, which, commonly preaent onrved faces, well aeen in the fine Bpecimen from Danphin ; whilst the large crystals from Hiittenberg in Carinthia exhibit the change of this mineral into brown, iron ore by the elimination of carbonic acid and the abaorp- tioti of oxygen and water. Immenee beds of spathose ore are foand m SWria, forming the out-er part of the Erzberg, a mountain from which it wae probably dug by the Bomane. In Carinthia an escellent ore of thia kind exiata, from which iron and eteel of the first (juality are produced. Valuable deposits of apathoae ore occur in the Devonian rocks in the neighhonrhood of Siegon in Ehenieh Pmaaia, including the celebrated Stahlberg, near Musen, where it has been worked ainee the fourteenth centnry. The carhnnatei of iron are highly valned for the production of pig-metal well auited for con- version into Bessemer steel.

The remainder of this case ia occupied liy iron ores of lees importance than thoae already mentioned. Among theae may be noticed the Elvan ailicate of iron, called Ilvaite or lievrile; the common arsenio-Bulphide of iron, or Miepidcel; and the rarer arsenide of iron, from Eeichenatein, termed Lolmgile, the treatment of which for the separation of gold will be described at p. 115. The large pentagonal dodecahedrona of Iron pyrites from Elba, and the fine bronze-oo! oared crystals of Pyrrhotine or mugnetic pyrites, fium Brazil, also deserve attention ; and these, with a small collection of OJiroine iron ores, complete the aeries.

MANQANE3E, Bismuth, &c.

Case 20. — Esamjiles of the rarer oiides of manganese called ffave- raamniU and Brminite are placed by the aide of the oxides known as Fyrolueite, Maganite, and Peilomelane (p. 84), minerals which are largely raised in Spain, NosBan, Thnringia, and the Hartz. With theae orides are grouped specimens of the pale pink carbonate of manganese called Diallogite, or manganese spav, and of the rose-red ailicate termed Bhodoniie ; whilst tna snlptidea are reproaented by samples o( Alabandine or manganese fcZciiifo, flud by a specimen of the rare mineral Haumte, from its only known locality, Kalinka in Hungary.

Mention has already been made at p. 84 or the value of certain oxides of manganese aa sources of oxygen in the operations of bleach- ing and glasa-making, for which purposes they are imported in large quantities. The manganese ores are also used ia the preparation of Spiegeleiaen, a variety of cast-iron containing manganeae, and used in the Bessemer process of ateel-making {p. 59).

The minerals of the aomewhat rare metals which follow need but slender description. A few ores of Bisrn/ath are introduced, princi- pally from the cobalt mines of Sasonj' ; and with theae are group samplea of Molybdenite from Bohemia, Greenland, and Chile : these are followed by some Saxon specimenfl of the nraninm-ore ca.lled Pitehblende, and by a sample of the pecuhar Swedish mineral known as Oertte, in which are associated the sihcat of the rare metals, cerium, lanthajiium, and didyminm.

Tiif. Case 20. — The tin ores of the continent scarcely come into compe- tition with those of our own country, but enormous quantities of tin are imported from the isles of Banca and Billiton, and from the Malay peninanla. In the small group of foreign tin ores here inter-

calated, wOl bo Tonnd some fine otyHtala of tin-atone from and several epeoimeiia from the tin mines of the Erzgebirge .. Ore MonntainB, which eeparato Sasony from Bohomia ; and with these are placed samples from Spain, RuHsia, Greenland, Brazil, and the United Statea.

Following the tin ores are some apeciniena of the tuugatate of iron and manganese, called Wolfram, a mineral with which the orea of tin are commonly associated ; and of the tnngstate of lime named ScJievlik, after the Swedish chemiat Soheele.

CosAj.T AND Nickel. Case 30.— The group of cobalt and nickel ores preaenta some inte- resting specimens, chiefly from the mines of Schneeborg in Saxonj and Tunaberg in Sweden. The white cubic cryatals of SmaUiiK, with faces frequently curred and fractured ; the pale yellow cryatalB of C(Aaitine, eshibiting compound forma allied to those of irou pyrites ; and the pink cryedalline or earthy ErythrinB, occurring &eqaeQtly as an incruatation on other ores, are the most prominent ftmon the cobalt minerala; whilst in the group of nickel ores attention may be directed to a email crystallised apecimon. offtip- femielisl, some line capillary cryatals of MiUerlte, a sample of Brhawtite or antimonial nickel, and the find emerald green incrustations ofTacogifs or carbonaU of niahol from Pennsylvania: the composition of most of theae miiierala, and the appUeationa of cobalt and nickel ores, are noticed at pp. 83 and 114.

Case 20. — The fine aeries of antimony minerals commences with some Bpeeimena of the native metal, and of its oxides — Valenilniie and SenanaiyatiU. Of the principal antimony ore, called Antimony

iiltwwe or attlmiie, numerous speciraena are exhibited from various ocalitiea ; those from Hungary being remarkable for their fine crys- talline forma, whilst the Borneo samplea are interefiting as lepre- sentatiyea of a very importaat locality. It will be observed that some of the Bpecimens axe invested with a yellow crust of oxide of anti- mony, whilst others are coated with the reddiah osysulphjde called Eermefite or antimojty bhnde, of which mineral some specimens are exhibited from Brannsdorf in Saxony, showing well the cuaracteriatio tufts of red hair-like cryatala.

Zinc.

Caae 21. — On the top shelf of this case are some fine exampleg of the exclusively American ores called iTJcife, or red oxide of zinc, and Franklinite, a mineral in which the zinc oxide is associated with the oxides of iron, and manganese, and which is valned as an ore of iron rather than of zinc. The preparation of zinc from the New- Jersey ores is illustrated in Case 4,9, whilst the production of Spiegel- eisen from the franklinite residues finds illufltration in. Caae 10 (p. 60). The New Jersey specimens are followed by a group of carbonates and silicates of zinc from the celebrated Vieille Montagne or Altenberg deposits. These mines are situated on part of the Belgian, Prnsaian, and neutral ten-itories, between the towns of Aix-la-Chapelle and Verviera. The calamine of these deposits haa been worked since 1-435 ; but for four centuries it was employed merely aa an earth to make brass, as it was not known to contain any mtal. It will be remembered that a large mass of this cala- mine stands iu the lower hall (No. 45J.

' TOBWKw oins, 93

The group of zinc oroa is brought to a close by several esamplea of Slandii, or sulphide of zinc, of which those from Hungary and Bohemia present fine cTystallioe forma, wbilet other Hpeoimens are notable ob containing Bilver.

Case 21, fuller deecription of the varioua minerale from which lead ia extracted will be given in the notice of the British series (p.l07) : the foreign specimeuB in this case before as are interesting, however, for compariBon with our own.

In the group or lead-spara attention should be directed to the fina transparent and weU-formed crystals of Angleeilc, or eulphate of lead, and of Ceruesile, or carbonate of lead, from the Wheatloy mine in PermHylvania, where they occur in the upper part of rich lead veins conraing N.E. and S.W. in gneiasoae rocke. Not must we omit notice of the remarkably brilliant cryatalH of anglesite which beatud the c&viiica in the rich galena of Monto Foni, in the island of Sardinia. Of the phoBchate of lead called Fyromorpliite there are exhibited some examples or peculiar hollow crystnls fVom the TFheatley mine, and of fine barrel-shaped cryatala from the minea of Kassau. The eye will not fail to be attracted by tho brilliant yellow cryatala of Wulfeiiite or molybdate of lead, from Utah; and here alao will be found some aonibre apecimens of the same species from tho lead minoa of CarinthiEi.

A amall group of the somewhat rare antimonio- sulphides of lead is here intercalated, incloding the species called Boulangeriie, Tlagioaite, and Geocromle; ancT from these we pass to tho moat widely diffused ore of lead — its sulphide, call Galena, of which mineral a large Hertes of sfjecimens is exhibited, fairly reproaenting the principal lead-producmg districts of the continent. France, Spain, Tnacany, Saxony, HungajT, and Russia have each contri- bnted aamplea, and wiui these Saropesm apecimens are placed a few samples from certain mines in Asia and America. The physical charactera of this abundant mineral will, perbaps, be better studied among tho more varied seriea from our own rainea (sas p. 107).

Case 22. — Silver ores have been mined for from the earliest re- corded periods of man's history. Throughout Spain, France, and Britain it is quite clear that the Eomans eagerly aearched for this metal, aa they have left behind them numerous remains of their mining and smelting operations. The silver minea of Spain were abandoned nntil within the last fort years ; within that period several rich mines of silver have been discovered. Tho silvor miaes of Mexico have been much celebrated since the conquest of that country by Cortes in 1519.

The most productive silver mines in the "World are those of America, — New Spain, Peru, Mexico, and espiecially Fotosi, as well as the names of some other places, have become almost synonymoua with those used to signify preoioua metal. The greater part of the silver extracted by mining in Pern ia found in a, species of ore locally called pncoa; it is a brown oxide of iron, with silver dissemi- nated through its masB ia exceedingly minute particlea. The ore of Chile is similar, and one vein of it, existing in the Andes, is said to have been traced for a distance of more than 90 milca, having branches running in the adjoining mountaipa, some of wbich are known to be 30 miles in length.

9i THs mRdmmstooB.

Among tlie moab remarkablo of the exiatia sUvcr mlaea those of Meal del Monls mnHt be named. Theao mines ha,vQ been con- tinnonBly workfld since 1749 ; bub long previoualy to that date eitenaive bat irregnlar workings had been carried on.

Silver mineB of es±rEiordinary value have rooently been

in the "Western States of North Americn, especially in Nevada, Oolorftdo, and Utah. Perhaps the moat important of these diecoveriea of silver ore are tboae in the State of Nevada which date from 1859. TToi-kings of enormoaa value have boen opened in the neigh- bourhood of Virginia City and at other points on the famona Ootn- Btock Lode. A model showing the locations oa Ihia lode, and in the neighbouring country, stands near the eaae of ailver ores (model No, 25, p. '65). I6 is reported that during the year ending December Slat, 1875, the Conaolidatcd Virginia Mine alone yielded bullion to the value of 17,000,000 dollars, or 3,400.000i. The metal is, however, extremely rich in gold, and it ia eatimoted that 45 per cent, of the TOlue of the bullion ia derived from this source. The Director of the United States Mint statas that the tJjtal production of all the mines on tlie Comatock Lode during the year 1875 may bo estimated at not leaa than 60,000,000 doLlara, equivalent to 10,000,OQOi. But in addition to the workings on this great lode tiiorc are important ailver mines in other parte of Nevada and in several neighbonring abates. The lateat statistics of these wosbem minea will be found in the BspOTtfTom, the select Committee oti Depraciaiion of Silvm; 1876,

Amonji the ailver minerals exhibited in the case before ns are some highly intereating specimena of the nalive metal, the fine solid maasea &om Chilo being especially noteworthy. The remarkable' association of this metal with native cupper in the Lake Suporioi specimena has ahady been noticed (p.88).

Combined with sulphur, either alone or aflaociatod with antimony or with araenic, silver forms a series of beautiful aud valuable minerals. Of tivese the ordiuary sulphide called ArgeiUUe, vitreous ore, or dloer glance, is a soft and highly malleable mineral, assnmlug a aeries of cubic forms closely related to those of galena. PaasiBg over the rare Saxon mineral Miargyriie, we may notice among the aiitimonio-sulphides of ailvor the beautiful speoios called Pyrargyrite, Tuhij btende, or dark red siln ore, of which the Mexican mines have contributed aome magnificent hexagonal ciystala ; whiliit from Saxony is exhibited a specimen of ligM red silver vre or ProuiUii, a mineral chemically difl'ering from, the last species in containing arsenic in the place of antimony. To the same ehiss of minerals beloijg Siejphanite,_ or brittle silver ore, the rare species called FirAteitdo, and the mineral known as roljKuite in which the ailver ia partifdiy replaced by copper and the sotimony by arsenic.

Another group of silver ores ia foi-med by the combination of the metal with chlorine and its allied elements. The chlorides, bromidea, and iodides of ailver ao formed, of which a few specimena are ejt. hibited from the Sonth American mines, are all affected to a greater or leaa extent by the action of light. It ia notable that iodide of silver when heated, instead of expanding, slightly contracts in .

Golt.

Caae 23.— The collection of gold ores is headed by several speci- mena from Euasia. In all probability the auriferous tracts of the Uraliaa mountains were worked over by the Scythiana ; and the Aruaaspi of Herodotus, a people who had but one eye, and who took the gold away by violeace from the Griffins, may have been, as

Humboldt BuggeBts, this nomadic peoplo. Qmeltii doscribcfi the ancient gold works which ho discovered iu the diatrict j ancl Murchiaou speake of great pilea of emoient drift or gravul which have been removed for the extraotioa of the gold.

Upon the character of the aoriferooB deposita of Bueaia Sir Bodc- Murehiaon writes {Siluria, p. 443.) : " In aomo Bpote in which the gold occnra ia a heavy clay j in others, it ia made np of - menta of quartz veina, chloritic and talooBO Bchist, and crcenatone, whidi lie upon the aides of the hillocka of eruptive roc&. It waa from the iuQUing of one of the gravelly depresaiona between those elevations, south of Miaek, that the fiLrgeat lump of solid gold was found of which, at that time (1824), there was any record." Thia " pepita " weighs 96 pounds troy, and ia alill exhibited in the MuBenm of the Snperial School of Mines at St. Petersburg. Some amoll saaploa of Siberian gold are exhibited in the caae before a.

The produce of the various gold-waahing and amalgamation works of Rnaaia appears to have been, for many years, aboat 1,500 pooda ; the Bussian pood boing equivalent to about 40 pounds troy, thia will be equal to about 60,000 pounds troy. The following estraot from the Anniveraary Diacourae of the President of the Geographical Society, Sir B. Murahison, in 1841, ie to the point; —

" In Bussia, aa to the Brazils, the great masa of the metals is derived from local detritus or alluvia, usually called gold eand, but for which (ae far as Buaaia ia concerned) the term shingle would be much more appropriate. With very trifling exceptions, all Boch auriferous detritua in the Baaaian empire occur on the eastern side of the Ural. Slightly known, and near Ekateriiihurg only, in the days of Pallas, it was not until the reigna of Paul and Alexander that these gold allavia were found to extend in a certain zone to the north and south of that locality, throughout 5° or 6° of latitude, and that eventually gold was extracted from them to the annual value of about half a million sterling. Notwithstanding the in- creased exploration of late years, and many resdarchea in the nortiiern and southern portion of this chain, this quantity has been rarely exceeded; and latterly, the alluvia in some troots being exhauated, it has begun to decrease. The reign of the Emperor Nicholas, has, however, been diatinguished by the important discovery, that portions of the great eastern regions of Siberia are highly auriferous, Tiz., in the governments of Tomsk and Teniaeik, where low ridges, similar to those on the eastern flank of the Ural, and, like them, trending from north to south, appear aa offsets ft-om the great east and west chain of the Altai, which aeparatca Siberia from China. And here it is 'curioaa to rSmark that, a very few years ngo, thia distant region did not afford a third part of the gold which the Ural produced; but, by recent reaearchea, an augmentation io rapid and extraordinary has taken place, that in the last year (1843) the eastern Siberian tracts yielded considerably upwarite of two miUionB and a quarter stsrling, raising the total gold prodnce of the Busaian empire to near three millions sterling."

A few specimens have been contributed from the American mines, and it will be remembered that a large mass of ani'ilerous quartz from the Califomian workings is placed in tho Hall (Ko. 113), and described at p,t49.

The long-worked gold mines of Hungary and Transylvania are roprosentea by specimens ftom Schemnitz, !S"agy-banja, and YOrtiBpatak.

The Gold Coast " of West Africa has long been celebrated for its gold, ajid a nugget brought from Ashantoo at iho conclusion of the late war jb here exhibited.

THE ftOsOtPU. SXOOB.

rLiTlSTM.

Case 23. — The metal platinam was first diBcovered by tJlloa, a Spanish traveller in Americ, in the year 1735. It has since been discovered in Oolnmbia, St. Domingo, Borneo, La the eands or the Bhine, Califumia, Canada East, and Ruasid.

" Thongh ores of platinuni are found in the allnTia of the Ural chain in rarious parallels of latitadc, it is only within the territories of the DemidoH' family they are still Tcorked. After an exami- nation of the greater number of the platinnm works belonging to Nijny Tagilak, all of which lip on the western slope of the Ural-tan in that parallel, M. G. Eoao has shown that in one only of the nnmeroaB musses of alluvia was any gold mixed with it, and that in no instance could be detect any veinstones of quartz, or other fragmenta of rocka, nor of magnetic iron ore, ao abundant in the gold alluvia. The platinnm had formerly, it appears, been found, for the oioat part, in fragments from the weight of a zolotnik to near one pound, though rarer examples had oecnrred of pieces weighing from three to npwarda of eight pounds. According to Eoae, the major part of the detritus associated with the platinum consists oF serpentine, with very rare appearances of hyperathene or other materials, the ground over which it has been washed being either chlorite schist or quartzoae talc achist, the latter containing diffused epidote, The platiniferoua alluvia on the west slope of Ihe Ural ridge, like the gold alluvia on the east, have in truth been drifted into adjacent depressions from the culminating peaks of hom- biendo alate, serpentine, and greenatonB, and are occasionally irom 10 to 1-2 feet thick."— ne Geotojij of BiLseia in Europe, ly Scderiek Iney Muroliieon.

For the applications of platinHm, see p. 76.

TELLTIEnTM.

Case 23. — The few minerals which contain telluriom occur, in limited qnantitiea, with the gold and antimony ores of Transylvania.

The native metal is now exceedingly rare, but half a century aince it was found in rather large quantities in Transylvania, and was molted to extract the small (jnantity of gold which it contains.

In 1782 Miiller and Reichenstein showed that the ores of tellnrinm contained a peculiar metal i Klaproth confirmed this. Sir H. Davy examined some of the oxides, but to Berzeliua we are especially indebted for our knowledge of this metal.

Case 23. — This metal is occasionally foimd native in amall globules on cinnabar or in the fisaures of the gangue, bnt the native metal nsaally contains a small proportion of silver, the amount of which sometimea riaes to a cobs iderable extent, forming the speciea called Anuam. Most of the quicksilver of commerce ia, however, ohtaineij from the aulpbide known as Oinnabar or native vermilion. In Europe the most important mines are those of Idria, in Camiola ; and Almaden, near Cordova, in Spain ; whilrt in California valuahle deposits of this ore occur at New Almaden. The metallurgical treatment of cinnabar will be noticed at p. 118.

Absekio. Case 23. — The collection of foreign ores' is brought to a close by a few arsenical minerals. Of theae the principal are the bright aurora-red bisulphide of arsenic called Sealgar, and the lemon- yellow tersulphioe known as Orpiment, of which the former is tbo

more important. Witt theas is placed a cup beautifully crvod in native realgar by the Cliineso, who hiehly esteem the mineral for its powerful medicinal properties. It has been found neoeaaiiry to protect this specimen froni the action of light and air, since th* eolid red minerftl atlier long exfiosnre diaintegratea to a yellow powder. Both the arsonicBJ Hulphides have long been employed ai pigments, but for thia pnrpoee they are nBnally prepared itrtilicially.

Wail-casoa 34 to 36.

The casea occupying the circalar or north end of this floor are devoted to the exhibition of an inatmctive aeriee of ejiecimena in- tended to illuBtrate, within aneh a space as might be oonveaiently Btndiod, mony of the conditiotis under which hoes or mineral veint occur, and the general characters which th present. For the pnrpOHeof aiding thoeewhomay not be familiar with the phenomena of mineral formationa, the follomng popular description of the more important circnmetances connected with these accumulations ia wnttiCn ; a more detailed notice will be fonnd in the remarks of Mr. Smyth in the Mineral Catalogue (p. 88 et eq.]

Jt may, indeed it does, appear to many who are familiar with our mineral dietricte that the utmost uncertainty jpreTaila in everythins associated with the proceaaes of mining. " Wliere it is, there it ia," is a hye-word among many practical miners, who thereby to express their ignorance of any general laws by which wc may be

Sided in aearch of metalliferona treaenrea. Admitting that our Dwlodge is inauf&cient to enable any one to determine whether there exist metallic ores at a considerable depth beneath our feet, in the earth's croat, by mero obaervation of the aurface, and that, conaequently, mining explorations must be to a great degree specu- lative, it ia yet certain that those mineral formatioiia are digtri~ liuted in obedience to sotae eiact laws, and that, like all natural' lawa, tlie diecovery of them is within the reach of the human mind. Observation, experiment, and thought will, no doubt, sooner or later advance man to a knowledge of the conditions npon which the accumulation of metalliferona minerals depends. In the meantime it is important, by the atady of such collections as these, that every student should famUiarize himself with the physical phenomena exhibited by the deposits within mineral lodea, and learn the con- ditions which prevail in any of those districts where subterranean explorations are carried on.

Motiel of a portion of a Mming Diatfiit in Conwall. Central Series. 3"o. 34 — By reference to this model, near Wall-caae 25, the character of mineral lodes will be understood. The two dissimilar woods are intended to illustrate the prevailing rocks — granite and kiUaa or clay slate — of that important mining county, Cornwall. The liuoa which run across these rocks are aupposed to represent mineral lod, containing either tin or copper, as shown by the different colours introduced. Jiny one imagining thia model to repreaent some square miles of country, acrosa which there has occurred extensive oraoks, either ia the process of the consolidation of the rocks, or by mechan- ical force since the period of conaolidation, will realize the facta, in the main, of our mineral-lode formations. Cracka have been formed, no matter how, in the rocka they tiHTcrHe, and these fiaaorca have 40332. G

boec ohwinela tlirough which water passed to conaidemble depUu into the crust of the earth in the process of time those fiBBuret were filled with earthy or metallic miner&ls, and probably under the inflaence of tba immeaeorable force of the crystalliBation of such masses, not only were the first fissures enlarged, bat lateral ones formed, which would eTontaally partake of the general cbaraeter of the main flssnre or lode. By the study of tfw model of tite lead mim at Nentiherry Greens, Alston Moor, No. 27, opposite Caae 30, in the county of Cmnberland, it will be seen that even in a stratified oonntiy the mineral lodes may, in like manner, be regarded as cracks ei- tending from the surface to nn unknown depth throngh the difibrent strata.

The oommon hypothosia formerly adopted wae, that the veiua were filled with matter introdnced from below, which either was injected in a state of icncous fusion, or ascended by Bublimation ; but this riew ia geueratty abandoned, very few of the i'ttots observed appealing ill any way to support it.

By some eiperimentaliBts, who have succeeded in producing arti- fically, by the agency of electricity, miniature mineral lodes, those yaluablB natural forEi8ti.0iis haie been leferred to electrical power. We must not, however, too hastily decide upon this, — the probdr bility being that a set of jdiysical forces, which are as yet only dimly Been by the eye of soience, acting on the material particles frill be found to be the causes regulating the effects under con- sideration.

It is certain that in Devon and Cornwall thro are distinct indi- cations of the iafluencee exerted by two dissimilar rocks ia producing the formation of the motalliferons minei'als. It is evident too, that a main line of direction is obsejTed by mineral lodes, and usually Uiedirection of lodes containing the ores of lead is neaily at right angles to that of the copper and tin veins in the same district, the latter coursing nearly east and west, whilst the "cross courses" and lead veins ran almost north Kud south. This is well seen in the in-odd of Sohnhueh Mine, No. 30. Again, in the lead districts of Wales and of the North of England, we find the ores of this metal commonly ocunrring in the limestone bands, and appearing only slightly, if at all, in the sandatono and shales associated with the limestone. There are, however, districts, and eatensiveoaes, inwhioh the lead occurs in the sandstone and nob In the limestone, and there are some in which the preference appears to have been given to shales. This is strikingly shown at the Grasaington and at tlie Cononloy mines. Snob facts prove to us that some conditions bayonid those which are dependent upon tbo chemical constitution of the rooks are to be songht. Indeed, tne whole snbjact is open for investigation, and ft rich harvest awaits the student of nature who may zealonriy and thonghtfnlly cultivate this estenaive and impoi-tant line of reseai'chi

Prepared by these general preliminary remarks to understand the aim of the collection, we may at once proceed to its aystematio examination. The series commences in Caao 34 with a number of specimens illustrating the formation of veins on a em.al! scale in nodnlar conOTetioiia of clay-ironstone, by the contraction which the nodules have snifered during consolidation, and the snbsoquent deposition of variona minerals in these fissures of contraction. Not only do ctirbonate of lime, quartz, hatchettine, and other non' metallic minerals occur in bucU cracks, but associated with these are found various metalhferoua minerals identical with those which form the object of exploration in metallic veins -, such, for

ia}iER4& .

inatanoG, as zinc blende, galena,, and copper pyritea. The remaindor of thia case is oocnpied by samples of niirrow siraple roina known from tboir smail breadth, aa " ala-iuga " or " threada. Some of these branches consiBt of metalliu mineml, others of non-matallic ; and some interesting spenimens are introdneed to show tha diiferences obaerrable in the character of a veinia paasuig from one rook to aaother.

The series of simple Tina is oontiniied in the succeeding Gases (Soa. 2B and 26), the Teina, however, inareOHing in width or be- coming more powei'fu!. In many specimens introdnced into this Eirt of the series it will be obserroa that the minerab inst-oad of eing gathered into strings are diatribated throagh the rocks thomselres in &n irregalar manner ; this ia epeoiallj the case with tin-stone, which! frec[uontly occurs disseminated through granitic rocka. It haa been snggeeted that in many cites the metalliferona mineral haa been aegregated or BoparaU;A from the aarronnding roDka, and acoumulated in the form of veins, the par- ticlea of a like character being drawn into these lines of aoonmnlation by some of those mysterioua moleaolor forcea which are bat little understood.

Prom the simple veins wtich, with few exceptions, liave cousistod of a single mineral only, wo jjaes in the next two Cases (27 and 28; to illnatrationa of lodes, consisting, first of two mineroU, and then of Bereral. These instrnctive exaraplea are of high practical vnlne, aa illufltrating the enhjeot of tho " paragenesis " oi miuerals, cjr IJte characteristic association of certain epeciea, — a qneation of the deepest interest alike to the mineralogist, the geologist, and the miner.

In some inatanoes the formation of the difiWent minerals baa evidently been contemporaneons, as in the fine example from the Ecton minea (No. 191), in which calo-par and oopjier pyrites have simnltaneonaly crysttd-liaed; but in other caeas the minerals have ohvionsly been formed in snooession, ftsaoeninthe fine Brazilian vein- stone (No. 203a), where we observe a sequence of quartz, dolomite, and magnetio pyritea. The association, however, is in these cases, to a certain extent, irregular, ajid it remains for ns to study in Case 89 thoae specimens in which, may be traced a definite sucoesaion of regular deposits. Thia ia strikingly illuatrated by the beaatifal HOTeimena of "riband" or "banded" veinstone from Saxony (Soa. 233 and 233), in which we notice, within a vorv limited width, a succession of alternate deposits of qniiriz, galena, heavy-spar, iron pyrites, and zinc blende, the layers being repeated with tolerable symmetry on each aide of the veinstene. Among the instructive speoinienB in this case may be noticed the fine Bohemian veinstene (No. 252), which conveys an excelleat idea of the general cltaractere of a lode ; but it is be regretted that space-does not admit of ita being placed in its natural position.

Some interesting apeoimena in the following Case (30) exhibit certain peculiarities in the auooeasion of the deposits. In niany of the examples crystals of a later-formed mineral have been deposited on particular aides only of the pre-existing mineral, the canae detHinining this elective action being iu many cases far from obvious.

Vein-depoflitB after their formation have often been snbjected to the action of certain dislocating forces, which have again established &BCtnre3, and in these new fissures other minerals have bc.>eu depo- sited, thus producing the structure called "comby" Several ex- jiraplea of comby lodes are introdnced, in which, ttus wacjiraija.OTi.'A jJateashoB's that the opening mast \is-ve\ieefl.ietaN. vm.'a&i'sR**!- at diatiBot inCervals, -

100 The Principal Floor,

The mineral deposited in R lode occaaionally eervEB to cement logetlier angnlar fragments of the ueighboaring rocks, and even of other veina. In Caae 31 is a large collection of snoh "breeeiated" lodea, in which a noii-metallie mineral has acted aa the cement ; frag- mentB of eandstone, for inatance lieiug cemented by heaTj-apart whilst Caae 83 ia devoted to (he exhibition of those in which a nwfoZ- liferous mineral has been introduced ae cement, aa when Bandstone fragmenta are bound together bj galena. In the upper part of Case 38 are some intereating brecoiaa containing fragmenta of pre-existing lodee i pieces of copper pjritfia. for instance, being embedded with Irugraente of quartz in a " flncan " or clay.

The fine pendent forma of the atalactitee, introduced in Case 33, will n&turtiUy attract attention, and it will be ob8er7ed that many of the Cornish specimens exhibit a regular sequence of deposits, the stalactite haviog been coated hy a Buccossiou of newer-deposited minerals.

The polished and striated surfaces of the " alickenaidee," in Case 34, evidently point to some alidin or grinding motion in the mass constituting the lode, affording evidence of rooTement since the liirraation of the metalliferous matter, such movement as would be sufficient to account for the fissures and breccias to which allusion has been made.

From these evidencea of mechanical disturbance in mineral lodes, we may pasa to those changes of a chemical character which veia-depOaitB irequently snffor, as especially attested by the pheno- mena of peeKdmiwrphisia. In thia caae is arranged a large collec- tion of the so-called "displacement" pseudomorphs, or thoae in which one mineral ia deposited either upon or in the place of another. Of such changes the curious "boxes" from virtuons Lady Mine, near Tavistock, are interesting examples : a coating of carbonate of iron has been deposited upon cubjo crystals, pro- bably of fluor-spar, and- by the subsequent removal of these arystala the encrusting carbonate has been left in the form of large hollow cubes, in which quartE and copper pyrites have finally crystallized. It may thus be readily onderstood how a cellular character may be imparted to a lode by the hollovrs formed on the removal of the original minerals.

The formation of certain pseudomorphs by the very gradual aub- stitution of one mineral for another has been explained in connexion with the intareBting crystals of tin-atone in the form of feJouar

In addition to tho displacem.ent and anhstitution-pseudomorphs just noticed, there is yet a third group in which the change of mineral ia readily explicable by chemical action, and of these " alteration "-roendomorphs a series is exhibited in the succeeding Caae (3B). These may result either from the addition or from the removal of a constituent, or from a partial exchange of inRrcdients. thus the crystal of calamine ia the form of a large scalenonedron of calcite has been formed hy the exchange ol' lime for oxide of zinc. So obvious in many cases ia the formation of these "epigenic" pseudomorphs that it may, to a cetain extent, be auccessfully imitated, and an interesting series of such artiflcial paendomorphs, prepared by Mr. H. C. Sorby. P.R.8., is placed in this case.. In nature, such chemical action occurs in many cases on a very extended scale, aflfecting mineral masses often of enormous extent. To illustrate these changea there is introduced into thia case a large series of minerals occuiring mostly in the upper parts of lodes, whore the original depoaitB Oflve been Bubjectwi to atmBBWric inftMeiicai. UTins the orjetak of angleaite often foimd in thie TasiflcTO -wotcctis*

COICWIAL PHOmrCTS. lUl

of a lead vein are true products of aJWration, having resulted from the absorption of oxygen by the galena forming the holy of the lode, and the consequent osidatios of the sulphide of lead to n aulphato. A very common alteration in mineral voms is illustrated by No. 33f in which large pentagonal dodecahedroos of iron pyrites are supor- flcially converted into brown iron ore, by the elimination of aniphur and the addition of oxygen and water. On the " bank" or oatcrop of a lode such ft change ia exceedingly common, the snperfioiw deposit of loose brown iron ore, which thus acta as a cap to the ore beneath, passing under the name of "milan." The greater part of the following Case (38) is devoted to Che diaplny of varied lamploe of this gossan, which, although not perhaps very attraotiro to the eye, are nevBrtheless of the highest importance to the miner, who is frequently enabled to jndge from them of the probability of cutting ore in the deeper workings.

The remainmg portion of this Case (39) is ocoapied by a coUoctloo of specimens illustrating a class of chemical changes, of a diH'erent chaiacter from those already studied. In these specimens the decom- position of certain metailio minerals has resulted in the prodnction of native metals; thus there will be found among the apecimena, crystals having the characteristic octahedral form of red oxide of copper, but consisting entirely of the native metal ; the oopper having been reduced from, its combination with oxygen ; and it is indeed probable that many of the metftla which now oocor in a native state have been reduced by successive stages from varions combinations, often of considerable compiexity.

COLOITIAL PRODUCTIONS. Wall-cases 37 to 42 on E. side.

AUSTBillA.

Caae 37. — The gold fields of Tictoria, which naturally claim priority in any notice of the mineral products of Aostralia, are re- presented by a number of specimens which from their interest are separated from the general collection, and grouped together in a special case on the western side of the room, which has been noticed in the description of the central series {eee p. 69). Second only in interest to these gold fields are the remarkable copper deposits in the neighboaring colony of Bonth Anstralia, well illuHtrated by the specimens in the ease before us. These are principally from the famous mines of Bnrra Bnrra, situated about SO miles N.B. of Adelaide. The rich deposits of carbonate of copper in the earlier workings at these mines resemble in many respects the malachite formations of Enssia, already described. In a great basin, formed in an amphi-theatre of bills is an immense dejtosit of clay, resulting from the decomposition of the clay slate of which the surrounding bills are formed. In this clay the remarkable deposit of copper ore ie found. There are some evidences which appear to show that the earliest condition of the mass was that of onde and native copper ; this, from the oontinned action of carbonic acid, contained m all probability in the water, was converted into a carbonate. There are no appearances of any mineral lode of the character which occara in our own copper mines. The veins, said to be met with, aro merely extensions of the mass by infiltration through the olay-

103 The Phincipal Flogsu

the shipping port, and the diaad vantage of niunade roads, these re- mBrkable mines nor erthetess yielded during the first five years a proQt of nearly half a million sterling ; certainly one of the most BQCccasfvil mining ndventnrea upon record. When, in 1851, the gold fever HDt in, these important mines were deserted by the working miaers ; but when men had begun to disoovor that the profits wMoE are obtained from the esoiting bat uncertain search for gold are nob commensurate irtth the risks run and the labour espoaded, they retnmed to more atttble sources of employment, and in the early part of 1665 the workings at Burra Burra were resumed, For severa,! yeaxs little was heard of the mine, and its fame was eclipsed by the fine discoveries in Yorke peninaulu; but reoontly the mines have ftgain been brought into active operation.

In Case 36 (p. 69), on the western side of this floor, are Bome fine specimens of the red osido and blue and green caibonates from tha samemincB; and ia the lower hall is another large mass of the ore (!No. 34). There will also be found in the hall a 6ne sample of the ore (No, 174) from the workings of the Gtroat Northern Mining Company of South Anstralia, commenced in June 1860, in the district north of Port Augnata, at the head of Spencer'a Golf 48).

Oaae 38. — The Sonth Ansti'ftlinn copper ores are continued in the upper part of this case. Samples of copper glance and other rKh ores are exhibited Irom the Kaponda mines, which have been sno- cesafnlly worked since 1844, and were indeed the first workings in the colony. Other apecimeni bayo been contributed by the mines of Mount Barker, Eeedy Creek, Kanmantoo, and New Cornwall, the laat-nained being situated in the neighbourhood of the bi'illiamtly- Bnceeasful workings at Wallaroo, on Yorke peninsula.

The discover of copper-ore ia this district was made by a shepherd in 1860, and the Wallaroo mines were at once started. Another discovery was soon afterwards mode about 10 miles sonth of Walliu'oo, which resulted in the formation of the valuable Moonta mines.

Passing over the lead, iron, and antimony ores, which are at present only of inferior importance to the colony, wo meet with a number of samples of tin ore.

The Australian llack sand, as it was commonly called, did not for some timo uttnict attention, except for the gold which it contained. Eventually, however, it was fonndTtO contain tin ; some Bamples were sent to England and determined to be of conaidcrablo value. The quantity of tin produced in Victoria, np to the eud of 1873, baa amounted to upwards of ijOOO tons.

Vast discoveries of tia-stone have recently been made in New South Wales and in ;Qneenaland, where not only do valaable lodes occur in granitic rocks, -but siream-tin is found abundantly in the beds of many of the rivers and Jn alluvial flats. Tin-ors has also been recently discovered at Mount Bischott' in Tasmania. The new- Australian and Tasroaniwi deposits are ftiiriy represented in the case before ua. In 1874 we imported 5,800 tons of tin from the Auatralian,

The few specimens of Anstralian cool will be regarded vrith much interest, for tho carboniferons formations of Australia have yet to be developed. Important deposits are, however, worked in New South Wales .tmd in Queenslid.

New Zeaiand.

Case 37.— Of the few minerals exhibiteil from the Northern Island,

parhftpa the most interesting is the fine Kiai/notia i'i-on sand, which

ixoaram deposits of vast extent along the atoto o!"S \>\-am.wj.tV,

Colonial Products. 103

at tlie base of tlie trachytio cone of Mount Egmont, in Taranaki. Tbe excellent quality of the steel prepared from this sand is supposed to be referable to the large proportion of titanium present, an analysis of the ore yielding 88*45 per cent, of oxide of iron and 11'43 of oxide of titanium.

The samples of auriferous quartz sufficiently show the character of the gold ore yielded by the famous Thames gold fields, neai* Auck- land.

There will also be found in this case a specimen of copper ore from the lower palaeozoic rocks of Kawau, near Auckland; and some samples of New Zealand tertiary coal obtained from Waikato, distant from Auckland 35 miles, and 10 miles fromManukau harboui*. Coal is also obtained at Matakana, 15 miles north of Auckland.

East Indies.

Case 37. — An interesting and extensive series illustrating the varieties of corundum stands at the head of the Indian minerals. The name corundum is applied to the opaque, roughly crystallized varieties of native alumina, whilst the massive and more impure forms of the same species are known as eniery ; the passage of co- rundum into emery is illustrated in this series. From its hardness, which is inferior only to that of the diamond, the mineral in its coarser forms is extensively used for grinding and polishing pur- poses (p. 42). As these varieties of alumina will again be brought under notice in describing the contents of the horse-shoe case, we may pass, without further remarks, from this series to the iron ores of India, which will naturally attract much attention. The lower part of this case is devoted to metallurgical illustrations, but the ores from which the metal is reduced are principally shown in the fol- lowing case.

Case 38. — The celebrated "wootz,*' or Iiiddan eteel, is manufactured by the natives, chiefly from the magnetic ores, of which many sam- ples ore hero exhibited. The method employed for smelting this ore is very rude. Layers of small pieces are disposed alternately with others of charcoal in an open furnace, and exposed to the blast of two small bellows made of goat-skins. The metal when reduced falls into a hole at the bottom of the furnace in the state of malle- able iron. To convert this into wootz steel, a small wedge is cut from the iron cake, and placed with pieces of dry wood in a clay crucible, which is heated in a rude furnace until the iron becomes carbonized, and on breaking open the crucible the steel is found at the bottom in the form of the small conical cakes here exhibited.

The iron manufacture has been carried on somewhat extensively in the Damoodah valley and Beerbhoom. At Dyoucha," says Pifofessor Oldham, there are at present about 30 furnaces at work for the reduction of the ore into pig iron, or what is here called cutcha iron, and about as many more for refining it, or making it 'pucha ; the two operations being carried on by totally difierent sets of people, and, what is curious, by people of (ufierent religions, those who re- duce the ore in the first instance being invariably Mussulmans, and the refiners as invariably Hindoos.

" From each of these furnaces when at work between 20 and 25 maunds of pig iron will be turned out during a week. The furnaces work throughout the year, with only occasional stoppages for poo- jahs ; that is, provided the proprietor has been able to lay in a. stock,

104 THE PSINGViBi VUWBL 1

From each fviniaee, therefore, a ptodnee of pig iron of about 1,100 jnaande, or Hourly 35 tone, is annually obtained."

At Dyoucha are 30 fomacea, at Narainpore about the same num- ber, at Damrah four, and at Goanpore six, or in all about 70 furnaces, producing nearly 2,380 tons of pig iron every year. lu refining nearly one fourth of ita weigLt ia lost, 10 mav/nda of the endcliti iron yielding about 7 vuiwids 10 of the vaelia iron. This will give the entire produce of the wbole diatrict at aboat 1,700 tons of refined iroa.—Oidliain'B liemrt on the DaiJioodali, VaUay,

A few Baraplea of copper aud antimony ores are introduced. It ia knowTi that the Himalayan moujitaina contain copper and lead, bat the mines have only been worked superficially, and it ia doubtful whether they would repay the great coat which must be inonrred. In aeveral other districta, Ulwar and Beerbhoom, Bellary, Dhun- niara, TennasBerini, and Nepal, copper ores are found.

A rather extenaive series of useful non-metallic minerals ia ex- hibited from the Madras Presidency. 'Hess embrace several varieties of haolin or china-clay, valuable in pottery mannfacture {p. 141) ; and a collection of variously -coloured ochres, which, both in a native and a bornt state, are aruilable us pigments.

Case 40. — The noa-metallio minerals of India ore continued in this case, the upper shelvoa being occupied by some fine specimena zeolitic mineralH from the tunnels cat through the trap-rocks of the Shore Ghaut during the couHtruction of the great inclme which aacenda the Syadrahee range on the line between Bombay and Poonali.

Among the minerals on the following ahelf, the specimen of is notable as a representative of the vast deposits of this siliceous variety of carbonate of lime, which occurs in singular concretionary forms, and ia largely hurat in India for lime.

The specimens of tin ore from the Malayan peninsula, and from the isle of Banca to the south of it, are intereatiug from their com- mercial importance. From these, and other adjacent localities, tin has long been obtained, and Humboldt waa of opinion that the Phcenicians, by means of thoir factories in the Peraian Gulf, main- tained a Lrade in tin with India ; and ca the word Kaseitaroe ia the ancient Sanscrit word Kastira, he is dtspoaed to regard the islands of the Eastern Archipelago as one set of islauda, to which the term Cassilericka, or " land of tin," was applied.

Tin from onr other eastern possessions comes to us through Singapore; but this ia mixed up with much which is produced m the Dutch Eaat Indian possessionB. In 1874 we received from the Straits Settlements 4,177 tons of tin.

Bkitish Amewca.

40, — Tho mineral wealth of Canada, with which the labours of the Geological Survey have made us acquainted, ia very fairly represented through tho courtesy of the late Sir William Logan. Aftbough some of the apociraena, on ncconnt of their size, are necea- sarily placed in tbe following cases, it will be convenient to describe in this place the whole of the Canadian aeries.

As especially interesting among the non-metalhc minerals may be noticed the apalile or phosphate of lime, which ooonra in con- siderable deposts iiL the Laurentian limestones, and is highly valued by the agriculturist as a ueeful fertilizer (p. 48). The platen of Canadian micd, which are found of estraordinaiy siao and thicknesa, have been employed in certain aitnationa as a substitute for the more

COLOiriAL PRODUCTS. 105

oaeilj injnreii gloaa (p. 68) ; and tho ffra.hite, or hlack-lcad, has nlso been -worked, alChoagh occurring only m irrnlar deposits of :io very considerable eitent (p. 123).

Whilst the ItmesUmes are notable for furnishing these minerals, the grnnitia and gneiasoBe rocka deserve mention for the fine apeci- raona of felspar which tfaey yield. The peonliar sodo-felsjiur trailed peristorite ia remarkable for its beautiful blniah opalescence, whilst the variety of potash -felspar knovrn as pcrtiiite is attractive by ita peculiar banded atructure and aventnrine-like reflections. Set poliebed specimen in Horae-ahoe case (p. 132).

A Eample of ooralline limestone fraai Enniskillen is interesting the rock from which probably arises the Canadian j>eiritUttm, or rook-oil ; the wells in this localihr lieing carried throagh a con- siderable thickness of palteoeoic shales overlying this comiferoas limestone.

Passing to the metallic mineral*, we may notice from the Brnce uiines, on the shares of Lake Horon, the nne earaploa of the copper ore, which oocnrs in rich veins traveraing thp Hnroniaai rocka, or those which immediately overlie the Laurention series. Considerable interest attaches to the Canadian iron ores, the bog ore having a very wide superficial distribution, and the richer magnetic ore occoiring in beds of prodigious extit. The titaniferoud iron, from its occurrence in large quantity, promises to bccomo of considerable importance, whilst certain varieties of iforc pyrites appear to contain an amoant of cobalt sufficient to render profitable the extraotion of this some- what rare metaL From Eastern Canada are obtained the chrome iron ores, which, aa uanal, are associated with serpentine rocks. For further information on this series tho visitor ahonld consult the "Reports of Die Geolog'wd Sv/rcey of Oana:la,"

Before leaving Case 40 attention ahould be drawn to the specimens of gold, and models of nuggets, from the Gilbert Eiver in Lower Canada.

Case 41.The specimens in this case which will doubtless be regarded with moat interest are those illustrating the gold disco- veries which havo been made in British America during the last twenty years. From Nova Scotia are exhibited samplee of the ao- called "bairel-qnortz" of Laidlaw. Occurring beneath only a few feet of quartzose rock, it forme an estensive horizontal bed, pre- senting a remarkable succession of folds or contortions ; probably the result of lateral compression. The undulating surface of the deposit, which has suggested the local name, is well seen in the water-colour sketch in the upper part of the case, where the barrel- quartz ia exposed by removal of the superficial rock,

A prominent position in the case iiefore na ia neceaaarOy given to the collection illustrating the extensive gold districts of British. Colnmbia. It appears that aa early as 1852 small quantities of gold were found in Queen Charlotte Island, and the metal was afterwards discovered on the mainland, in the Frazer Eiver 'yaUey, and in various parts of the Cascade range. The firat official report of these diacovenes, which was received in 1856 from tho Governor of Van- convBT Islsjid, failed to excite any considerable attention ; but the extent of the deposits and the aucceBS of the operations which were in progreas being confirmed by aubsequoiifc reports, public attention, waa at length aronaed, and in 1868 vast numbers of emigrants flocked to the new colony.

The great centre of tho moat succeasful workings waa the rich auriferous district situated some distance inland, and known (from being a favour'ite haunt of the reindeer or earibcuaf) as the Cariboo

106 THE rsmctPAii m-ooe. '

coBntry. The beda of the Fraaer Eiver and ita numerouH tribotariea were aleo highly produotiTe, aad the aUiivial teiraoea which bordM inipj of the etJcaiaB yieldod much gold to the "benoh diggers." Mare to the eouth, oii the eastern aide of the Caeoade range, gold has been worked ia the Similkameen, the Okanagan, aad other streamH which ore direct or indirect tributariea to the Colombia

After a pericd of auccessfiil operations, in some cases of the most brillinnt chftmcter, the workings gradually becaiae less productive, and were far the most part abandcmeJ; the washings at present being carried on only to a very limited extent, principally by Ohinamcn.

The Wat Indies arc represented by a small number of apscimejia, chiefly from Jamaica. The eiisteBce of copper ores and other minei-alfl in this island have long been known, but the esplorationa which have hitherto been made have not been snlScientiy extensive to decide whether the metoUiferoua mineral exists in sufficient qnantitiea to warrant a large outlay of capibal.

South Africa.

Case 42. — If the copper ores just noticed are only of meagre interest, it is far otherwise with those in the collection before na. The copper ores of Namaqualand, which merit considerable atten- tion, are very fftii represented by a tolerably anmerous series, con- tributed by Mr. Wyley. The ores occur in veins traverBing highly contorted gT'anitic and gneiasose rocks, and presenting a considerable variety oi copper-bearing minerals. In the upper parfc of the deposits, where surface-action has been moat active, the copper ore ia ohiefly in tho form of silicate and oxide, but theae are commonly followed at a greater depth by purple ore, nnd this again by copper pyrites. Considerable quantities of iron ore occur with theae copper minerals, and a little molybdenite is occasionally present,

The diamond iields of South AJrica are illustrated byspecimeaa in the central horae-ahoc case (p. 122). Among tha non-metallic mine- I'&ls in the case before ns there are several specimens of the brown flbroos quartz which under the name of cat's-tye has lately been polished and largely used for purpoaes of ornament. - In the upper part of the case are some Indian spears from South Africa, m.a<ie from the native carbonate of iron, reduced by cow

Having completed onr survey of the Colonial products, we return to the British ores which remain to be noticed. These are the lead ajid iron minerals which occupy the succeeding oaeea.

BRITISH OEES. 2ud Division.

Lead.

Cases 43, 44, 45. — Lead mining has been can'ied on in thi country from a very early period. When in the posBeaaion of the Eomans, many of the leaa mines in Wales and England were worked, and oonaiderable quantities of lead obtained, as we may infer from tha immense aooumulation of slaga in Derbyshire, the Mendip hills.

' -fiRmSfi ORES. 107

and elsewliere. There does not appear to hUTO been any period in OTir history dnring which minin g For lead was not followed lo some estent ; bnt in the reigna of Henry Till, and of Qnoeu Elianbeth, especially in the latter reign, a fresh impetna was giTen to British mining by the introdnction of a nnmbor of German minerB. That mining for lead maet, preyionBly to thia, have been exteosivelj carried oat ia proyed by tiie circnmstaQoe that Edward the Black. Prince took several hundreds of the Derbyshire minora into Devon- ahire, and it ie eaid that the reenlt of his mining epecnlationa in the west waa the realization of wealth sufficient to defray the ex- penses of hia French wars. Many cnriouB laws were msulo for, and Bpocial privileB were granted to, particular mining diatricts, as the King's Field m DorbyBhire, and the Myne-deeps — a.s tho Mondips were formerly called. The workings fov lead io Cardiganshire by Sir Hugh Myddelton are noticed at p.

The Bishof Lead. — Among the curious customs of Derbyshire in the King's Field was this ; — The ore was obUged to bo meaanred in the presence of the bonaaster before it waa removed from the mine, for which purpose, in Wiiksworth wapentake, a rectaugnlar box waa used, 28 Laohes long, 6 wide, and i deep, and reputed to hold 14 Winchester pints when level full. In measuring tho oro every 25th dish is set aiiide by the barmoater as the Eing's cope or lot. An old dish of thia kind stands on tho model of tho stcol-works !No. 31, at the northern end of the room, and bears the following engraved insci'iptiou : t![f)ie Miefje tonf inaVc tf iitj tran o( Ottobrr tfie tiff gear of Itrfffnc n( teijiifl; Ifjc biii. befaie ficarQC iSrU at Tolbtiiavy ictUiiFli al lij;ng;£ maiit IjanerfthU l)ouficI|Dl]], iinis aliia gictuavO dC aft [jmimic of , bg t!)e Adrnt aiiU (ICaiidciit nSiucle of all tbe fiHgnauxa ai of all

etc Xrcniitrd tlKitbiit aiitt tounsiiQ Ifgc lartadljjiji o( eitt"''fi°i ))CrECll at t()C diiiQ fUomitir. VLiM Qijc ta IJcmamii in H)E aote oll Kt Wigtis\i>artt} aiisyiie ij! a CjEBnE S>o aS JHctcljaHUg ov iiicuQurd inniiabe rrSarte In ie Same at all temr S la malu: iftc true mcdur aft ftc Same.

It appears now usual for the Derbyahire smeltera to consider 68 lbs. as the standard weight of a 14 pints dish of ore.

The principal lead-producing counties of England are Durham, Jfortiumberland, Cumberland, Yorkshire, Derbyshire, Shropshire, Devonshire, and Cornwall ; in Wales, Cardiganshire, Flintshire, Montgomeryshire, and Denbighshire. Lead ia also obtained from four different oountiea in Scotland, from eight in Ireland, and it is raised in large (quantities in the lale of Man.. Orea from nearly all those diatricts will be found in these cases.

The TOQBt important ore of lead is the widely diffused aalphido called Galena. In addition to the lead, of which the purer varieties of galena contain upwards of 86 per cent., various other metals are UBually present in greater or less (quantity. Of these, silver is the most important, and it ia indeed highly probable that neither silver nor gold is ever entirely absent from galena. Tlie former is exten- sively extracted by a process which will be Bnbaeqncntly described (p. 116).

Following tho specimens of galena are samples of other lead ores, less widely diffused than the sulphide, but many of thetn, neverthe- less, of considerable importance. Foremoat among these stands the carbonate of lead, called Oerussife or while lead ore. This laiiiKwJw

108 TffE "tfttSotfiii 'OOfi.

BOiaetiiaeB occurs in acioulor or needle-shaped ciatak, of which et magnificent Bpooimen from DovonBhire will be found in the central caee So. 'H ; but more frequently it is found in an earthy form often investing galena, from whose decomposition it resulta. Among tha oxidized lead ores will also be found some brilliaut rhombic crjtals of An/jleaite or sulphate of lead, aud of the fine bine mineral called LinarUe, a Bulphate of lead coloured by copper. The phosphate of lead termed Pijromorphile, aad known to our miners as " greeu Jinnets," is a mineral in which the phosphoric acid is frequently replaced to a greater or less extent by arsenie acid, thus passiiLg into the species called MhnetUn. In these mineralB the phosphate and arsentate of lead are associated with plumbic chloride.

The rare raaadate of lead already noticed aa Vanadinile ie related by form and oompositiou to the phosphates and arseniatea oi* lead, tmd these again to the phoaphate of lime called apatite.

Ibon.

Case 46, — Jrora pijriiei, although containing nearly one half ita weight of metal, is used not so much as a source of iron aa of snlphur, and is hence commonly known as ' ' iJilphiu/r ore." In Oom- wall, where it is by no means an nncommon constituent of copper reius, it passes under the name pf " inv/ndie," whilst the coal miner, who constantly meets with impure varietieSj recognises them as " hraeus."

The name pijriies is derived from the Greek 'apWjis (purltes), because, aa Pliny says, " there loaa muckfira i/i it." Heaps of pyrites undergoing decomposition by the action of the atmosphere developo a large quantity of heat, in some instauces sufficient to set the mas

Iron pyrites ia easentially a bisulphide of iron, and is therefore identical in chemical composition with Marcasite, a mineral which, however, citaUizes in totally distinct forms ; ordinary pyrites appearing m cubes, octahedrons, or certain homihedral forms derived indirectly from the cube, whilst marcasite occutb in a series of prismatic forma, which have suggested the name of rho-miiie yntee. It frequently appears in irregulaily shaped nodules common ni the chalk, and the ciratals are often aggregated into groaps, forming the variety called " cockscomb pyrilee."

The arsenioal pyrit-es or Mispickel has already been noticed as a source of arsenic {p. 91), and the bronze-coloured magnetic pyrites or Fyrrhotitie has been mentLonod in the description of the foreign

Vivianiie, ehildrenile, and pharMacosiilerite are minerals which will be fonnd in this caae, but all being of rare occnrrenco they merit no special description.

Caae 47. — The value of Magnetic iron ore ia Sweden, Eussia, India, Ac, for the production of a veiy superior quality of steel has already been noticed. In this country, however, the ore is comparatively un- important, occurring only in very limited cjuantity. The peculiar pisolitic ore from Boaedale in Yorkshire is interesting from ita occurrence in the lias as a deposit of considerable extent.

Case 48. — As the moat important of the numerous localities ia which the valuable Siemoiife or red iron ore is found in this country, maybe mentioned TTlverstonB in North Lancaahire, and Whitehaven in West Oamberland. The ore is highly prized for yielding a pig- iron well fitted for conversion into Bessemer ateel. The crystaUizod rarieliy called speeuiar we or trow rfiaTice ia lei-eaented by some 'J>ocimezi3 from tha Cleator Moor depoaibs.'wtOTQ itoc(i\irftVQ.<ia.V\6i

r BSmSH ORES. 109

in the compciot ore. The delicate Bcaly or lamellar crystiils fVom Devon and Anglesey ahow the charactera of the folinted variety of epecular iron called micaceous iron are; whilst the fine renirorm and mammilla ted samples of compact htematite from CnmberUnd and Lancashire exhibit well the characteristic fornts which hare sngeeated for theae vwietieH the popnlnr designation of "Mtlniy or/r." Ou acconnt of the red colonr of the powder the came hamatite, from JfM {haima) hhod, is applied to this species.

Case 49. — A mineral eo ahundant and so widely diUbsed as Iiimonile or bi'own iron ore natmlly roqoires nn extensive series for its illustration. Among the nnmeroriB localities reprcsentd in the case before ns, tlie Forest of Dean may be cited aa a district in which the brown ores have long been raised. The botryoidal and etalactitic forma, sometimes called - [rrmcii kisraatitei the fibroaa Tivrietiee, termed from their atructnre wood inm ore; and the friable earthy forms known as yellow and brown ochret, are bo many Tarieties of this one specicH. The composition of these varieties is enbject to variation within certain limits ; but a orystalliEed hydrona peroxide of iron of definite composition is occasionally met with, and nas been separated ae a distinct species under the name of (lolhile. The maifioent specimens of gothito from Restormel, near Lost- "withiel, m Cornwall, are in every way worthy of notice.

Tho brown iron ores of the secondary stata, especially those oF the liaa and the overlying oolites, have ncqnired considerable impor- tance within the last few years. Samples of these will be founa in the lower part of this case. The celebrated Cleveland iroM<yn was diaoovered in 1848-9, on the north-eastern coast of Yorkshire. " Prom Eedcar to Middlesbro'-on-Tees there crops out a solid stra- tum of no less than 15 feet thick, Thia remarkable ironstone aeam extends over a region of some hundreds of square miles. It is capped by aandy shales, containnig scattered nodules of ironatoDC, and ultimately, above the vkwIsIoiie esriea to which it belongs, by the upper liaa ahoLe, so well known along the Whitby ooaat for its fossils, jet, and the amplication of some of tho beds to the mann- facturo of alum." — (W. W. Smylh.) The main body of tho Clere- land ore is a carbonate of the protoxide of iron, but the upper part of the deposit passes into brown ore.

In NorthamptonBhire and LincolnahirB, ironatones are now exten- sively worked and smelted. The Nortkamplonehire vronsUyrm occurs at the baae of the Inferior Oolite; while the Liiteolfuhire iromtone ia fotrad partly in the Lower Liaa and partly in tho Neocomian series. A liaa ironstone is also worked at Fawler in Oxfordshire, and an oolitic ore (coral rag) at Woatbary in Wiltshire (p. 60), whilst BuckinghamsMreyields iron-ore in tne Lower Grreensand.

Case 60, &c,— 1*116 characters of the pure carlaonato of iron have been noticed in the description of the foreign orea (p. 91j. In tho eaae before us, in addition to tho j'hombohedra! ujid lontienlar cryatala from Cornwall, are specimens of snathoae ore from the Tamable deposits of the Brendon Hills in Someraetshire, and of Weardale in Durham (p. 60).

Bpathose iron ore is a mineral whose composition is subject to conaiderable variation, the carbonates of lime, magnesia, and pro- toxide of manganese frequently replacing to a greater or lesa extent the carbonate of iron. Moreover this carbonate of iron is frequently associated with impurities which interfere with its cryatalmation, and give rise to the dark-coloured massive varieties called clay-iron~ jfonsB. These impure carbonatea-which. o.tb ho -tqIos trihated throngbont onr coal-measures, paarft? wi leKoNav ssraM variable tlucinese, and partly a& noinW owaci;U'— t'aisaWOie.

the ore which, in this couutry, yielded trntil recently by far the largest amount of our iron — a fact by itself a, anfGaient apology &jr the rather hige amoimt of space devoted to the display of these ores, confoBBedly Homenhat unatliactivo in appearance. Bnt the eihihj- tion of a complete serioB is the more desirable in an institution of a practical eharacter, aiuoe the ores, poaaeaaing neither cryBtsJline foim nor definite chemical ooia position, are not entitled to toko rank as trne minoralogjcal epecies, and wonld therefore find no place ia a purely sientific collection.

The extensive series of cloy ironstones commencea with a nnm- ber of specimens illustrating the characters of the nodnlar forms, and the minerals which these nodules frequently conttuii. The lower part of the present esse and the whole of the aii following cases are occupied by the systematic coUeotion of ironstones, arranged geographically in the following order: — South Wales, North Wales, Shropshire, South Staffordshire, Wamicksldre, North Stafl'ordabire, Torlahire, Derbyshire, and the Northern Oonnties.

Intercalated with these argillaceous carbonatea of iron are a few eamploB of the carbonaceans ii'Dnatone, well known as blaeh band. Fi'om this ore, which was discovered in 1801 by Mr. Mnshet,' and ifi hence frequently called Maiiel eloae, the largest quantity of the Scotch iron has been for many years made.

Information on the aeries of ironstones wUl be found in the "Mineral Catalogae," and further details in the Memoirs of the Geological Survey on the " Iron Orea of Great Britain ;" whilat the best idea of the value of our iron mannfactore will be gained by conenltiug the " Mineral Statistics."

THE METALLUBGICAL COLLECTIONS. In tho reoeaaes on each side of the room at the southern or Jermyn. Street end tho -visitor will find six flat cases which are devoted exclnaively to the illustration of metallurgical operations. These cases are placed, as for as convenient, in front of tho waJl-caaaB containing tho correaponding ores whose metoUnrgical treatment is here illustrated ; the series of iron-smelting products, for eiample, being arranged immediately in front of the British iron orea. The

g-ocessas illustrated in these cases, although for tho most part ritiab, are by no moans esclosivelj ao; specimens from foreign works being, in many inatancea, placed by the aide of our own pro- ductions for purposes of compariaon and illustration.

Metallurgical operations, preaenting, aa they frMuently do, oon- Biderable complerity in their details, could not posaibly be described in a popular goide with anything lite scientific precision ; but in order that the collection may not be entirely barren of interest ta' the general visitor, it seems desirable to introduce a brief sietch of the main featurea of each process, referring for detailed informatioii. to any modem work on the subject, espociaUy to Dr. Perey's " Metallurgy," or to FUUips' " Eleiiieats of MeMlwgy."

CoppBK Smeltks. Tohle-eae 47. — The ore when raised from the mine may bo more or leas pure ; it may be mixed with other metaUio minerals or with earthy ones, and it baa therefore, as a first operation, to be fi-eed as much as possible from those. The proceasea employed are termed "dreiainq " OS the ores Bold in GomwdJl m \8T4, tta higheat per- ceni /or cojjper waa 20i, the YoweatbemaV TbiaAiaja's.wft\

METALIiUKGICAL COLLECTIONS. Ill

nnderBtood as tne copper contained in select specimens, but as the per-centage of the mass of ore sold. In the boxes in this case are shown the ores in their various stages of preparation nntil they pass into the hands of the smelter.

Copper smelting, which is conducted in this country almost ex- clusively at Swansea, in South Wales, involves a somewhat elaborate series of operations, of which a very bare outline must suffice. The dressed ore having been calcined in a reverberatory furnace is fused to the condition of coarse metal which, after calculation, is molted with certain oxidized copper ores, and the wltite inetal resulting from this fusion yields, on roasting, a crude variety of copper, wMch is subsequently refined by exposure to oxidizing influences in a rever- beratory furnace. During these operations the sulphide of iron in the ore is converted into an oxide, which, combining with the siliceous matters present, forms a fusible slag; and the iron being thus removed, tne sulphide of copper suffers decomposition, its sulphur being evolved as sulphurous acid, whilst the oxide of copper, formed during refining, is reduced in the final operation of toughening. In this process the surface of the metal is well covered with anthracite, and a joh, usually of green birch, is held in the liquid metal, the evolution of gaseous matter causing considerable ebullition. This operation oijpoling is continued until, by the assays which the refiner from time to time takes, the metal is shown to be in the best condition. This operation requires great care ; both under poling and over joling being found injurious.

The various stages in the Welsh process of copper smelting are illustrated by a fine series of specimens presented by Mr. Vivian.

Copper passes into the market in the conditions of cahe (ingot) and sheet copper of various descriptions. That used for making brass is granulated, that its surface may be increased, so as to com- bine more readily with zinc or calamine. The granulation is effected by pouring the metal in a molten state into a vessel pierced full of holes, supported over a cistern of water. When it falls into hot water the copper assumes a rounded form, and is called hean slioi, and when into cold water, from its assuming a ragged appearance it is called feathered shot. Copper is also cast, chiefly for exporta- tion to the East Indies, in pieces of the length of six inches, and weighing about eight ounces each these are called Ja]pam, copper. By the side of these will be found an ingot of real Japan copper brought from Shanghai. (See also Case 44, p. 75.)

Some specimens in this case illustrate Mr. Weston's process of refining copper by addition of "phosphorus-copper," or a compound of copper and phosphorus. The process has been carried out at the Chatham Dockyard.

Table-case 48. — In this case are exhibited some interesting speci- mens illustrating certain Continental pj'ocesses of copper smelting.

The treatment of the remarkable Kupferschnsfer or copper-slate (p. 89) is here illustrated. This schist, which is extensively smelted in the neighbourhood of Mansfeld, contains on an average not more than three or four per cent, of copper, with a small pro- portion of silver. After calcination for a considerable time in large heaps, the ore is mixed with a certain amount of slag and flux in the form of fluor-spar, and the mixture fused in a cupola furnace ; the product being subjected to successive roastings, until at length a concentrated regulus is obtained from which the silver is ex- tracted, and the copper-bearing residuum subsequently smelted. At the time this series was obtained the silver ©sbt-w

nreseut ft somewhat difTereDt jirocesB is adopted. The (!i-ndc copper u refined in a reverberatory furnace, the refined nietal being ran out into two external baeine, where ft little water is thrown on its Burfaoo, in order to determine the sahdifioation of the anperfioinl cmat, which is removed in the form of a thin circular plate or roeeltt ; more water is now thrown on the fused maea, and other dince are aucceseivelj obtained, until the whole of tlie charge him been removed. By the eide of these German specimens ia a email ((roup illeatrating the process of copper emelting at Falon in Daiecariift. pad in the lower part of wall-caae 17 will be found a fine sample of the celebrated, but by no means rich, ore of lliis district,

SjcELTiiie.

Tahte-te 48. — In this oaae will be found an old block of tin ob- tained from the tin dietrict of St. Agnee, and in the adjacent Wall- case, No. 10, are some other ancient blocks of Cornish tin, blocica are called Jews' iln, and the rude fumacBB, which are not nni'reqoently discovered in connesion with them, are known, as Jetc' houeee. This ariees from the fact that during the roign of John, and HubBequently, the tin. mines of Cornwall were farmed by the Jews. Those blocks, and the fnmaces named, are, however, nro- hably much older than this; they possibly belonged to the times mien the Phcenician merchants traded with Britain for metala. A model of a remarkable block of tin, which was fished up from off" St. Uawee, at the mouth of Falmouth harbour, will also he found in Case 10. The original block ia in the Mueemn of the Royal Institution of Cornwall, at Truro. Sir Henry James has shown, with much in- genuity, that the form of this block peculiarly adapted for ita transport, both by land and water.

Tin smelting is a aimple operation, conducted either in the rover- beratory furnace or in the blast furnace. The houses in which the first plan ia adopted are called avielling koueee; thoao in which the latter procesa ia employed, hhuiim houeee. The tin ore, having been roasted and washed, ia raised with powdered anthracite; and a amall (juontity of either slaked lime or fliior-spar, which serves as a flux for its siliceous impurities, is mixed with it previouslyto its being placed in the furnace and smelted.

During more thim sii centuries the tin paid a tax to the Earla and Dukea of Cornwall. The blocks of tin were Bubjectod to a process called " coining." and certain towns were fixed upon as coinage tome. The blocks of tin— rectangular massos— weighing about 3-34 cwte, each, were aent to the coinaife Hall ,- a comer of each of the blodis was struck olF (see Coinage pieces in caae), and examined by Duchy officers appointed for the pmpoae, in order to see that the tin waa of proper quality; the blocks were then stamped wilh the Duchy seal, the dues paid, and the blocks permitted to bo sold. By an it of Parliament of August 16, 1838, the duties pable on the coinage of tin in Devon and Cornwall were abolished. The Stannary Courta of Cornwall are now aupported by a small tax npon all the ores raised in that county and in Devonshire.

The finer varieties of tin, known as grain tin, which arc used princi- pally by the dvera, are usually prepai*ed by heating blocks of that metal in a batn of melted tin, which, at a certain temperature, are broken by a blow from a heavy hamjner. .

Oxland's proeesa for tepamtintf u-ol/ram (a doubt tungatate of iron and manyaneKe) /rmn. (in. — This process was first introduced at Drake

METALLUBGICAl. COVLECnOTSS. 113

"Walla tin-mine near Tuvistook. It consisN in mixing witli a little carbonate of Boda, tin iphlit, — that is, the dressed tin from the Htampa floors, ready for the bnmiag honse. appenr to siKiiify iMleg, indicating the white metallic look of the washed ore, mim the preBence of iron and of arsenical pyrites. The tin from the bnming house is sorted into jigged fiwan. that is, very Bmallniniw, snialts — slime and roms, i.e. rongha. The mixture 13 then heated to redness in a reverberatory furnace, when tangstate of aoda is formed, and the oxides of iron and manganese are liberated. The tungstate of aoda, which is a soluble salt, is readily removed by water, and the oxides of iron and mangBDeae aro separated trom the lixiTiatod tin by washing. The tnngstate of soda la now collected and employed, amongst other things, for rendering testila fabrics non-inflummable. The tungstic acid in a state of purity has been used in the mannfac- tnre of stoel. (See Table-case 51.)

Aivilent SroH Weapons, .S*c.— A few examples of these are placed with the tin for the purpose of showing that at a tcit early period the nse of that metal as a subitance capable of hardening copper, and producing therewith that useful compound metal, hiimrte, was known.

The art of casting bronze is traceable to the remotest antiquity, nnd nearly all the bronze celts, Hpeors, arrow heads, and sworda, to- gether with bronze statues and coins which have been discovered, have a similar composition, and that the best, for producing the required degree of hardness. Ancient bronze weapons have usually been found to oontam from 85 to 90 ports of copper in 100 parts, the remainder being mostly tin.

AgBipan Bronze. — Mr, Layard brought from Assyria the bronzes in this case, which were constructed for the purposes of support of some kind. Dr. Percy fonnd that the bronze had been cast round a support of iron, by which means the appearance of cooBiderable lightness was attained, while great strength was enanred. This discovery proves that the metallurgists of Assyria employed iron for the purpose of impartinR strength to the less tenacious metala which they employed in their art manufactures. The bronze, ns Bnalysed in the Metallurgical Laboi-atory, consists of copper 88'37, tin 11-33.

2iHC Smeltinb.

TalU-case 49.— Aicola, and others in his age, regarded calamine as an earth containing no metal, although it had long been employed in the mannfactnrc of brass. Tan Swab in 1742, and Magrai" in 1746, separated zinc from calamine by distillation in close vcaseta. Pott, in 1741, wrote a dissertation on zinc, in which he speaks of it OB a eemi-metal. The name nine first occurs in Theophrastna Para- celsus. Agricola (Be Re Metalliea) calla it conirefeyn. Boyle names it eUTurii. It was also called epiaiitar and Indian tiri. There is every reason for believingthe story to be correct which refers our knowledge of the metallurgy of zinc to the Chinese. It is said that an Englishman took a voyage to Obina for the purpose of learning the art ; that be returned and established works at Bristol, where zinc was obtained by distillation per deseensam. Dr. T. Lawson appears iJo have been intimately connected with the early sine works in this country ; and to have associated himself with Mr. Champion, of Bristol, in the establishment for smelting calamine, about the year 1743.

The zinc ore, whether calamine or blende, is first-roaated, and

the oxide thus obtained reduced by smelting with. (iMnsnaajiKi'i*

40332. -a

1 1 -6 THE PHmCIPat, FLOOB.

matter. In tbis country tha rerlootion is effeotail in a cracible, prdyided &b the bottom with a tubo, through which the zinc vaponr descenda.

The oelebrated yieille Motitase ores have been noticed at p. 92. Tha AbbS Deny first eetahliahad the smeltina; worka, which aeied into tho handa of tho Maaselman family ia 1813, and in 1837 into the poBsesBion of the pfeeent proprietors, the VieiUe Moobagne Zinc Comnatiy. Tho distillation is coodacted in a series of olay retorta, fnruished with caat-irou conical condenaerH. A. model of the fiumaoo ia exhibited in the ffnllery of the Model Room A.

Zinc ia employed larfly in the mannfactare of braes, it ia alao used for covering sheet ii'oa fgnlvaMiaed iVoii) for baths, water tanta, and pipes ; plates for the engraver, and for zinoography, and e, variety of other pnrpoaos, including the mannfaoture of the pigment :(jrB while, or oside of zinc.

The extraction of sine ad prcpai'ation of the oxide as oondnoted by the Lehigh Zinc Company Bt Bethlehem, Pennsylvania, ie well illnatrated by a large suite of apeoimena presented by the company, and exhibited in the caao before na.

Bbass.

Tohle-txue 49. — In the arrangement of these table-cases we have first the pure metals, copper, tin, and ziac ; then copper and tin, foi'ming bronze ; and finally copper and zinc, forming brass. This alloy is well known, and requires but little esplanation.

For the production of differently coloured braasea, and to meet the rec[uii-ed conditions of various manufacturing proceaaea, the pro- poi-tions of copper and zinc in braea are infinitely vai'ied. A com- mon proportion ia 2 parte of copper to 1 of zinc. Formerly brass was manufactured by heating m cruciblea a mixture of granulated copper, calcined calamine (carbonate of zino), and ground coal. At the present day, however, the alloy ia prepared dii-eclly by fueing together the proper proportiona of copper trndBiuceitherinoruciblea or in a reverberatory foinoce.

Nickel ant Gekiuh Silver. Tahh-case 49. — The metallurgy of nickel ja UBuaHy kept' a secret by the mannfacturci's. Ip Case 14 will be found some specimens illustrating the erti'action of nickel in Sweden. The metal ia pro- duced in large quantities to meet the demands of the makers of German ailver. Shefileld German silver haa been found to contain 57 x)er cent, of copper, 24 per cent, of nickel, and 13 per cent, of

Several white metals bearing different names, sach as nickel silver, albata jilato, &c., ai-e only varieties of the Gennan silver. An ornamental casting in German silver, showing the character of the metal aa it comes from the mould, ia in Caae 43.

SlLiXTS iND OTHEB COEALT COLODKS.

Tabh-caee 49.— The preparation of the beantifnl cobaltblues was discovered in Saxony about 1540, and it haa since that time been carried on estenflively in that country. The cobalt in the ores is converted into oxide by roasting, and the oiide of cobalt thua pro- duced is vitrified with the addition of pure potash and silica. Smce cobalt ia nsusJJj associated with many other minerals, the procesaea 'onaected with the preparation of sma,lt.*i6 at a-lfeUiayi (WawAat, SiaaJtisa cobalt glaea; this ground to fine pv&fit kd.4 wiftoaj

' META1.LTT110ICAI, COLtECTIONS. 115

washed is applicable to all purpofles in which, a cheap nud durable bine is rer|uired as a paint, and for giving a blue tint to paper or linen. Pure smalt maj be used for painting and colouring gliUB ruid

forceJain, but for delicate purposes the axide of cobalt is (Tnploycd. or caloDTing earthenware the roasted ore, with tui addition uf powdered fiint, which is sent into the market wider the name of Zaffre or Safior (a coimption from eapphirel, is employed; vrben mixed with the proper proportion of jwtaah, the colour retjuired ia produced in the prooeHH of firing the ware. In this case will be bond all the colonra produced bj chemical treatment from this metaL The silicate of cobalt and potaeh forma tvuilt, and eolxiU or LiGkiir'shhie ; oiido of cobalt aad oside ai tana, Rinman's green ; phosphate of cobalt with alumina, Tlietiart blue; arBenite of cobalt, purple; and silicate of cobalt, pink.

PLiiTNEB's Gotn Procesf.

Tohh-cage 49. — Plattner'a method of gold extraction is, or at leut was, nsed at Beichensiiein, in Silesia, for the treatment of reatduea of aenical ores (lolinglte) containing abont II ounces of gold to tlio ton, and about 5 per cent, of arsenic. Some four hundredweight of these residues are treated with chlorine gas in glazed earthenware veBsels for five or six hours. The chloride of gold produced by this means ia then washed ont with water, an operation that requires from six to seren hours. The free chlorine in the mucous solution so obtained ia neutralized with ammonia, and the gold separated by Bulphuretted hydrogen gaa as sulphide, which is redaoed, by calci- nation, to metallic gold. The finely-divided metal ia afterwards united by cupellation with lead.

Somewhat similar ehlorination prooeases have been largely era- ployed for extraction of gold in California.

Aksenic.

Tahh-etKe 49. — The substances containing arsenic usually bold some sniphur in combination. The ores are pliused on the solo of a reTerberatory furnace, thronh which a current of air is allowed to ploy. The sulphur present is converted into sulphnrona acid pas, and carried away by the chimney, while the arsenitnis acid (white arsenic) prodnced is oondensed in chambers prepared to receive it. To obtain pure arsenious acid the first products thus directly obtained are subjected to a second sublimation in oast-iron tnbea provided with cast-iron receivers.

A considerable quantity of the arsenic (araenioua acid) produced in this coontry is exported to Euasia, and ia used, it is said, l-gely in preparing some of the finer skins and furs. But tho largest quantity of araenio ia employed in the manufacture of emerald

The preparation of many of the other less common metals, and their compounds, such aa antimony, bismuth, cadmium, aluminium, &c., receives illustration in the Pedeatal-eaae No. 46, immediately opposite to tho table-case under description. For notice of the con- tents of Case 46, see p. 75.

The remaining table-cases of the metallnrgical series stand in tho three embayments on the opposite side of the room, to which there-

the sUver from it were known at a verj cav\5 "ser*.- TttViV

116 TTHEmtlNCIPAL FLOOB. "

Job, which perhaps one ot the eai'liest of the written recordi which have descended to ns, clearly describes the metalltirgical and mining procosaes; (ind in Jeremioh we find", "tha hallows arebarned, the lead is conanmcd of the fire; the fonnder melteth in vain.

Reprobate silver shall men call them." This passage proves the knowledge of the prooessea of desilverizing lead by oxidation, BHcli as until of late yearfi we have commonly employed. Ancient writers infonn na that lead was found so plentifully, and so near the Burface of the gi'ound, that it was found neceaaary, in the earlier period of the Roman occupation, to make a law limitinjj tbe quantity to be taken each year. The traces of Boman leiul mines are very eitenaive, and the discovery of Roman piga of lead by no m.ean8 uncommon. Tbeao were uaually stamjied with the name of the emperor under whose reign the lead had been produced. One of these Roman piga of lead will bo found in the collection, and two casta from other pigs which have been discovered. The original pig was one of fifty found in an old amelting work diacovei-ed near Orihuela, Valencia, Spain (Wall-case 44).

The following are the inscriptions upon the Roman pigs of

C-IVL-PROTI'BRIT'LVT-EX-ABa-

M-PEO-SCIEIS-MT-MAia

IMP-VT-SP-"\TI-T-IN'-T-COS LVT Mr. Wiight conceives is an ahbreviation of hitam, washed, and the EX-ARG' bethinks is explained by the following paasage in Pliny, Nat. Hist. lib. xxsiv. — Plumbi nigri origo duples'est ; aut enim sua provenit vena, nee qnicqnanj aliud es se parit ; aut cum argento nascitnr, miatisque venia conflatur. In Fennant'g Tom- in Waku, (Lond. A.D. 1810, 8vo., vol. i. p. 79,) will be found an interesting description of similar Roman pigs of lead.

The fto argento doubtleas signiGes that from the lead bo vaarked the silver had been separated — that it was indeed refined or soft

With a view to show aa clearly as possible all the details of the processes by which lead is separated from ita ores, freed of silver, and passed into the market, there are exhibited the varions results of dresBing, and of the smelting processes — and then the manufactured lead, as sheet lead, shot, and Imd pijies.

Metallic lead is ohtained either by simply roasting the galena, or native anlphide, under proper conditions, or by roaatmg the ore, and then reducing the oxidised products by means of carbonaceous matters, or finally by removing the sulphur from galena by heating it with metallic iron. The operations of lead smelting may he con- ducted either in revei-beratory furnaces, in blast-furnaces, or in shalLow hearths.

The process of desilveridng lead was formei-ly effected by osidi/.ing the lead, the oxide being from time to time removed from the furnace, leaving the silver npon the bed of bone ashes preiiared to receive it. The oside of lead has then again to be reduced to metallic lead; this process vraa in every way costly, and unlesa the per-oentage of silver in the lead was large it was not separated.

A process is now employed which is known as Pattbison'a process,

the late Mr. Lee Pattinson having patented tbe method by

which tbe lead is refined.

This cbetnist discovered that lead coi\ao\v4fttel, ot cr3B\XVaA. B.i

i"gber tempcratuK than an alloy oE leaA ani -, coMw\Me.-ua.-s

Metaixurgical Cx)Llectioxs. 117

that, if be kept lead containing silver in a state of fusion at the lowest temperature at which the fluid state could be maintained, solid masses were gradually formed, which when removed were found to be pure lead. Thus a large portion of lead in a state of comparative purity is removed, and the fluid portion which remains at the last is exceedingly rich in silver. In the Model Booic B. will be found a drawing, and in A. a model of an arrangement of pots for carrying on the Pattinsoniau process. The lead ia treated in the manner described, the fluid portion becoming constantly more rich in silver ; and this is passed from one pot to the other until, at last, the lead contains so much silver that it is not economical to carry this process any further. This lead is subjected to the oxidizing process and the silver separated.

While the old process was in use in the north of England, if the lead contained less than six ounces of silver to the ton, it was not found profitable to separate it ; and in Wales, if it contained less than 12 ounces they did not refine the lead.

The cost of refinmglead, previously to Mr. Pattinson*s patent, was from 30s. to 60s. per ton. By Mr. Pattinson's process it is profitable to separate the silver when it does not contain more than three ounces to the ton. Beyond this more silver is now obtained from the lead than formerly ; Pattinsonized lead never contains more than seven pennyweights of silver to the ton, when the process is properly performed, while the old refined lead seldom contains less than an ounce per ton, and frequently much more.

An interesting series of specimens is exhibited to illustrate Mr. Baker's process of softening hard lead, patented in 1860.

White Lead, &c.

Table-case 50. — A small group of specimens illustrating one of the processes employed for the manufacture of this pigment is here introduced. Metallic lead, cast into the form of gratings, is exposed to the action of the vapour of vinegar in beds of fermenting tan. The basic acetate of lefld first formed is decomposed by the car- bonic acid present, and in this way is obtained a <jp.rbonate of lead, which when purified by washing and levigation is ready for use as a pigment. When white leid is roasted it sufiers decomposition, and the residuum, consisting of oxide of lead with a little carbonate, is employed under the name of orange had. LWiarae is obtained by oxidizing lead in a reverberatory furnace, and the product when further roasted forms the higher oxide known as red lead*

Amalgamation op Silveb Obes.

Tahle-case 50. — The process of the amalgamation of silver ores as formerly practised at HalsbrUcke, near Freiberg, is illustrated by examples of each stage of the process from the ore up to the formation of the amalgam of silver and mercury ; and models of the apparatus employed will be found in the gallery of the Model EooM A.

The process consists essentially in roasting the ore with salt (chloride, of sodium). As the ores are usually of a very complex character, some complicated reactions ensue ; the main result, how- ever, being the conversion of the sulphide of silver into chloride of silver. This is mixed with mercury and some fragments of wrought iron, and, being placed in revolving casks, the mass is plete.

The Pbincipal Fxooe,

le M. — Some mercurial ores from Idria in AaBtria,

from Hnngary, are here aasociated with tLe motttllic mei'dirj a: tliB Yemiilion prepared from it.

At Idria the aulpbide of morcuiT is worked in a formation chiefly compoaod of black limestone asBOciated with au argillaceous schist, witii which it is eo' intimately mixed as to appear to have been formed eontemporaneonaly wiih. it. These minoa wore diacOTeced in 1497. The workings are carried on by means of sniall galleries, as the rock is too pliable to jidmit of large excavations. The ore, which ifl principally bibiuninouB cinnabar associated with native mercury, is obtaLnca at a depth of 830 feet from the surface. On submitting the ore to 'distillation the sulpbur ia espellod, whilst the mercury ia volatilized and collected in a aeries of condensing chambers.

If mercury is rubbed with sulpbur in a mortar the black sulpbide, ElMop's -mineral, ia produced.. If this powder be heated to redneaa .it sublimes, and if a proper vessel be placod to receive tbo eablimed substance, a cake of a fine rod colonr is obtained, called cinnabar ; tMa being rodaced to powder foi-ms the vermilion, of commerce.

Ihok and Steel Masupactore. TcAU-casea 51 and 62. — In woll-mnrked diriaions in Case 52 the results of the processes of smelting the ores of ii'on are shown from the following iron works : —

Whileliiiiveti Iron Worlds - - - Cumberland.

Loi" Moor ditto - - - "1

Boiciiny ditto - - - - V Yurkshire.

Fat'uleji ditb, - - - - J

EuBsdrs Hall ditto - - - South Staffordshire.

Fli/motdk ditto - - - 1

DomlaiB ditto - - - - Glamorgansbire.

Maeateg ditto - - , - J

Monkh.nd ditto ... - Lanarkshire.

It is not intended to give in this Guide Book any detailed ncconnt of the metallurgy of iron. The ordinary processsa are, however, of the following order ; The " mhiB," that ia, the iron ore, ia Bttbjected to calcination. To effect this the ore may be piled iti long heaps over a stratum farmed of large lumps of coal. Fire is applied to the windward end, and after it has burned a certain distance tbe hei is prolonged with the aamo materials in an opposite direction. It ia ' now common, however, to effect the calcination of the ironstone not in the open air, but in properly conatmcted kilna. The calcined ore is duly passed to the blast furnace.

lu the Model Boom the construction of a hoist furuace can bo studied with its associated blownng machine. In the blast furnace tho proper mixture of iron ores and limestone is placed with a sufficient supply of fuel. The limestone (carbonate of lime) ie used, as a fiun, for the purpose of yielding linao to combine with tho silica of the ore, thus forming a fusible double silicate of lime and alumina, which appears as a slag; while the iron is separated and collected in a fluid state at the bottom of the fornace, from which it flows out at the proper time and is collected in sand moulds prepared for it, firoaucin the masses known by the name of "pigs."

As an intense heat ia required for smelting iron ores, a strong i b}ast of air is constantly injected through twyere (iron noiclea con- aectod with pipes leading from tbe blo>ving oppuisAua'i,""\cV aja

fised in hok's just above the level of tlie tyinp, or lilock of Sftud- atone, which is adjueted at the bae of the famace, tlib hhut being urged by a ateam-engine constructed for tlio purpose. By employing heated air a R&ving is eS'ected in the prooess of Bmelting, arnrit is now common to make the air trftTerse pipes which are hjiated by a sarate furnace, before it enters the blaat fomaco. Iron prapsi'ed by the hob-air process is called Iiot bligt iron, but when the air ib Mmittod to the blast furnace cold it is known as coll hlast.

Thaorudemetal obtained from the blut furnace is termed etut-iroli, of which there are throe leading varieties; —

Orey caat-iroa, exhibiting a 6nely crystalline enrfaee.

Homed eagt-iron, lighter in colour than the gi-ey, and presentiiig when broken a pocalinr mottled pearance.

WJd aal-lron, hard and brittle, Tvith a radiated lamellar fracture.

Cast-iron in all its Tarieties contains a considerabie amonnt of cubon, eometimes aa much as five per cent., together with small quantities of eilica. saljur, phosphorus, &c. These imparities nro onSised doling the conversion of the cast-iron into ierow/Jd or maMeoii! tran. This ia efl'ectcd by taking advantage of the fact, that though iron and carbon are both combustible, yet carbon is the more BO of the two : if, therefore, iron ia melted in a reverberatory furnace and exposed to a currentr of air the carbon is, to a large extent, burnt out. The operation ia called puddling, and instead of relying entirely on the action of the air to remove the excess of carbon,' a variable proportion of the oxide of iron or of maganesB is commonly employed. As the carbon passes off aa carbonic oxide the ii'oii becomes lees fusible, and ultimately breaks up into an incoherent grannlar mass like sand. The heat is then increased, those grains alatinate, and being worked up into a ball, the mass is taken from the furnace, and subjected to great pressure by machinery. The lump of malleable iron thoa obtred la then passed through a sac- ceaaion of rollers, turned by a powerful steam engine, eacb pair of rollers having a smaller interval than the preceding j by this menus the mass is grodnttlly elongated into a bar, and at the end of the rollers furthest from the furnace it passes out as the soft bar iron of commerce. Some fine examples ol such iron will be found in the entrance halL In the ordinary operation of paddling, the charge ia constantly rahbled or stirred by the puddler in order to bring every portion of the metal to tho surface. To avoid the great physical exertion thas roitiired of the workman several methods of mechanical paddling have been introduced. The most notable of these ia tho revolving furnace of Mr. Danks, in which the molten pig-iron ia agitated and brought in contact with heated air by the rotation of a. moveable chamber.

Whilst pig-iron is always brittle and oxhibita a more or less crystalline structure, the puddled iron after being duly hammered and rolled is extremely malleable aud preaents on fraturo a decidedly fibroua texture. Some specimens in Gate 51 are intei'est- ing as illuatrating a lupposed nlienifmn in the sb-ii'inre of wrought-iroa hy i-ibration. Attention was directed to tho influence of long-con- tinued vibration on the structure of iron by Mr. Nasmyth in l&l!2. His experimenta went to prove that an original iibrous or ligneous structure was changed into a crystalline one. The process of " cold Bipa//iing" was found to pritduce this molecular disturbance to so great an extent as to TMider the iron liable to break with the slightest blow. Mr. Lnoas, between thin and 1844, aiode a great many esperimonta which appeared to prove tliat Uiuft-eQu.CvvuMA vJbraCion certainly produced thia eSect, aai 'S''*'? 'M<SQ.\?aS.

120 The Musopal Flooh. 1

that even wood was subject to this -weakening influence, Bome engineers have, however, questioned the facte brought forward, and are disposed to think that the fraotnre is dependent upon the kind of biow with which the iron ia broken ;— a dull blow producing a fihroDB, and a sharp one a crystalline fracture.

A railtuay axle, as bent by an accident without breaking, and some esftmplea of peculiai'itiea ia conatruction, will be found in the Model Knom A,

Tubie-ea&o t>l: — Steel may be regarded as . Q intermediate between cast iron and wrought

on. Its principal characteristic is its capacity of being hardened V softened by rapid or slow cooling. The proportion of carbon which is present varies considerably in different varieties ; mild steel may not contain more than 0"3 per cent. , whilst the hwder tempera joajj contain nearly 2 per cent.

Steel is sometimes formed directly from the ore, as in the Catalan forge ; more i'reauently it is obtained by adding carbon to malleable iron, as in the old process of cementation ; whilst often again it is produced by the decarbonization of pig-iron, as in the BesBemar

the old process of cementation, which is well illustrated by spec ip the case before us : it will not be forgotten that a model of ateel works at Sheffield working this process, stands at the nortliem end of the room. No. 21, and ia noticed at p. 64.

In the cementation process, bars of iron are imbedded in powdered charcoal in boxes, and exposed for a long time to a full red heat. To prevent the charcoal from burning away, and to confine its action as much aa possible to the iron, the whole ia covered with some sand or earth which will not easily vitrify. In Sheffield a stiff ferrnginona mud, called tv}ieelswharf,—Ui6 stuff which is produced by the wear- ing of the grindstones, — ia generally used, and every unnecessary aperture is carefully "closed. The trough containing the iron and charcoal, which holds from 13 to 17 tons of raetal, ia then exposed to the action of fire, which is maLntaiiiod__at a high intensity for some

"Blistered Bteel is produced by the forroation within the mass of a gaaeous compound of carbon and oxygen, which occasions the foi'mation of bubbles in the metal.

Shear Steel. — Blistered iron bars are bound together, and being placed in a wind furnace brought op to a welding heat, the bars are fonned by heavy hammers into a rod about 2 inches square ; it ia then cut in the middle, the two halves placed together, and welded again as before. By this process the steel ia not liable to the flaws BO frequent in blistered steel. As the welding may have been mora or leaa frequently repeated, so the value of the steel varies, and it is known in the metal market as half shear, single shear, or donfife shear. Faggot steel is roanufactnred by a process analogous to that of shearing.

Cast Steel. — Blistered bars are broken into small pieces and put into a barrel-shaped crucible of Stourbridge clay, capable of holding about thirty pounds of metal. This ia placed in a draught furnace, which is fed with the beat coke, and every means adopted for pro- ducing a very high temperature. In about four honi-s the fusion is complete, and, being withdrawn from the fire, the molten ateel is poured into a mould. Great attention is required in this process, /Ae quality of the steel depending entirely upon the management of /Ae melter.

Sheet and Sar 8kcl, for sans, &c., ia mode bj repeatedly paeaing the metal at a red heat through large metal rollers, Sur Sled is made in a Birailar manner, the rollers being grooved to form either flat or round bars. An examination of the Model of a Sheffield Steel Manvftietory (No. 21) at the north eud of thia Musenm, irhich in- cludes the fiiniaceg. Tolling milU, and forge, will aid the Tiaitor iu forming a correct idea of the procoEsee of steel manafscture, which are here bo yery succinctly described.

In the Model Boom A, against the wall to the right hand of the Tisitor on entrance, is a stand containing epecimeiis of every variety of lied sent into the market at the time of the Great Ebchibition of 1851. These, and the model, were preseuted to tho Museum by Messrs. 2Taylo,r, Tiokera, & Co., of Sheffield.

ffardaiing and Tempurmg. — Steel ia commonly hardened by being

C.ged, when red hot, into water; it is afterwards tciiieTred by g heated until the surface assumes a tinge varying &om a light straw colour to a deep blue. An interesting series of ipeciiiiieiu of eteel af the different cotuuri for tempering will be found in this case. The process of tempering steel is one demanding the most exact attention from tho manufacturer.

Z- Before leaving this Case attention should be called to a series illus- trating tbe production of steel and malleable iron from fusion of pig-iron and hiemutite by Clay's proceae. There will also be found several examples of Muehet'e tool sled, and uumeroua fragments of ateel shot and ariaov pltiiea. In coimexian with steel manufacture it ehould be remarked that some magnificent examples of Beeeinei' aieel will be found in the lower compartment of Pedeatal-caae No. 7, and also in the case containing the Beaaemer model No. 18. A sample of Tliiticarth etecl ia placed temporarily in the lower part of Case No. 8; and a specimen of Siemejta' steel yiiU be found in tho caee before us (No. 51), whilst a model of Siemena' furnace, in which cast-steel and iron ore prodoced directly from the ore, is exhibited in the gaUeiy of the Model Boom A.

The metallurgical series haa of lato yeara outgrown the six table- cases to which it was formerly restricted, and it has consequently been found necessary to devote several cases iu the central area to this department of the collection. It is, however, nnnecesBary to allude i'urther to those caaea, since they have already received notice atpp, 59, eO, 76, &c.

Hoese-Shoe Case.

NoS-MBIililC MlNERAlS AND TIEEm ArrLICATIOKS.

Formerly tho collectiou of non-metallic minerals was co nfin ed to a large glass caao, of horae-shoc form, running round a similarly- shaped Bce in the centre of the room, which admits light to the Lecture Theatre situated below. A few years ago, however, it woe found necessary to extend this case by adding others, which are supported on the cornice of the haluatrado suiTounding the opening from the principal floor to the lower hall. The original case was divided into 16 compartments or separate cases ; 12 others have been added, thus making a series of 28 aectiona, each equivalent to an independent case. These 28 cases form a closed series, somewhat D-shaped; but though the collection has thus lost its horse-shoe form, its original name may still be oonvenieatly retained.

Id the horee-shoe case, dierefoTCitlift V\ai.toT-\&&TAsfi..'ivjR,s5sai

and ornamental atones, the spars, and earthy miucTala. These ara groiiped together under the general toi'm of " non-metallic," in coor lormity with popular nsage and practical convenience ; but the visitor will bear in mind that whilst maiJy of the species here oshi- hited are strictly deatitnte of metal, auoh an the diamond, by far the larger number contain aome metallic element, principally, howerer, the rarer metals of low density, such as potassium and olutnininm, and nevor the common heavy metals of commerce.

Each case, or separate compartment of the horse-shoe case, will now be described, conuneneing with the case at the aonth-east corner of the aeries.

Case a.— Diamond.

From the high refracting power of the dianiond, Sir Isaac Newton oonjectnred that this beautiful gem might be a cornbustiblo body. In the heat of the oxyhydrogen flame, and in osygen gae, the diamond has been burned, prodaeing only carbonic acid gae, and leaving a small quantity of ash; and by the electric are it has been converted into a coke-lilie mass, thus proving that this hard trans- parent body ia only carbon in a peculiar form.

Diamonds are fonnd natnraliy crystallized, the forma always being related to the cube ; the faces ore usually rounded as seen in many of the crystals esliihited. Diamonds have been, throngh all time, discovered in the- East Indies, espenially in the kingdoms of Golconda and of Tisapour, but the largest supply until lately was obtained from the mines of Braail, where they occur chiefly in a deposit called caseaUio, consisting principally of fragments of qitarta and ferruginous sand: a sample of this caacalho is shown. Unpa- ralleled discoveries of diamonds have, however, been made within the last few years in Sonth Africa. The first diamond was found in the Colesherg district in 1867, and was sold for 500i.; a model of this etone is exhibited. IJarge numhera of diggers were soon atti'acted to the fields, and their labours rewarded by the discovery of vast nnmbera of diamonds, including many of unuanal size.

The largest yet discovered is the celebrated " Stewart," of which a model will he found in. this case ; the original weighed 288J carats, and was found at Waldeok's plant on the Vaal Eiver. Like a large proportion of Sonth African diamonds, the Stewart exhibits a pale straw tint. The African diamond workings are of two kinds, known as the " river diggings " and the " dry diggings" ; specimens from, both are here exhibited. The river diggings are in deposits of gravel, rich in pebbles of jasper, agate, &o. ; whilst the dry diggings are generally opened in disiategraled material occupying pipes which breaJc through the Karoo shales. The diamonds are occa- sionally fonnd attached to fragments of associated rocks, and several of such stones in the " matrix " will be found among the specimens in this case. There are also exhibited nnmeroug examples of the pebbles and other materials among which the African diamonds are found, whilst the character of the workings at the gi'Cat Colesberg Kopje is well shown by the photographs at the back of the case.

Many of the largest known diamonds which have acquired historic interest are here represented by models, among which those of the celebrated Koh-i-noor claim especial attention. This diamond is, according to Indian traditions, more than 4,000 years old, having been fonnd in the mines in the south of India in the days of the great war celebrated in the heroic poem, the MahSbharata, and was irorn by one of the warriors who was stain on that occasion. The Itajah of , 50 B.C., is said to tore Viai twaesinro. yoia

Hobse-Shoe Case 123

gem, and it remained witli his BucoeBsors until it fell into the hands of the Mohammedan conqnerorB of India.

In 1665 this jewel was examined by Tayemicr in the cabinet at Delhi, and in 1739 Nadir Shah, on his occupation of Delhi, obtained possession of it. After his death the diamond, which he had wrested from the unfortunate representative of the house of Timur, became the property of Ahmed Shah, the founder of the Alniali dynasty of Kabul, who probably took it from Shahrikh, the young son of Nadir Shah. The jewel descended to the snccoiisors of Ahmed Shah, and was worn by Shah Shuja on his arm. When Shah Shuja was driven from Kabul he became the priBoner of Bunjet Sing, who compelled the fugitive monarch, in 1813, to resign the precious gem for, it is said, a lakh and twenty-five thousand rupees, above 12,000Z. sterling. Eunjet wore the diamond as an armlet on all great occasions; after his death it was worn hj Ehurreuk Shing and Shu Shing. After the murder of the latter it remained in the Lahore treasury until the supercession of Dhulip Sing, and the annexation of thePunjaub by the British Govemment, when the civil authorities took possesion of the Lahore treasury, under the stipulations previously made that all the property of the State should be confiscated to the East India Company, and that the Koh-i-noor should be given to the Queen of England. In order to briug out its lustre and remove some flaws, this gem was re-cut after the Great Exhibition of 1851, under the direction of Messrs. Garrard, and since the cutting its beauty has been greatly enhanced.

In this case will also be found mods of the following diamonds, the weights and approximate values of which are expressed on the accompanying labels: — The Bajah of Mattan's; the Star of the South; the Mogul; the B>egent, Pitt, or Orleans; the Orloff, or Bussian ; the Tuscan ; the Florentine, or Austrian ; the Hope ; the Dresden ; the Nassuck ; the Pigot ; the Shah ; the Sancy ; the Eugenie ; the Polar Star; the Cumberland ; the Stewart ; the first diamond found in S. Africa ; Mr. Dresden's ; the engraved Persian ; and a diamond said to have been worn by Napoleon in the hilt of his sword.

The impure variety of diamond called hort or hooH, which occurs usually in small spherical nodules, having a radiated internal struc- ture, is employed, in the state of powder, as a grinding and polishing agent ; and the darkoloored non-crystalline substance called **c(irbon*' or ca/rbonado receives a similar application. The latter is a peculiar form of carbon, discovered in the diamond gravels of Brazil in 1842, and appears to furnish a transition from ordinary diamond to the next species — graphite.

Case B. — Gilajhiie, &c.

The mineral known variously as GrajiJdte grailiOy I write), FlwYihago {Plumbum, lead), and Blacklead,'* is composed of carbon and a small but variable quantity of iron ; it has, however, no chemical relation to lead, as some of its names might suggest. It occui's in beds and imbedded masses, in granite, slate, and crystalline limestone, and in nodules in greenstone. It is occasionally found crystallized in thin six-sided plates ; and a similar form is assumed by the a/rtificial graph ito or Kish" formed during certain metal- lurgical operations. Examples of this are exhibited.

The plumbago from Borrowdale in Cumberland has long been

1S4 THB. FBINeiPil. FLOOB.

mineral being found only in detached pieces, called, according b(f their size, sops or bellim. Some years since iv rery largo qiianti of plumbago was obtained from Borrowdale ; this has been etored* by the proprietors, and sold in small parcels from time to timo, Tne mine was not worked for several years, but liaa been reopened'

The application of plumbago to the manufacturo of crucibleB having Men already noticed (p. 46), it remains only to inentioa its aae in the preparation of black teaii penBiU, as iiluatrated in this

Pencils are of three qualities, — drawing pimcilx, prepared pmcilt, and cornipoaition pencils. Pencils of the first qiialily are made of pure Cumberland plumbago, which oosta about I68j. per cwt. They are made Ly sawing the "had" into pieces, and msertini- them in the cedar, A pound of plmnhago will produce about 11 or 20 dozen of pencils.

Pencils of the second quality are manufactured out of the sawings or duat of pure black lead, and the small pieces which could not be cnt into pieces of sufficient length ; this is mixed with a certain quantity of antimony. The antimony ia frequently in large exoesa above the black lead, the former coating only 2Gs. the cwt., the latter 1001. The third qjtalitij of pencil is made with Meaioan or Spanish plumbago and antimony, sulphur being added to produce the blacker pencils.

By Brockaion's Fiiieiit, illnsti"ftted in this case, the smaller pieces of the Cumberland plumbago, which are too small to be cut into elicea for pencils, but are yet. of veiy fine quality, are ground to an impalpable powder, which ia subjected to enormous pressure, impartedbymeanaofaacrew press. The result of this is that the plumbago powder ia rendered perfectly coherent. EVom the blocks thus formed, some of which are shown, slices are sawn, from which

?Bucila of the beat quality, and entirely free from grit, are formed, he fracture of this compressed plumbago precisely resembles that of the natural graphite.

In addition to the Cumberland graphite, specimens of the mineral are eshibited from Siberia, Ceylon, and Canada, as well as from several other localities of much less commercial importance.

The remainder of this case is occupied with some of the forma of coal, which are rich in carbon. The " motkef of coal" or niineral charcoal, which often occurs between the layers of bituminous coal, ia a soft fibrous material, readily soiling the fingers ; it contains between 75 and 83 per cent, of carbon. The varieties of coitfl repre- sent the carbonaceous constituents of coal as obtained artificially by processes of destructive distillation. There are also some samples of the so-called " graphite," or gas-carbon, fouiid lining the interior of gas retorts, and valued as a conductor of electricity ; it is sawn into pencils to form the poles between which the electric light is produced, and it is also nsed as the negative element in Bunsen's battery.

The rarieties of coal, occupying part of this case and of the nest, form a regular series, commencing with the non-bitnminous stone- coal or anSiracite, and passing thence through the ordinary bitumi- nous coals to the recently-formed lignite or brown coal, in which die original structure of the wood ia frequently retained. The probable mode in which coal has been formed is noticed at p. 174.

Atttliraaite always contains a large quantity of carton, frequently apwarda of 90 per cent., and but a small proportion of volatile con- BtiiaeatB. Ab the anthracites become softer fce-j wm 4\4\iVD?ji.\a\ied

Wmisk-Shoe Case. 125

&a free-bunt! 11 eoals, and tliese may jiass into the ordinary hitumiaoiu Torieties, as in the Sooth Walea coal-field.

The " eryat(Jli-:eil " coal eshibita a very peenliar stroettire, known aa cone-in -coiie; and In the peacock coat, provinciaily eallcd moontong, we have a reraarkable example of the iiifliieDce of surrace arrange- ment in producing colour.

CiSE C. — CoiL, Jet, Avbeb, Ac.

A large part of this case is occapied by a oontinnatioQ of the series of coals, and by varions hydrocarljone more or leas cloaely related to this Bories.

Cawiel ia nsually regarded as n hard, corapact variety of bitnmlDous coal. It bams readily without racttiiig, with a clear yellow flame, oud it has been used as a subatvtuto for candles, whence it name, randle, or, iu local patois, eannul coal, Large quantities are raised near Wigan in Lancashire, and at Lesmahagow, about twmty miles from GlaBgow, where it is mode into iakatauds and other ornameatal nrticles. A fine block of Lancaebire cannel stimdd ia the Lower Hall, No. 50.

The ABiertile from Nova Scotia appears to be an asphaltic variety of cannel, but ita right to be called a "coal" is certainly ques- tionable.

Lignita or hrouin eoal, which frequently retains the original teiture of wood, nsnaUy occurs in deposits of tertiary age. In (Jennany lignite ia estensively worked, bnt in this country it is raised only at Boyey Tracey, in Devonshire, where it occura in beds of meioceae age. The value of lignite as a fuel is far inferior to that of ordinary pit-coal. The meiooene plants from the Bovey-Tracoj cannel will be found in the Upper Gallery, Case 62.

Jet appears to be a compact variety of lignite. At Wbitb)- the jet occurs in the upper-lias shale, from which it ia collected with great labour. It is also found oo the shore, beiug freiuently throwTi up after storms. lEuch of the common jet is now imported from Spain. Jet ia the gaijatet of Pliny, a nam derived from the river Gagaa in Syria.

With the coals are introduced a few minerals, or rather rock- Bubstanoea, which, although ditfering essentially from coal, nerer- theiesa poasesa conaiderable economic value. Of these the most interesting ia the Toi'hane Hill wineral, or " Sog Mead eannel," found ia the coal-measures of Linlithgowahire. From ttis eub- stance, which ia well known as baring been the oaaso of considerable litigation, are obtained, by distillation at a low temperature, certain hydro-carbons highly valued, partly for illuminating purpoaea and partly aa lubricating agents. It is now, however, virtually worked out, and recoarse is had to other shales in the district.

The so-called Kimeridje coal is a bituminouB shale occurring in the Kimeridge clay of Dorsetshire. When heated to redness in the open air the organic matter ia alowlj burned away with a smoky flame, and a bulky aah remains, consisting principally of alumina, the quantity of which is so large tliat some of the shale has been used as a source of alnm, and a former posaeasor of the property erected works for this purpose, If, instead of being heated to red- ness in the open air, the shale be heated in a closo veaael, a variety of valuable gaseous or liquid compounds may be distilled off. Small circular disca of this Kimeridge shale are frequently fouud in the Isle of Furbeck, and from their supposed use pasa under the aante of Kimeridge coal wiOJiey, but it ia taOTft YAiWife Co.'i,

Tw Thb Muncipm. Floor.

ore eimply the refase-pieoes from which rings oi- aj-mlets have beea-. turned.

The TQinaii&der of this aeotion is occupied by certain organic aoia.-' ponnda, which require no very special dcsoription. Satcketiine or. mineral ialloie ia a, hydro-carhon oocnrring in the nodnlea of clay ironstone from the Sonth Walea coal-field ; and Ozokerite or minei-al tcaa isa snbatanco of Tory similar composition, found in considoralile .1 quantity in Moldavia, where it ia apphedby the peasants to a variety of purposes, and whence it has of late been largely imported for the prodaction of paraffin and the manufacture of candles by Messrs. Field & Co. Olosely reJatcd to these are the substances groiraecl il together under the genera! nnme of Bitumen or inineTal piteh. The compact variety called Ahall is represented by specimens from the mountain limestone of this country, and from tha celebrated Pitoc Ie of Trinidad. This lake is one and a half miles in cironiii- ' ferenoe ; the bitumen is solid and cold near the sborcB, but gradusJly inci-eaaes in temporatnre and soilness towards the centre, where it is boiling. The solidified bitumen appears as if it had cooled as the surTaee boiled in large bubbles. The ascent to the lake from tho sea, a distance of three rjuarters of a mile, is covered with a hardenod pitch, on which trees and vegetables flonrish ; and about Point la Braye the masses of pitch !ook like black rocks among tho foliage ; the lake is said to be underlain by a bed of mineral coal.

The Elaierile or mineral eaoviehotte is a soft elMtic variety of bitumen having a peculiar odonr, andoccnrring in the carboniferona limestone of Derbyshire, where it was first observBd, at the forsaken lead mine of Odin, bj- Dr. Lister, in 1673. Passing over a small group of mineral resins, found chiefly in deposits of lignite, tho only other mineral which need be noticed in this seotion is the well- known substance Amlm:

The vegetable origin of amber is now fully ascertained. This ia inferred both from its native situation with coal, or with fossil wood, and from the oconrrence of insects and other organisms encased in it. Of these insects some appear evidently to have struggled after having been entangled in the then viscous fluid, and occasionally a leg or a wing is found some distance fi-om the body, which had been detached in the effort to escape. Giippert has named tho tree euppoaed to have yielded most of the amber Pinifes Buccinifer. The principal supply of amber is obtained from the Prussian coast of the Baltic. It is also found in Sicily.

Such ere tho examples of natural substances belonging to the carbon group, commencing with the most brilliant of gems, passing through all tho varieties of coal, and terminating with another substance used for ornament, amber.

The coal-fields of England are the most important in the world, the production from British collieriea during the year 1874 having reached the prodigious amount of 125,000,000 tons.

Case D.— 2fATrvE Euithcb. j

Sulphur is one of the most widely diffused chemical elements in the economy of nature. In a free state it occurs chiefly in volcanio districts ; Sicily and the neighboui-ing volcanic islands, and the Solfatara, near Kaples, being the gi-eat depositories from which it t is obtained. There are also important deposits in the Bomagna and in Spain ; vrhilst the snlphur of loehmd has recently attracted atteation commercially. Most 'of the sulphur-yielding localities are ire]i represented ia the c£i6e before 'ua, ar.4 aevevaV o? 'IjVkbi. \iBra

HOmE-SRQE CASE. 127

oontributed fiuoly-crystallizedflpecimeika- Tho visitor will Mporiitliy note tho largo cryaUla from tho UoraaipjB, from Spain, and froia Sicily, where the sulphur ia aaBOciuted iriLh eclestina uid gj'pBiini.

CiSB B. — Pbepahed SiTtPmrn.

Tho extraction of Bulghur from tho iinpuro nutive mfttriuU, aud the properties of the prepared siilphar, ore illustratod iii this cue. As native sulphur ia asuollj contaminated wiLh enrlhy niatton, it ia pnriSed bj a simple proceea of diBlillatioa. SnlpbiiT is aUo Ui'Kelv extracted from iron pyritea (p. 108). a biaulphido of iron, wbicli yields a coneidcrable proportion of free aalpliur on sitnplo dii. tillation.

At ordinary tempoTatnres BulphorexistHaaan opaque solid of spci- fio gravity 1"98. It melts at 21i£t FaL. to an aniber-colourod IJLiiiid; if the temperature be then raised to about 400" Fah. it beoomoi dark brown, opaque, and eo thick that the vessel containlngjt may be in* verted without its runnng out; but heated yet higher it again uecontea thin and limpid. If the thick tenacious sulphur at 400 bo suddenly cooled by immersion in a large quantity of water, it forme a soil and transpareot mass of consiaerable elasticity. In this state it ia used for receiving intpreeions of teals, &c. i after saiai time it changes into its ordinary state.

The cryetals of native sulphur, and those prepared by evaporation from solution at ordinary temperatures, are entirely diatiiicl In fonu from the mystals which may be obtained by sobdificatioa from a state of fusion ; and this dilfcrcnce in crystalline charactei- 'n ac- oompacied by a corresponding variation in dcDsity and other j>hj8ical properties.

With the Httlphur-group will be found a fine spociiiien of tho cloaely-allied hut much less widely -diflused clement, mhitium, aa

Spared from the deposits of the coppor-s melting fuinacea of nafeld (p. 111).

Ciss Tf. — Saus ov Bomcu ; BoBicic Acid. A large specimen of orystalUzed toilvum ie exhibited in connexion

with the alnminiiun-Mriea on the opposite side of the room; and another specimen is placed here as repreaeitting the metaliic baae of a group of minerals which occupy a prominent position in this section. Of these salta of sodium, the moat important is the chloride or eoiiimon eait. The greater part of our cnliniiiy salt is manufac- tured from the brine spriugB of Chesliireand Worcestershire, which rise probably from beds of Rock salt. The rock salt itself ie hugely worked at Northwiob, in the valley of the Weaver, and near Belfast, in Ireland. A thick bed has been pierced at a considerable depth u Middlesbro'-on-Teea. Tho rock salt of Cheshire oocurs in stratifi deposits near the bate of the New £ed or Keuper Marls, associated with gypsum. Occiwionally the salt ia ooloui'loas and crystalline, but usually it is oOloured to a greater or less extent by the presence of peroxide of iron. Although generally found in tho New Bed Sandstone, rode salt ie by no means confined to this formation; the deposits, for example, of Wielicaka, in Poland, and Volterra, in Tnacauy, oocurriug in tertiary marls : fi'om both thesB localitiea speciuieiiB are exhibited.

The onriouB hop per- shaped crystals of salt hei-e shown rcauit from the aggregation of a number of small cubes formod on the surface of the brine during eva|ioration.

The Greeuhiud mineral caUei CnjoUte "Ji: "itc-aloiw "w. JiRwlti*

flaoride of alumininai and sodium, which, has been already noticed as a source of aluminium {p. 76).

The few remaining salts of sodium, here eshibited, require no lengthened description. Attention should, however, be directed to the unnsaally fine crystala of the rare mineral called Olaubfrife, a donble sulphate of soda and lime, from. Spain. The deliqnesoent nitrate known as Ouhic ni'Cre is employed as a source of nitric acid, and in other ways as a BubBtitato for saltpetre ; while the borate of soda or Boria:, known in ita crude state as Hneal, ia largely used for soldering, and for glazing pottery. From boras we pass to boraeic aoid, of which a snaatl groups of Hpeounens ia here introduced.

This acid, a compound of boroa and oxygen, ia obtained for the arte from the volcanic fumarolea of Tuscany. The firat locality known was at Saeso, whence the name eaaaoUn, The lagoons of Tuscany spread over a surface of about 30 miles, and clouda of vapour are constantly seen rising in large volumes among the mountains. Aa they are approached the earth appears to pour oat boiling water, as if from volcanoes of various sizes, the beat in the immediate neighbourhood is intolerable, and the vapours suETocat- iag ; the vents for the vapour are termed eoffimti. These hot vapours, which contain only a small proportion of boraeic acid, are made to pass through water, by which the aoid ia abaorbed. This weak solution gradually heoomea more highly charged, as it is'.transferred from one lagoon to another, and, when sufBaiently impregnated, the solution is evaporated by means of the steam from the springfl. The specimena exhibited are from the worka of the late Count Larderel, whose name deaerves record aa tho founder of this branch of industry in Tuscany.

Among the Baits of boraeic acid may be noticed Hayesine, a borate of lime, occurring in white reniform masses, scattered over the dry plains of Iquiqne in Southern Peru, where it is called Una.

Case G.— Sai/k of PoTASsnjM, Mabnesiuii, &c.

Of the Baits of potasstuiu only a small number occur native. The chloride of potassium, corresponding to rock salt in the sodium aeries, was an extremely rare species until found a few years ago in the salt-deposits of Stassfurt in Prussia. Some fine crystals of this mineral, known as Sylviiie, are here exhibited. The nitrate called Nitra or saltpetre ia of considerable value, being extensively employed in the manufacture of gunpowder. In tbe East Indies and in Ceylon a great nnmber of nitriferoua caverns esiat, but the spontaneoiiB generation of nitre in India, Egypt, Spain, and elaewhere is inaoffi- cient to supply the wants of tne world, and a large (juantity ia therefore prepared artificially. Nitrate of potash crystallizes in six- sided priama, with four narrow and two broad faces, as may be well seen in the artificial crystals.

Alum is placed here as a salt containing potash and alumina in combination with sulphuric acid and water. Such at least ia the composition of ordinary alum, but in other varietiea the potash may be replaced by soda or other protoxides; indeed of late years themanu- fature of ammonia-alum baa largely superseded that of the potash salt. Alum waa long manufactured on a large scale from the aium tlate or ehale of Whitby. On roasting this ahale, the disseminated iron pyrites undergoes decomposition, a portion of its sulphnr being canrerted into aulpbnrie acid, which forms a aulphate of iron and alumiaa, and on decomposing this by a eaVt oS ''''si- cdnnQoii n-m.

]

Hohse*Shoe Case ' 120

18 obtBiiied, TliB shalo in various atagea of decomposition nnd soiiio fine alam erj-stala are here shown. The manufacture of Whitby alnin ia, HoweTer, alioost discontinued.

The Hungarian alwinglone ia an altered trachytic rook, not only used aa the eourceof a very pure alum, but also employed occusioiiallv as a millstone.

Websterite, a salphato of alumina, discovered by Mr. Webster, ihe .gedogiat, at "Wbitehaven, in Sussex, ie represented by Tariona speci- mena which have gained admission hero simply by their rather remote relationship to the alnm group.

An intoieBting series of minerals from the salt-deposits of Stasa- ftirt is placed in this case. Borings for rock-salt in the neighbonr- liood of Stassfttrt. near Magdeburg, in Prussia, revealed the Biiatence, some few years ago, of vast deposits of various salts of potassium overlying the sodium salts. This represents precisely the order in which fliey would cryatallize from a solution containing both kinds of salt; the salts of sodium being loss soluble than those ofpotassiam and magnesium would separate leaving the more BDluhle compouuds in the mother- liquor. The diacovery of the £aliealx of Stasafurt has entirely changed the sources from whence the chemist derives his supply of potash salts ; it has developed very flourishing local iudustriea, and has furnished to the mineralogist several new species which are ropreBeoted in the case before us.

In this section are also placed a few minerals containing inajne- BM*m, Bach as Bntcile and Epsoiiilta. Although magnesium was discovered by Sir H. Davy in 1H08, it is only by Mr. Sonstadt'a com- paratively recent improvements in its manniotare that it has baen obtained in quantity sufficient to render it of commercial importance By the action of hydroahloric acid on carbonate of magnesia there ia obtained a chloride of magnesium, from which the metal is rsducod "by the action of sodium. Examples of the metal will be found in Case No. 46.

Case H.— Salts o? BiHinM in-d Steonttuk.

The very widely diffused mineral Bweyies, or sulphate of bairta, is frequently employed as a pigment, either alone or associated with white lead ; and for this purpose the mineral is raised in Derbyshire, the Isle of Arran, and other places. Prom its density barytea ia commonly known as heavy epar; while the massive earthy varieties often pass under " " '" '

remarkably fine cryataf ham, in Northumberland.

Carbonate of baryta combines with carbonate of lime, forming a, double salt, which, occurring in two distinct series of crystalline forma, gives rise to the two species bcnrytc-ealcUe and alsionite.

The earth atronlia, closely allied to baryta, occurs in the form of Bulpbftte and carbonat-e. The sulphate called Ceiatfiras, from the pale blue colour which it occasionally presents, occurs in fine crystals at Girgonti, in Sicily, aaaooiated with native sulphur ; and in the neipibonrhood of Bristol, in the New Red Marl.

The carbonate known as Stro'ttianite is found in the lead mines of Btomtian in Argyleshire, a locality which has given its name to the mineral.

The salts of atrontia ore remarkable for the red colonr which they impart to flame, those of baryta giving a gMBU *,\iit.

40332.

raWGIPAt PtOOB.

CiBE I. — , &c.

Ireadybeeft

1 with the case in the lower Hall, illuetrjiting

applicntiQUB ot plaster 0/ Jam, this salt of lime has already b

deacribed (p. iSj. The crystallino character of Gypumi, or, aa the-' tranaparent Yarieties are called, Seknite, is well shown by theal perfect crystalH which not unfroguently occur in depogita or clay and marl ; a characterietic twin-mrm being Been in the fine arrow- headed crystal from the celebrated quarries of Montmartre, neM- Pfa-is. Ttie beads and other objeote of fibrotit gijpgum, eihibft in a marked degree the pleaaing lustre which has led to the luuna. ot ioliti e'ur ; whilst the ciirving executed by Mr. Jordan's machinoiy yjustratea the application of the variety called aialaster, degcribeft at p. 34. The waterless aulphateof lime, Jiii/drife, has been alresidy noticed {p. 43).

Cabb J. — Calcite. Some idea of the great rariety of forms assnmed by this widely'- daatribated mineral will be gained from the numerous crystaUiaSfl fipecimens grouped together in this secticm. On fracture, tl '" 'stala of calcite split with the utmost ease into regular Bix-aid ids, called rhombohedrons ; and it was indeed in this speclM .t the property of cleavage in minerals was first observed. Ool- _CBreoua spar is a carbonate of lime, containing, in a state of purity, 'rbonio acid, 44 ; lime, 56 ; but it often contains impurities upon _Tchicb depend the colours aasamed by the mineral. The highly transparent varieties are termed Iceltiid spar, th6 finest specimens being obtained in Iceland. This crystal is remark- able for its double relraction, the phenomena of which are weB ehown in the specimens oxhiliited. The power of refractine light doubly is, however, enjoyed in a greater or less degree by orygtline minerak, e3:cept those belonging to the cubic stein<

Case K. — Oabbonaie op Limb, ooTilmueA-

Many of the massive forms of carbonate of lime having b sJrendy described in oonceuon with the marbles (p. 30) and A Btoties (p. 37) in the Hal!, it only remains to notice among marbles here exhibited — the gitUlo antieo, or yellow marWe Bienna, generally known as Sienim marbi the onya marble, froa] Algeria and Mexico, a stalagmitio form similar to le ' ' alabaster-'' of the ancients; and thejire marhlrs, or lumachella, from the lead mines of Bieiberg, in Carinthia, remarkable for the brilliant irideaceuco of its fossils.

The Derbyshire ialaid marble work in imitation of Florentu' mosaic is sufficiently esplained by the descriptive labels attached.

The FontaiitdiUaii scmdelone or HmeBloiie ia an aggregate of rhoDfc- bohedi-ons of carbonate of lime, containing a large quantity of sanft mechanically mingled.

' I In connexion with the varieties of carbonate of lime will be fonoi' some interesting eiamples of the production of fewrls on the shw of the pearl oyster and pearl muaael, by the artificial process <lf introducing some object which will produce irritation to the moUnso'

A very distinct physical condition of carbonate of lime is prssentecl in the mineral called Aracmite, from having been first discovered' at Aragon, in Spain. In addition to the fine rhombic crystals n be noticed the coral-like stalagmitio forms ocourring chiefly in ires mines ofStyria, and knows aa Jtos ferri, or "Jtom&r 0/ iron."

H0H9E-aH0E CASE, 131

Case L.— Dolomite ; ArAittE.

OEvbonEtte of lime frequently coDtains a variable ftmoDnt of oftr- iKmato of maeeia, and when the two componiidB occur united in nearly eqaivatent proportions, Chej form the speoiee Dohmife, already described among the baildin atonee (p. 39). Afi Uie proportion of magneeia inoreaseH, tho species passes into MagnenUe, or cftrbonate of magnesia.

The remainder of tbis case is acnpied with a series of specimens ninetrating the vurieliea and raode of occurrence of the ralaable xni&eral called Apatite.

In different varieties the oompotion of apatite varies, bot it cdb- easentiallj of jihoaphate of Ume asaociated either with a chloride or fluoride of calcium, or with both. This mineral is not anfre- (Aentlj found in company with tin ores. The oitenaive ose of phosptate of lime as a fertilizer gives considerable commercial valne to the deposits of this mineral oocnrring in Spain, ffaasau, Norway, trad Oanada. A fine example of Oanadian apatite is exhibited in tfae Hal], No. 168. p, 48. The massive varieties are frequently ealled Phoephorile. With the minerals in tbis caae are grouped a few other OBphatio suhstanoes applied to similar purposes. In the lias, green- mud, and other HBCondary formations numerous eopvlitea and -'-"

phatio nodulee occur ; andinsomeof the Crags of our eastern ci they are also found, with various mamoialian and other animal remains, the action of sulphuric acid these are converted into Haper-phosphate of lime, in which form they ere largely employed tot manure. Yalnable phosphatic deposits have also been diaeovored in North "Wales. The well-known Peruvian guano and the West Indian somimrite find a place in this group.

Case M. — Fluob Spab.

The species Flv,or epa/r is here represented by a number of speci- mens, not leas attractive by their variety of colour than by their heauty of crystalline form. The mineral, which is a fluoride of cal- cium, containing fluorine 48'7, calcium 51'3, is found abundantly in nearly ail our mining districta, especially in Cumberland and Derby- Bhiro, Devon and Cornwall. Its chief uses are as a flux in certain metallurgical operations, and as a sonroe of hydrofluoric acid.

By acting upon powdered fluor epar with sulphiirio acid, hydro- fluoric acid is liberated, and may be used to etch glasa, which it attacks with great energy. A five etching executed in thjB manner will be found in Case 56, p. 156.

The violetblue vEiriety of fluor known commonly as " Blue John," ia used in the manufacture of ta/ze, aa shown in this caae, and of vases aa eshibited in the Hall. The visitor will not overlook the magnifloont vase No. 19, described at p, 63.

Being slightly soluble in water containing bi-carbonate of lime in solution, this mineral often disappears from the iodea in which it previously existed, leaving moulds of its form filled with other minerals, or coated by them. See such examples in Wall-case 84.

Case N. — QuAaiz. Occurring under a greater variety of aspecta than any other member of the mineral kingdom, the species Quartt: necessarily claims a largo amount of space, and hence it estenda through thia and the two succeeding cases. Pure quartz consists simply of silica, or oside of silicon, Tiie mineral oryataWiiea -x™--

132 THE pRnrcrPAi ixoob.

lihe rhotnliohedral ajstem, aad is sufficiently hard to scratch gl( Tiitli facility.

Bock crystal is a pare tranapareut variety, frequently enoloBing mtile, chlorite, various fluids, Ac. Small brilliant crystals are oftea locally termed "diamonds;" such, I'or exarople. are the so-called! Corniah diamonds, Bristol diamotids, 4c. Under the niuiie of " white stone," the mineral is occaeioiially employed in jewellery, those crystals being valaed which contain slender prisms of mtile, or oxide of titanium, known to the jeweller as Jleeltes iTwmiour, or Love's amnm. A more useful application of rook crystal is a for- mation of " pehble " lenses for spectacles. Thin fibres of aabestoB (p. 137) penetrating the quartz give rise to the remarkable Instre of' the cat's-eije, a mineral obtained chiefly from Ceylon,

Smoky qaa/ris is a variety presenting a brownish tint, the term mwion being applied when the colour becomes iatenae. The trans- parent brown and yellow crystals form the well-known Scotch stone called from its locality eairronn; whilst the bright yellow varietieB are distinguished as citrine or /aieeiojraz. Atnetkyst is another form of crystallized quartz, usually presenting a purple colour, due pro bably to the presence of oxide of manganese or of iron. Amethjato of the finest quality are found in India, Ceylon, Persia, and Siberia. Tlie pink colour of roie qua/rU is probably referable to a Klight ad- mixture of oxide of manganese.

Case O.— QTTAaiz, conHnved. In this cose the varieties of quartz are continued, and the s passes from the crystalline to the ohalcedonic and iaspory forma of this Protean species. The eye will be arrested by the gold-spangled appearance of the Aveniiu/rine, which is probably due to the pree of miuute scales of miCa. The aventurine glass will be alluaed p. 163, In ihe fsrruginoiis gwirtz, or Eiseihiesel, the mineral is deeply coloured, and usually rendered opaque, by the presence of hydrous peroxide of iron. The specimens of capmd fptartx cariously show how a deposit of quariiz has been throvra aown upon a crystal of the- same substance, with sufficient interruption to preveut perfect cobe- sion between the crystal and its cap ; whilst the mmidtmiorphi of

Suartz suggest changes by which various minerals liave impressei leir specifio forms upon the quartz, or have suffered removal, whilst the quartz has taken their place.

Chalcedoni/ is a translucent vai'iety of quartz, of a was -like appeai . ance, occurring chiefly in stalatitic forms. It has beenregarded aa a mixture of ordinary quartz with opal, or soluble silica. Many of our moat beautiful siliceous minerals are simply coloured varieties of chftlcedony ; oxide of nickel, for example, producing the apph green tint of the ekryeoprase, while pecoside of iron gives rise to ih, bright red tint of cornelian, and the deep reddish brown colour of sard. These varieties are well represented in this and the following

Case P,— Qdaek, coTilinved. Some beautiful examples of chalcedonic and jaspery varieties of quartz are here grouped together. Eegular alternationa of Jight aud dark coloured chalcedony are presented in the onya, and on this depends its value for cameo work: when the layers consist of sard Juxtaposed with strata of white chalcedony, the stone is called

la the moss agate and moclia stone tte iea&fAw ot HKsa-VJifi 4e.-

Hobse-Shoe Case. 133

Uneationa of an opaque browmah yellow or green colour are mostly due to oxide of manganeBe or of iron. The ordinary forma of agate are represented to a limited extent in this case, Lut are fully iUua- trated in the succeeding section.

Passing from the cholcedoniea we find another group of siliceous miiiarala formed by the jaspery varieties of quartz. When the coloUTB are in stripes it is called ribbon jasper, of which some Siberian specimens are hero exhibited. In the Egyplian ja-ejier, whioh occurs usually in the form of rolled pebbles, tha brown colours are disposed in concentric aones. Seliotrope, or b!oad-stHe, is a jasper of a deep green colour, interspersed with blood-rod spots, fonnd in Silesia, Iceland, and the Island of Bum, Scotland,

Cask — Agates. Although a few examples of agate are placed in Case P., and a fine apeuimen stands at the southern end of the room Ko. 5 (p. 56j, it baa yet been considered desirable to devote this case specially to the display of agates, so as to fully illustrate the varieties presented by this beautiful stone, and to explain aa far as possible their mode of DDDurrence. The beauty of the varied forms of agalfS depends chiefly on the alternation of difi'erent varieties of chalcedony and jasper. The agates are invariably found in the cavities of igneous rocks, akin to basalt, but generally associated with palieoEoic strata. It is probable that the maengagement of gas or steam produced pear-abaped cavities in the igueous rock when in a fluid condition. Mid that these hollows, retained by the viaoositv of the lava-like rock, have been since filled, partially or entirely, by silica and other BuhatBEces deposited upon the walls of the cavities from solution in the water circulating through the rock. Many of the specimens in tiiifl case were selacted by Professor Woggerath, ofBonn, with the view of showing the inlets of infiltration through which the ailioeous liquid is supposed to have gained access to t£e interior of the stone, and to illostrate other points in the genesis of agates, which are sufficiently explained by the labels accorapanving the speoimena. Heference has already been made (p. 56) to the chief localities of agates and to the agate-indostry which is centred at Oberstein. It remains only to be said that most of the agates of commerce are coloured by artificial processes, such as boiling them in oil or syrup, and subsequently treating them with sulphuric acid ; the oil or augar is absorbed into the more porous layors, and then carbonized by the action of the acid ; thus the artificial dark-colovu'cd varieties are formed. By first boiling agates in solution of proto-sulphate of iron, and then exposing them to heat, by which peroxide of iron is formed, the red varieties are prodaced. For detaila of the proceaa reference mbe made to the article "Agate" in Dre'aDictiojwrj, 7th ed.,

The quarta-family is here brought to a close by a few minerals, for tbe most part less attractive than those already noticed. Ordinary sandstone has been described ia conneiion with the building stones, (p. 86j. The jlexUile aaiidsioiie here exhibited ia a remarkable variety, the flexibility of which has been referred to the dissemination of email scales of mica through the mass. Several compact forms of silica are presented in the shape of hortiatone, chert, and JUnt: ia flint the silica appears to \jeraU's\ii'CQB'sf3\Aivt uad partly In tbe insoluble state. Ita occrai cVw-j "m- *ib Q.'ii{v

134 THE PKINClPAL FLOOR.

chalk, in the fonn either of nodtiles or of regnJar bands ; Boma ohoraeteriBtic speoimena will be found among the rock-speuimena ix. the appor gaUery. Some of the applications of flint reoeive illni*' tration here, and a collection of early Sint implements is srrange4 in a table-case Ko, 15 on the opposite aide of the room (p. 61).

In the mineral oalied Opal, which ia generally regarded as speci- Soally distinct from ordinary quartz, the silica exists in an amor- phoiis, aoloblo, and nsuany hydrous condition, having solidified probably from a gelatinonB state. The nobh or preeioaa Ofol haa always been a mnoh valaed gem. The Orphic poem commenda the opal. Baying it haa the delicate complexion of a lovely youth. This gera, Pliny says, the Indiana so well imitoted in glass that the counterfeit could hardly be detected. He also telle us that a senator named Nonius posseesed an opal valued at twenty thoueond BBBtercea; that Anthony proscribing him, he fled, saving, of hia whole property, this ring only. The preciowa opal occnra in por- phyry at C/erwcnitza, near Eaabau, in Hungary, and under similar conditions, in Hondnraa. The fine specimen from a recently diat covered locality in Queensland will not fail to attract the eye ; bnf the Australian opals have not yet been found applicable to the pop- poaea of the jeweller. The fire opal is brought from Mexico, and tJH oommon opal, abundant in Hungary, is found also in ForJie, Iceland/ the Gianrs Causeway, and tho Hebrides. Syallle, or Muller'$ ffloM, is a colourless transparent opal ; while meidlite is on opaque browA opaline concretion occurring in the tertiary strata of Menil-mootant,

In this case are many examples, from Trinidad and other placeai of the curious changes effected iu wood by siiioiflcation i and in tha first gallery will be foupd some larger specimens. The change has been so gradual that the woody stmcture ia perfectly retained, and In the section of the palm trees in the gallery the arrangement of the cellnlar tissue ia preserved.

Case E, — Alvmisl ; AnnTBBOua Silicates.

The 'coarser forms of alumina, or oxide of aluminium, havinj

been already described under the names of emery (p. 42) arw_

eoriiJidwH, (p. 103), it remains to notice, in this place, only thoae

fine transparent varieties which, from their eicessivo hardneas anil

beauty of colour, are highly valued by the Jewells. These pui*

I (brma of alumina are idmoBt exelosively brought from the eaald

. Chiefly from Ceylon, Pegu, and Ava, where they occur embeddfflt

'1 sands and gravela. The bright red varieties conatitate th

ariental ruby, so called to [distinguish it from the totally diatinot

Eand much less valuable mineral, spinel, which is also Imowo lit commerce ae "ruby" SappMre is a name applied to the bias transparent crystals of corundum; Pliny's name of asteria beil retained for the " atar sapphires," or those varieties which exhi a star of light when cut with a convex face. Other brightly coloured corundums paea in commerce Ba "oriental" gems the green as oriental emerald, the yellow aa (ojwu, and the purple aa amelhytt ,- but it must be remembered that theae oriental stonM diflfer easentially, both in chemical composition and in physical r charactera — colour only excepted — from the gems whoae names they bear. The preparation and properties of metallic aluminium, the taee ofalamma, have been notic at p. 75. large seriea of anhydrouB BilicaleB,OQcajmgttiaremainderof otB oaae and Bereral o£ the following 08aeB,eiii&twBia.a7-QaaKCii!s

Hoese-Shoe Case.

of considerable tbIuo as ureoinaa stonea. Tho double silicate of the ' aHlied earths tklnmina and glticina is known in its coarser varieties ' as Seryl, of which enormons aix-siiled crystals are Ibund in the I Thiited States. The fine transparent green varieties ore distin- gniithed as Emerald, while those of paler tint pass auder the name of Aquamarine. The rich colour of the cmersild is due either to I oxide of ohromium, or to an organic colouring matter. The gem is J dlieflj obtained from the Mines of Muzo in New Granada, where it I ooenrB crystallized in a black oarbonaoeoas iimestone. Spec

a the matrix, accompnuied by

chemical oomposition is the brittleness of which renders it Tha etirth glacina also o

I will be found showing its

I Some fossila from the limestone.

Closely related to tho emerald ii I mineral called JSuelase, the orcesaivi nsolesB for pTuposea of ornament.

combined with alumina in the Chryeoberyl or Ctjmophan : certain varieties of this mineral, when cut en eahoekon, exhibit a pecnliw opalescence, whence the name orientnl eai'a-eye.

Among the small number of minerals which contain tirconia, the "most important is the silicate called Zircon. The transparent coloured zircons are used as gems ; the rich red varietiee being aistinguished as Hi/acinth or Jaci/nth.tmd the leis brightly coloured 't Jargoon. The hyacinth ooeurs in the form of rolled orystnlB, ohieflyin Ceylon and central Praof ; whilst the eoaie dull-colonred Zireonife forma a conatitaent of the peculiar zireon-syenite of Norway, and is also found in the miaaoite of tbe Urals.

Pew minerals present greater complexity and variability of com- position than the Toiirmalina. Its crystals are remarkaile for a Want of symmetry between tho oppoaite ends, and for aeqniring electric properties on espoaure to heat. Tha black tourmaline is commonly known ae Schorl, and the pink as BubelUie : a striking variation of tint in tho same crystal ia well seen in the parti -iT,lonred toormalinea from Elba.

CisE 8.— AiJHTDsoiJS Silicates — cojUinucd.

Many of the silicatae exhibited in this case are, like those in the last section, employed for nurpoaos of ornament. The group oSQaiyieh embraces a considerable number of m.iiioralB which are eaaentially double silicates, the varieliea depending on the character of tbe bosea. The deep-ooloored Jimaiicime or preclnut ffartet,' s. silicate of uluniina and protoxide of iron, ig frequently cut en caiochan, when it is known as CarbimeU ; and the Euatiilc or ci'ji- aamon italic is also used as a gem, being often mistaken for hya< cinth. SsBonite is a silicate of alumina and lime, thus having a composition similar to that of tiie Siberian Qtoesularia or gootabei-ry garnet. Another Busaian garnet is the nwiavivjic, a mineral having a briIit cinerald-greon colour, and containing the silicates of lime, alumina, and sesquioxide of chromium. The species Idocrase or vesTivian has a composition identical with that of certain garnets, but CTystallizes in forms totally distinct.

In the Topea, to which we next pass, a silicate of alumina is asso- ciated with a silico-flnoride of aluminium. The topaz is found in the ibrm of rolled pebbles, and in granitic rocks commonly associated with quartz, and not unfrequently with tin ore. TIio yellow and the white topazes, chiefly from Brazil, form valuable gems and ia many cases a pinkish tint is developed by exposure to beat. The topaz of the ancients appears to have been the stoue which we now csif (rsoHU; this is a silicate of magnesva ot & to& eea.'iiJi.isWi

136 THE PRrSCIFAl FLOOR.

known also as Feridoi, the name OUoine being applied to the transparent varietiea, commonly found in meteorites, and in basalt and other trap rocks. Eiamplea of theae varietiea are exhibited.

The Sj>iriel, or spinelle, of which the bright rod varieties a™ HBflct as a gem nnder the name of e2miel nibij, is not a eilicate, bnt is & cotnpoiand of alnmina and magnesia, the latter being freiaentlj replaced to a oonBidcrable extent by protoxide of iron.

Case T. — Anhydhotts SiLICATEa — cant'iniied. The minerala in this caae, althoagh leaa attractive than those the preceding eeotions, aro ueverthelesB of the highest interest j-oct-GOnstitnentB. At the head of the series standB the family of Feisparg, including a number of apeciee, of which the best known is the potaeh-felapar, Ortiwdaae. The transparent orthoclaae called Adv,laria is occasionally used for purposes of ornament under the name of Moon stone. MicrocUne and AiiHtf.mi etoiis are two other vBrieties of orthoclase, the former noticeable for its beantifal opal- escence, and the latter for its fine appie-green colour. An attrac- tive specimen of Amazon stone, crystallized in cavities of a granitic rook, stands under a glass shade on an adjacent table-case. Obsidiwa or volcaiiic glass, is a vitreous form of felspathic lava, frequently pro- duced by fusion of impure orthoclase. It is employed by many savage races for making cutting instruments, and was largely iiaed in this way by the ancient Mexicans. The curious filamentous material from the Sandwich Islands, known as I'tU's hair is a capillary lava, similar to the hair-like forms of slag occasionally

Sroduced in the blast-furnace by the slag being caught by the blast om the twyer, and blown out into threads like spun glass. F6U'a hair should be oompared with specimens of slag in case No. 4, p. 56. AlUte and Oligoclase are closely-related Eoda-felspars, the soda being usually accompanied by lime in the latter speoies. The Norwegian Svn elone or Avanturine-felspiiT is a variety of oligoclase, notable for enclosing certain minute crystals from which light is brilliantly reflected. Ortboclase-felspar, commonly associated with either oligo- clase or albite, forms an important constituent of granitic rocks (p. 24), whilst the soda-and-lime felspar Lahradorite. is characteristic of the group of basalts (p. 47), Attention need scarcely be direoted to the beautiful play of colour exhibited by the polished aJabs of labradorite.

Case S.Anhtdeous Silicates — conlinwd.

In this case the large and important series of anhydrous silicates is continued, and several interesting sjiecies are represented.

The well-known, lapis laBidi appears to be a silicate of soda, lime, and alumina, with, probably, a sulphide of iron and sodium. It is found on the banks of the Indus in a crystalline limestone ; and in limestone and granite it occurs in Persia, China, and Siberia. The richer varieties of lapis lazuli are employed in the manufacture of ornamental articles; and when subjected to careful powdering and washing, to free it from all foreign udmixtitres, it forms the uttro- marvae of the artist, which is so celebrated for its beauty and per- manence. The rarity of the mineral, and the cost of preparation, render the true ultramarine of a very high price, HI. 5. per ounce.

An artificial ultramarine is prepared by mixing clay, carbonate of

soda, and sulphur, and carefnliy beating the miiture ; the result is

s rerj- ft'ne blue colour, which is said to bft equally permanent with

natural lapis luzul'i, and -wliich caii Aae wAd aX. Sb, ft\e, -mtiA.,

R0R9E-Sh0E Case. 137

Kiamplfs of tbe genuine aad of the artificial altr&marmc stand side by aide.

The members of the Mica I'amily, of which eeveraj are hero ex- hibited, differ from one another in crjBtalline form, optical choracters, and chemical cnmpoaition. They arc impurtant as coDHtitnenta of granite, mi(;a elate, and other rocks. A portion of an nnuaaally large cryafcal of Canadian mica will be fonnd in the lower part of Case No. 30.

Jade or nephrile ie wejl known as a mineral which, in spite of itB hardness, is largely worked into imnges and ornnmentH of varions Kndfi by the Chinese ; it is also found in Anstrolis, New Zealimd, and some parte of North-west America. It ahonld be mentioned, bowCTcr, that at least two distinct mineralB have until recently been confounded under the general name of jade. Tbe trae jade is esBBntially a silicate of lims and magnesia, wbile the Rpecics jadeile, often mistaken for it, is a silicate of atnmina nnd soda. The name nephrite ia derived from yppis (iihros), kidn — it being used for diseasea of that organ by Bome people. Some fine Chineae earrings in jade and jadeite are in Case 63.

Several beautiful crystallized minerals Buch as E'jjiJofs are fairly represented in tbis case, but aa they have no general interest attaching to tbem, ony notice would be out of place here.

Case TJ. — Ashtdbotjs Sdjcates — ermtimied.

Here the visiter will find a very inatruotive ;roup of silicates embracing the different varietica of the closely-allied species AitgUe HoTWilende. It ia notable that the augitic minerals are charac- teristic of lavas, basalts, and other igneous rocks, which contain the more basic felspars ; whilst the hornblenUea occur in diorite, syenite, &c., UBUally in company with highly silicated felspars and often with free quartz. There are esceptiona however to such associations. The fibroQs forms of hornblende and similar minerals are known as Aalostoa (inconsjimabU), from their power of reeisting the action of intense beat ; hence asbestos cloth, woven from the delicate threads, may be espoaed to fire without being consumed. The delicate fibres are diatiniahed as minmlai'n , while the massive forma restdting from the interlacing of these fibres arc called, according to their testnre, tnowiiiiin leather, rock cork, c.

At this point we pass from the anhydrous to the hydrous silicates, oommencing with the hydrous silico-borate of lime, called DatholUe, a epeciea, however, of only mineralogical interest. Prom this we turn to the well-known Mea-echaiurt {sea froth), or -EcHina de mar, eo called in allusion to its lightness aud white colour. This ia a hydrous silicate of magnesia, found in Asia Minor, Turkey, Greece, Morocco, Spain, and Moravia.

Case V. — HvDKons Silicates.

This case is entirely occupied with the two olosely-related species ierpentitie and steatite, both hydrous silicates of magnesia.

Enough has already been said of serpentine as a rock, when desoribing the fine objects in the Hail (p. 29). Other essmploa of tbis ornamental stone are exhibited in the case before ns, where also will be foaud specimens ofiioble or precioTis serjieiitina, a variety of oil-green colour, slightly translucent-, c1vr|jsoUU OTii -jftmiWiis,

138 The Prihoipal Flooh.

the ono ft fibrous and the other a colonmar Tariety ; of irutrmoliU aad anti<!orite, the former a foliated, and tho latter a lamellar form of serpen tmc.

Steatite frequently oeoars in nafiociation with aerpeotine, aa in the Lizard Dietriot in Western Cornwall, where the ophitie rooks are ' travereed hy yeins of steatite. The mineral is remarkably unctaoctfi to the touch, and ia hence popularly termed goojwtoifl ; advantage ia taken of this property in using powdered steatite for causing new gloTea and boots to slip on readily; the vftriely employed for this purpoae is generally known aa French dmVc. Soapetone ia carred into pipes by certain South African tribes, and ia also used by the Chinese for carving figures. It reaiats the action of heat and has been tamed into gas bumera and similar objects ; at one time it was used in the manufactnre of porcelain at the Worcester Works. When lamellar it is generally known as Talc, a name frequently applied improperly to mica ; the two are however easily diatin- guished, the talc being ilexihle but not elastic, whilst the mica enjoys great elasticity.

Cask W. — Hydeobs Silicates — eontiiiJied, It is the mineralogicsl student rather tLan the general visitor who will be interested in the minerals in this coac. The Chlorites form a group of closely-allied minerals, comprising severai species difl'ering one from another in cry stall ographic and optical chamctera, The Jjemniwa earth, foimerly valued in medicine, was esteemed sacred by the ancient GToeks, being mixed with goats' blood, and made into cakes, which were then stamped by the priests, whence it vras called esaled or saered ea/rih. From the use of the AgalmaioUie by the Chinese for carving figures it has received the names of figwre stone and pagodite. Several distinct subatancea, however, are nsed for these tjhinose carvings. The white powder labelled Kmilmite exhibits under tho microscope beautiful little six-aided plates, and represents in a state of purity the hydrous silicate of alumina which in ita impm-e forms constitutes our common kaolin or ddna-day (sea p. 141).

Case X, — Etdhoits Sojcatbs— coniiiiiMf?. The nediiiie mmeraZB occupying this and the following case are related by several characters in common. They are essentially bydrouB ailicatea of alumina with an alkali or an alkaline earth ; and are naually found in the cavities of amygdaloidal -rooka, a few however occnrriag also in metalliferoiia veins. Beautiful in their crystallino forms, and interesting in their chemical composition and mode of occurrence, the zeolites aie highly attractive to the mineralo- gist, but as they receive no practical applications, any detailed notice in this place seems unnecessary. The principal species represented in this caae are PrekiiiU, a hydrous silicate of alnmina and lime, of which some fine examples are exhibited from the igneous rocks of the Dumbarton Hills; awdcime, a hydrous silicate of alumina and soda, often containing also potash and lime ; and aophylUte, s. mineral differing from the true aeolitea in liat it contains no alomiha, being in fact a hydrous silicate of lime and potash. Especially noteworthy are the fine Indian crystals of apophyllitfl litought to light during the ontting of the railway tuiinele on tho etapeadous inalineB ascending the Shore and Thul Ghauts (p. 104).

Hohsk-Shoe Cabs

Case Y. — HDUOi'i Silicates— ?o[HiiMrf. Here the visitor irill find a large number of beftntlfnl seolitio minerals, which it is tmncoesBary to deaoribe in detail. The difierenceB in chemical compoeition are sufficiently explained by the accompanying labels. Among the more notowortliy Bpeoics atten- tion may be called to natroUte in beantifuJ needle-like MTBtals ; chahruite, in fine rbombohedral forms almost lilce onbes; hamuitfyme, in milk-white twin-cry atals, as thongh two individaals were crosBing each other ; and itttoite in crystala with brood cleavage planes ex- hibiting a pearly Instre. The salient (araoters of many of these species are sninoiently explained by their popniar names, anch as foliated zeolite, needle-stone, radiated 20oht, efi'erreBcing zeolite,

Ca5e Z, — PnosPHiTEs or Atcfsnoi, Ac.

A few minerals containing phosphate of alumina are grouped together in this, the last division of the horse-ehoe case. Wavelliie isa mineral occurring chiefly in small globular concretions, whicii when broken present a beautifully radiated structure; the species takes its name from Dr. Wavell, who discovered it at BnmBtaple in Devon. CliUdrsnite is a phosphate of alumina, iron, &o. found in a few localities only in Devon and Cornwall, and named alW the late llr. Children, of the British Mnaenm. Passing over a few oUier TMB species', the visitor will fao attracted by the spechnena of JW- quoiB. This mineral is a hydrous phosphate of alumina, containing copper i and when of fine colonr is valued as an ornamental stone. The finest specimens are brought from Persia, others are supposed to come from Thibet ; and some years ago discoveries were made in Arabia Potriea, From all these localities, especially from the last- named, specimens are exhibited. The mode of ocourrence, and the tnrquoise separated from the matrix, are shown. Tho Arabian specimens were mostly presented by Major Macdonald, who thaa deacribes the locality in which he fonnd them; — "In the year 1849, during ray travels m Arabia in search of antiquities, I was led to examine a very lofty range of mountains composed of iron sand- stone, many days' jonmey in the desert; and whilst descending a mountain 6,000 feet high, by a deep and precipitate gorge, which in the winter time served to carry olT the water. I fonnda bed of gravel, where I perceived a great many small blue objects mired with the other stones ; on collecting them I found they were tur- quoises of the finest colour and quality. On continuing my ra- aearcbes thronh the entire range of mountains, I discovered many valuable deposits of the same stones, some quite pare, like pelibles, and others in the matrix. Sometimes they are found in nodnles varying in size froni a pin's head to a hazel nut i and when ia this formation they are usually of the finest quality and colour. Another formation is, where they appear in veins. They also occur in a soft yellow sandstone, enoloeed in the centre, and of snrpaasing brilliancy."

In addition to the tme oi-ittal turguoiao described above, the jeweller avails himself of a substance somewhat similar in geneml appearance, but known as occidimUil twrquoUe. This is the odonMite of mineralogists, a substance which appeals to be nothing more Aian foesily ivory, bone, or tooth, coloured with phosphate of iron.

140 The Principal Floor.

CERAMIC AKD VrrRBOUS SERIES. On the Eadem and Western sides of Stairs. PgTTFHT AND FoECELAis. Waii-oBBBB Oil the W. and E. sidea of fhs eii(6<i;/me)tto, and adjacent pndeilal-aaeeg ; also table-cases in lower gallery.

A large collection illuatrating tte varioua branches of ceramic mid vitreouB laannraotnrea, especially rich in illustration a of the history of British Pottery, is ejihibited at the eontiiQra or Jermyn. Street end of the Princip&l Floor, where it is entirely separated From the mineraiogical and metallurgical collections. The ceramic and vitreoos collection is arranged in a seriea of forty-four wall-caees distinguished hy Boman nvimcrels, in glass-cases reetins on the cornice of the balustrade on each side of the staircase leading from the Hall, and in eeveral pedestal-cases in the neighbouring area. The numbers and letters correspond with those on the objects exhibited, and with the references in the catalogue of pottery, of which a third edition has recently been published (1876).

It will be desirable to commence the description of the ceramic series by describing the raw materials used m the manufacture. Examples of these materials will be found in the lower com.part- ment of Pedestal-caBO No. 57 ; and a valuable series of British clays, collected and presented by Creorge , Esq., is exhibited in the lower divisions of the several pedestal- cases occupying the two embaymentfl.

Clai, the plastic material upon which all ceramic manufacture dejtends, is essentially a hydrous silicate of alumina, its peonluir fictile properties being due to the presence of the combined wftter The prosimate constituents of pure clay Eire here represented hy the roc* erystal (A. 1), a pure form of si'Ji'ca,- and by the emery (A. 2), an impure variety of alumina. The eilioate of alumina formed by the nnion of these two componnds — silica and alumina — exists in com- bination with certain alkaline silicates in all the members of the felspar group ; and it is by the decomposition of these felspathic minerals that our china clays are produced. In the common species of felspar called orthoclase (A. 3), a specimen of which is here placed as a representative of the famtlyj the silicate of alumina is asso- ciated with a silicate of potash. When the felspar suffers decom- position the greater part of the alkaline silicate is removed in s soluble form, whilst the silicate of alumina, being left behind in a hydrated condition, forms the clay which we employ in our fictile mannfactures. Specimens are exhibited of onr principal pottery clays, of which the following are the more important ; —

Bove/y Clay (A. 15). This is obtained from Bovey Heathfield, Devonahire, and is derived from the decomposition of the felspars of the great granite ranges of Dartmoor ; 59,789 tons were sent firom the port of Teignmouth in 1874. The mode of raising it is extremely simple,— the gravel head is removed, and a large i-ectan- gnlar pit is sunk, which is supported by wood. The workmen cut out the clay in cubical lumps weighing about 30 lbs. each, and fling them from stage to stage by means of a pointed staff; it is then carried to the clay cellars, and when properly dried sent to the potters.

Pooh Clay (A. 16), so called from being shipped at Poole, occurs in the Lower Bagshot beds of Dorsetshire, and contains numerous regetabJe remains, principally parts of such plants as belong to n

I euE-tropical climate, like that of Africa 8,\oDg tbe aVotda n't ftia

FOTTEKT AKU VOKUtLiar. 141

JTediterranean Sea, ExamiileB of these plants will be foaud in tho caeee at the aoutb end of tlie appor gallery, Nos. 6S and 66. 63,705 tons of this clay were exported in 1874 from the port of Poola.

CiMa Clay, Kudtm. or CornUU Clay (A. 5 to A. 14).— About 1775 William Cookwtirthy, of Plymooth, discovered that the olavs of iegonning hill, in the parish of Breage, neur Helstoue, in Corn- naJl, -were of the same character as epecimens of Kaolin wbicU ha had Been, brought from Virmnia. Aaaociating hiroseif in this dis- oovery with Laid. Camelfard, Cookworthy worked the China clay oa hia Lordship's propertrf in 8t. Stephen's, near St. AaHtell. He established tho poroelaiu manufactory at Plymouth, which was eventually removed to Bristol, and thus laid the foundations of the great advance in porcelain manufacture in this countrv.

Kaolin or China clay is prepared chiefly in tho ceighbourhood of St. Anstell,and St. Stephens, at St. Day,Tgwednackand Trogoning Hill, in Cornwall; and at Lee Moor, and at Meavy in Devonshire. The decomposed granite rock is broken out, and ia commonly espoaed on an inclined plane to the action of a fall of water, which waahes it down to a trench, whence it is conducted to catch pits. The qonrtK, schorl, mica, and other minerals present are chiefly retained in the first pit, and aa tho water charged with the clay flows onward it deposits the grosser particles, and eTentually tho pure and fine olay is deposited in tanks prepared to receive it. These tanks are about 9 or 12 inches deep, and when filled with clay tho Wfitor is turned in another direc- tion, and the mass allowed to eonaolidnte. The clay ia then run into a roofed building, beneath the floor of which hot aircirculates freely. Thus the clay is dried perfectly. It ia then cut into oblorg lumps and having been scraped to remove dust from the outside, it ia sent to the potteries. In Devonshire and Cornwall artificial heat is applied, but the clay was formerly dried at the natni-sl temperature.

In 14, 150,500 tons of China clay were exported from Cornwall and 33,S09 tons from Devonshire.

The China clay is now nsed extensively in our paper mannfoc- tories, it is finding a new application in the preporation of the figured papei's for walls, and it is u.sed estenaively in all our bleach- ing establishments.

CiiOfA SiOME (A. 22 to A, 25). — This is generally regarded as the product of tho granite rock which furnishes the Kaolin, but in a leas advanced state of decomposition — the felapur still retaining much of its silicate of potash or aoda, associated with tho quartz and scales of a greeniah-yellow talcosa substance. Of China stone there were sent to the jmttei-ies from Cornwall in 1874, 42,500 tons.

Flints, ae obtained from the chalk districts (A. 26), and in a pre- pared state, calcined, crushed, and ground {A. 27 to A, 29). It is said that the introduction, of flints into the manufacture of pottery was by Mr. Astbury, a Staffordshire potter, who was led to make experLments on their use from the following circumstance ; — -

In 1720, riding to London on business, as was then a common practice, he found, on reaching Dunstable, that his horse's eyes were disorded: he consulted the ostler at the inn, who placed a piece of flint into the fire, heated it to redness, and after throwing it into water, reduced it to powder, a little of which powder ho blew into the horse's oyes. Aatbnry, observing the white character of tho flints, aent some to Shelton, where he had burnt and

Ewdered, and mixing the powder with pipe-clay, he first xcaalied ware with it, but ultimately introduced the flinta into the body. Ia a table-caae in the gallery im.me4iate\"j iiiuaQ "Cii&TSi -ca b-ie*l

143 Ibb Frikcipal Twob.

B&mples of raw materiak uaod ia some of the continental poroelain works. The materiala in hoxea are those employed at the Frenoh por- celain manufactory' of S&rros ; and those in bottles are examplee of the materials used in the porcelain works at Berlin-

Potteey Mancfactuee. — Ah space will not allow of a detailed description of the variona processes of pottery manufacture, the following outline must suffice. The prepared materinls, reduced to a finely divided state and suspended m watr, are mixed in doe pro- portions; and the fluid miiture, or ' slip,' brought to a pasty consis- tenoo by evaporation in the ' slip kiln.' The paste thus prepared is shaped, either by moulding, or more usaally by ' throwing ' on tiie potter's wbeel ; and the form, if necessary, is afterwards perfected by turning in the lathe. When handles or other appendage are to be added, they are attaclied at this stage by m.eang of slip. Alter slowly drying, the ware is packed in fire-clay boxes, called ' eeggara,' and baked or ' fired ' by exposure in the ' biscnit kiln.' The porous baked ware, known in. this state as ' biscuit,' is then ornamented by painting or printing [ and having been dipped into the glaae suspended in water, is finally baked in the ' gloss kiln,' where by the vitrifica- tion of tbe glaze the pottery becomes covered with a thin coating of transparent and impermeable glass The various stages in the manu- facture are illnstrated by apecimena in the lower compartment of Pedestal -case, No. 57,

The arborescent patterns upon (B. 10 to B. 32) are produced by having first, an evenly' -spread coating of ' dip ' over the ware, and then dropping upon it aJiother ' dip ' compound, having a greater density than the first : by holding the piece bo that the heavier colour can descend am.id the moist, first-spread ' dip,' it disaeminates itaparticles in an arboreaoent manner.

Several designs will be found in this case illustrating the transfer of engravings to pottery, a process now constantly employed in its ornamentation. Being recently printed on a thin paper, the design is applied to the surface of the absorptive ware, and being carefully rubbed close, the article ia dipped into water, the wetted paper is then removed rubbing, and the desi is fixed on the absor- bent clay, which is then glazed and fired in the ordinary way. Aji earthenware slab (Q. 524, Wall-case XSXVIl., E. side), in the form of a framed picture, shows a transfer in colours of Mulready's "Village Schoolmaster."

It is ever interesting to trace the progress of any special industry bearing upon an important branch of modem manufacture. The Museum of Practical Geology was intended to show bow mineral products have been rendered useful; and as our ceramic manu- factures form an important feature, some history of their progress was deemed deairable. To read the series aright, it will be necessary to examine this art-manufacture io some of the most ancient of the preserved examples.

AsBVsiAB AND Babylonian BfiicKs. Case 63. (C. 23 to C. 28.) — The gloMS have been examined in this establiBhment, and they are found to be silicates of soda, or soda glass, coloured opaque white wi oxide of tia (Ftiitiy powilm-), yellow with antimoniate of lead (Jfopfe* yelloin;), and blue with silicate of copper. The blue colour from copper wag previously known, but the use of lead, antimony, and tin, in glazes or enamels, has to be carried many centuries farther back than has been usually supposed.

.-j.vSBPPiCHHAxFiGUEES, Ac. Oaae 63. (0. Ito 0.22.)— Many oftbeae Sgares are of pottery, or ratter ol a. Srit ioxBLei <il stajaa

POrtERT IND taUCBLAIS. liS

of sand cemented by 'some vitreonB material ; bat Bome of tho Agnres end Bcarabiei are fannd to be oorvL-d out of a Bteatitio minerol. Thesw have been dipped in a, ouprifsToiiB glaze and theu fired, the Bteatite reeiating the heat required to fuse the glaze.

TliOHe examplee of the timoa of the Pharaohs serve to show the early condition of the potter's art i from thom wo learn that tho Egyptians had found that ateatitic minerals might be advantageously empkijed in tha place of the ceramic bodies.

Ibbian Ekamel. Case S3. (C. 29.)— In this specimen tho frit* arc enamelled with different-coloured glasses and enamel frits, then cnt 30 as to form a, deeign in moaaio, when embedded on a wall of cAwumi or plaster, These oniunellcd frita have been naed in India from the I3th century. This example ia from the tombs of the Eootnb dynasty, Golconda.

Ajjcibnt GaEEK iHD Btrdscan Poteert. Case 67. (C. 30 to 0. 51) — This case ie placed on the bridge wbich apana the staircase leading from the Hall to tho Principal Floor. In the Greek vases may be studied , in addition to the eharacter of the clay bodies, the style of ornamentation, the glaaes, and especially the forms, many of which ace very beautiftil. In nearly all these vaaaes the body is of a reddish clay, and the whit and other oolonrs employed in the ornn- ment are aoloured clays or enijobcs, painted on the vaseS after sketches of the designs were eseonted on them.

EojiiN PoriERY foniul ia Britain. Caee frl. (E. 1 to E. 196.)— The Koman pottery is of three doscriptions. Tha Uvekureh ware, which ia of a fine and hard texture and of a hlne-black colour, was bakedin " smotherkilna," where it was acted on by the smoke of vege- table BUbstancea. The forms are very varied and the patterns much ajveraified. In the creeks of the TTpchurch marrshes at the mouth of the Medwaymay he detected, at a depth of about three feet from the present surface soil, a stratum, often a foot thick, of broken pottery. This deposit of pottery has been traced at intervals through an extent of eix or seven miles in length and two or three in breadth. Mr. Wright says, "There can indeed be no doubt that tho Upohuroh marshes furnished a great portion of the commoner pottery used in Eoman Britain." A fine coDectiuo of this Upoburch potteir is arranged in the lower compartments of tha adjacent Oaaos 68 and 69.

The Cattor or Dm-dbrlvicm jiotlery was of a superior qnaliiy, and adorned with more elegance than that of the Upohurch. marshes. Mr. Artis has explained, in his D'arobrivcE of Anioninwi, the mode of mannfactore. The third variety is the Samiaa Ware, so called from being similar to the earthenware made from the red clay of Samoa. Of this a very large quantity has been fonnd in England : whether the Samian ware was ever mannfaetured in Britain Em given rise to rauch discussion, That it must have been of muchvalueisprovedby finding howls and paterro of this rod ware, which have been broken by their ' Boman posaeseora, and auhsBquetitly mended by means of lead rivets, in the same manner as earthenware and china are &t>w mendedbymotallicwirea or bands; several examples of such repau-ed pieces are in the collection. The common Samian ware of Britain ts of delicate textnre and of a fine red colour. Many of the speci- mens exhibited were discovered during the progress of im.prove- menta in the city of London: Cannon Street, Foster Lane, Queen Street, and Lad Lane have yielded a large number of these

ms FKINCIPAL FLDOB.

BoMAS Pn tTPHu ' KiiiBS AND Tools disoovered in Sritaiii. Caae 64. (E. 75 and B. 76.)— The kilns of v/hich these are models were found tA Normanton Field, Castor, near Peterborongh. A groat number of BHch kilns were diacovered by Mr. Artis, and the following quo- tation from ha ioac p on o ' them shows the extent to which earthenware manofac ure was carried on in this country by the Bomana.

" I have now trac d these potteries to an extent of itpinards of 2 miTes. They a p no pn y confined to the gravel beds on. th hanks of the Nen and bn ary atreama the clay iiaed at Bom_

of them appears o have b en olleeted at some little distance (Voin the works. The kilns are all constructed on the same principle. S circular hole was dog, from three to four feet deep and foor ii diameter, and walled round to the height of two feet. A farnBoa, one third of tlie diameter of the kiln in length, communicated with the Bide. In the centre of the circle so formed was an oyal pedestal the height c>f the sidea, with the end pointing to the furnaoa mouth; upon this jiedeatal and eide wall the floor of the kiln rests ; it ia formed of perforated angular bricks meeting at one point in tiie centre. The ftu'nace ia arched with bricks moulded for the purpose. The side of the kiln ia constructed with curved bricks set edgeways in a thick slip (or liquid) of the same material to the h ' ' ' " " feet."

The bone and ivory tools, and the bronze iastrumantH — all fonnct at Castor— were used, there can be but little doubt, for producing pattema on the clays. A large fragment of a cake of glass or fn'' (B, 86) waa also found in this pottery. Thia has been analyzed i . the establiahment, and found to be a silicate of aoda and lime, similar indeed to much of the Boman glasa.

BoiIA>" Pottery, from ihe Rhitie. Case 64. — Aa eiamplea, im

taut for comparison with the pottery fonnd in Eoman Britain, tl

are of much uiterest. They were manufactured on the banks of the Chino, where, in several localities, Boman pottery kilns have been found. It ia not improbable that the red lustrous ware of Rhenish manufactoi'e waa introduced into Britain ; it ia certain that large quaatities of pottery of a precisely similar character have been diacoTered in thia country.

Mkdisval POTTBEV. Case 63. — Under this general headare grouped many articles diaaimilar in character, and widely separated in date. These examplea were collected for the purpose of exhibiting the pro- gress of glazing. The tilea {C. 52 to C. 69) which have been found in Taiioua parts of Bngland, are coated with a lead glaze ; whilst those of the Moorish pa&ce of the Alhambra and the Alcazar ahow the uae of a stanniferous enamel. Mooriah tiles were probably introduced into Italy in 111-5, when Majorca waa taken by the Pisans, and they were for along period employed for ornamental purposes in charchea. Luca della Eobbia, celebrated for his terra cotta figures and baa- reliefa covered with a stanniferous glaise, also made enamelled tilea which he introduced into the church at Piaa about 1415-20.

MiJOLio* oa BAMiEtLB Wam. Case 63. (C. 90 to C. 100.)— The Moorish ware was first introduced into Majorca, and from thence it spread over Italy, under the name derived from thia island, " Mnjo- lita." It has been called Raffaelle inare from the fact that aomo c' the decoration has been copied from the deaigna of that painter , mMoj of them are by artists of Lis acbool, but it ia believed that Saffkelh himself never painted on thia ware, although a letter is attributed to him in which he iat'orma the T)ac\ioaa oS Tifovoo Vo.'s,

POTTEBT Asm POnCELADT. 145

the deaigng are ready which she had desired for porceinin for her BideboBTO. This ware waainost extHnaively manufactured from 1540 to 1560. It was especially patroniKed by the Dokes of Urbitio, whose arms are on the rim of one of the BpeoimenB. The maanfac- tore greatly declined after 1574. The chief point to be observed in the Majolica is, that the body or paste was first Bred, and then by iromerBion covered by a compoaition of oiide of lead, oside of tin, and white earth, the proportion of tin being increased as the enamel WS8 required to be white and hard.

Palissy Wabb. Case 63. — Palisay of Saintes wan in every respect an extraordinary man. He was bom in 1509, at Chapelle Biron, a poor hamlet near the Hmall town of Biron in Perigord, but politically situated in the diocese of Agon. He was educated as a glasa painter. He write a of himself in L'Art tie Terre, " 1 for a long timo practised glass painting until I was assured tbat I conid earn bread by labour on earth." Some accidental circumstance directed his attention to pottery, and he was seized with an earnest desire to discover an enamm for a clay body which would equal anything whioll had been produced. Not knowing what had been done by others, he, with the utmost enthusiasm, proceeded in his inquiry. Beriiard Palissy, Breaking of his experiments, says, " Having blundered several times at great exjrense, and through much labour, I was every day pounding and grinding new materials and constructing- new mmaoes, which cost mach money, and oonsnmed my wood and my time." Again, he says, " I fooled away several years with sorrow and sighs, lessening the bread of my children, and weighed down by domestic cares." Eventually success crowned his endeavours, and the works of Palissy the Potter became famous. None of the genuine ware of Paliasy is at present in the collection, but the copy, C. 101, sufficiently shows the chanuiter of the ware, in which its author, — a devout lover of nature, — executed in relief, reptiles, fish, plants, and even the fossil shells of the environs of Paris, with the most marked attention to the minutest peculiarities.

Delpt Dish. (C. 103.) Case 63. ; also specimens in wall-cases on western side, bottom shelves. The. manufacture of the famous Delft ware was established about the commencement of the seventeenth centnry, and for a long period was much esteemed in this country. The composition of t'oar of the moat important of the wares just named proves to be very similar ; they all agree too in being coated with glazes containing tin. Brongniart gives the result of his analyses as follows : —

—

a.

ill!

Oiiiioof'carbonio Iron. |Ada.4D.

Lnca rlclla Robbia

1.

nrp

a2-40

Majolica

]7

1'17

3-75 9-46

ie-01

PaliHSy

67' 50

an

ol

2-05 —

The marked difference between the Palisay and the other wares ia the increased quantity of silica, and the exceedingly small proportion of lime.

CanrasE PoncEEAm. Case 63. (C. 104 to C. WS:— Ta-je '-a.-At tratioos serve to shoiv us in what respecta vje "je ft\S\. "yi Va."Evi.

40332. S,

146 THE PBraon-AL Ftoe*.

orities preaented in 'their works have not yet been HttaoeBafaUy, imitiited iu Europe ; tbe coloara giveu to thejar {C. 107) furnish one example of thiai here a felspar glaze is emplgyed, and the blna Eilioate of coppor and of an alkali has been partially reduced, eo thab a portion romaina of a purple colour, from tho diaaemiaation of aub- oxidoofcopper amid the ailicatea. Cracldi.tChina {C.llQ and C. Ill) is produced by covering the white porcelain body with a thick opftquo enamel which, after firing, "crazBB" or splits in vatioua

According to M. Stanislas Julien the manufacture of porcelain was commenced in the country of Sin-]i'ing sometime between B.C. 165 and A,D. 87. It is now largely mannfactnred at several locaHtiesi Davis informs us that there ia a large monnfaetory at King-te-cbin,' and another at Ohau-Mng-foo, west of Canton ; it is aaid that at the former place there are nearly 3,000 kilns.

Tho Chinese potters employ Kaolin ( Kciou-Un—loftij rldqe and pe-hm-iae. It is generflify said that the Kaolin ia similar to th* Comiah China clay, and the pe-tnn-tse, in all probability, to the China atone of the same district. Jliia- (slippery stone), steatite! 01' soapstone is also used by tho Chinese. Laurent and Malagnti

—

SiUca.

AluminB. 1 Potaah.

hmo.

ProtoiidB

Body of a white

yaae Body of a greenish

20-7 ! 6-Ij

0-G

01

Trace.

The Portuguese introduced Chinese porcelain into Europe about tho year 1520, Imt the earliest mention of China ware in England iA said to he in 1586.

EuEOFEAS POKCELiK, — The introduction of Chinese porcelain infer* Europe produced a Strong desire to imitate it, and it is said that a

to the oriental vias made until Bottoher'a discoveriea in the 18th. century.

Bottcher fii'st worked at Dresden with a brown clay, fonnd near Meissen, and produced a red ware ; and in 1709 he made whita porcelain. Augustus II., Elector of Saxony and King of Poland,

director in 1710. Ia 1715 he aacceeded in making fine and oxcellent poreeliiin. This manufactory has continued to the present day, pro- ducing that saparior porcelain commonly known as Dresden Chiii&

Sohnorr, an ii-onmaater, riding near Aue, observed that a soft whit* earth adhered to his horse's feet; consideringthat this earth might used aa a substitute for wheat-flour as hair powder, he carried aouts away with him, and it was subsequently sold in large quantities for this purpose at Dresden, being known as 8eh'nirmhe wmxte Srd/o CSclinorr*s white earth). B5ttcher finding his hair powder waa heavier than usual, was induced to examine it, and this led to thi diacoreryaf (he nae of kaolin in porcelain. a\."!A.elBaBu,-ii\iwa tts am- piojDJeat was Jong kept a profguad eeoret. tWi oaSsWiiivntfsn. ik

T&rfEKT - PORCELAIN. 147

tbe Albreohteburg vfae n complete fortrees for the confinement of tte people employed, and "Be secret tmtil death" was placed on the vnUls of the worlishopa. The eueoimon of Botteher ware exhibited in thB firat gallery was prodnoed about the year 1796.

From Meiasen, however, the secret of the manufacture of porcelain spread, and Barlin, Munich, and St. Peterehiirg, about the middle ta the 18th centnry, boasted of their potteries. The Sivree works establishod at St. Cloudibefore 1695, bnt it waa not until about 27 that the uso of kaolin was introduced, it hniring beeu then rocently disooverod at St. Trieix, near Limogea.

In Englnnd a kind of porclin appears to have been made at yulham by John Dwighfe as far back as 1671. The earliest worka of importance, howerer, were those of Bow and Chelsea. The Biw factory appears to have been eatablisliod about 1730, but refer- . enoo to thia will again be made when describing tho collection of early English porcelain (p. ISl).

OoLOOHS used on Pottery and Pm-cdaiit. Tabh-ease No. 55. — Tho Dolouring materials employed in pointing pottery always conaisb of a mineral colonring agent, naaalij a metaUic oxide, asEOciated with some easily fusible snbatance, such as an alkalino silicate. On es- poenre to heat thia flux fuses to a vitreoua mass, which becomes ooloured by the metallio oxide, and hence all pottery -pigments may be simply regarded as ooloured glasaes. Those colours which are neiUier volattliEed nor decemposed by heat are applied to the ware when in the state of " biscuit, whilat the leaa stable coloars which would be injured during the baking are not applied until after glazing, the oalour beiug fasod by eubeeqnent exposure to a, com- paratively gentle heat in a mufHe.

la this case will be found an interesting aeries of porcelain colours from the works of Sevres and Berlin; a highly illnstratiye series of British pottery colours, prepared and present-ed by MeaarB. Emery, of Cobndge; a large number of specuneuB presented by Meaara. Uinton; and several examples of enam el-col onra fi-om Messrs. Maw & Co.

The process of transfer-printing on pottery has been explained at p. 142. The blue colour ho general on common earthenware ia produced by the oxide of cobalt. Examplea of printing will bo found distributed everywhere through the cei'amic collection.

It will now be desirable to dcacrihe the collection illnatrating tho history of tte potters' art in this country. Thia colloction occupies the entire aeriea of wall-csBes in this portion of the building, and commences widi Case I., on the eastern aide. The upper shelves of Cases I. to V. are occupied by a collection of medieval pottery, found mostly in the city of London. From this we pass to the early productiona of Staffordshire.

SxiyFoRDsmiLE Poiteri' and Pohcelais. IVall-cases on Huslem Side. " The PotierieB " have been celebrated iii thia country aa a locality

n which, from a veiy early period, earthenware waa manufactured.

Ve are not enabled to connect the early Staffordshire ware with the Romano-British by any existing links ; the earliest manufacture of which we havo any exact account being that of a coarae ware in 1500. The lutler-pol {(i. 1, 2, 3J was such an important object of the Staffordshire manufacture as to be the subject of an Act of Parliament in 1661. Plott, who wrote in 1686, aaya, " The butter they bay by the pot, of a loBg cylindrical shape, made at Bistlwa., in this oounfy, of h certain size, so as not to Jatne wj. -fsrajSis- at most, and yet to oonttan at leaat li pOTmia ol Ni-iAfcT: , 't

148 TffE tTlTNCIPAL tXOOit.

to au Act of PaTliaracnt made about 14or 16 years ago Tor regulating tto abuses of this trade," Dr. Shaw remarks in 1829, "that the common people of the district, at the present day, call Irish fcn' butter pot-lvHer." Pot-butter is still & common term in the 'westerfi counties, and frugal housewives talk of "potting" butter for the winter supply in the spring and early summer. The drinking vessel in the form of abear (G. 4) is bo formed that it cottld not be set down until it is emptied; hence the adage " 'ware the bear." The tygs(G. 7toG. 17) were the many-handled drinkingcups of those times ; each person drinking used a separate handle, and hence brought their mouths to difl'erent parts of the rim. The candlestick (G-.'23)has a dato upon it 1649,and the large dish (G. 24), ornamented in the centre with a. crowned lion, bears the maker's name, Thomas ' ToiT. These and anndrj mugs, porringers, &o. mark thepecnlia- rities of the manufacture of StaJi'ordahiro before 1680, up to which time the clays employed appear to haye been all obtained from the coal measures of the neighbourhood.

On the revolution of 1688 the Elers brothers oftme from Nurem- burg, and at their works, which they cstabhshed near Baralem, they made the red ware exhibited (G. 56 to G. 68), in imitatiou of the Japanese pottery. Many strange and some improbable stories are related of these potters and their jealous rivals ; liut certain it is that the Elers, from comjietition and annoyances, were compelled to abandon then- works in Staffordshire somewhere about 1710. Better clays were introduced, and the use of flint in pottery was discovered j thus the irean-eoloiO'ed imre and the v<hile too™ were gradually manufactured (G. 87 to G. 186). It will be observed that the formB are more perfect than they were ; this may be referred to the in- troduction of plaster of Paris loonlds, which were adopted from the poToeJain manufactories of France. The ornamentation is altogether of an improved description, and it is evident that great attention was now paid to this increasing branch of trade. Tte gl(u:e on this ware was produced by throwing common salt into the kiln.

Early esamplos of the transfer of engraving upon the glaze will be found.

In addition to the white and drab salt-glozed wai'e, this part erf the collection contains specimens of the peculiar aifaie tnare (G. 69 to 78) and torloisc-shell ware (G. 79 to 86) manufactured in Staffordshire up to the latter end of last century.

Wedginood's Wms. (G. 219 to 354 in upper shelves of "Wall-c VI. to X.). — This collection eshibita the remarkable improvements whict were at once made by a man who nnited great enerey of character with a fine appreciation of the beautiful. Wedgwood was born in 1730, tuid as a boy worked in a small pottery belonging t" his father, aa a thrower. In 1759 he commenced for himself in oi humble way, manufacturing small ornamental articles. He vei- much improved the Cream. Ware of the time, first made by Mr. Wood, and having introduced it to Queen Charlotte, he received permission to call his manafacture Qiieen.'s Ware. This ware and his knife-handles must be regarded as the foundation of Wedgwood's fume and fortune. Associated in partnership with Mr. Bentley' of London, Wedgwood succoided in securing the aaaistance of artists, such as Flasman, and the support of the patrons of art. From this time may be dated those beautiful productions which are so asso- coated with the name of Wedgwood — vases, cameos, medallions, and tbs like, wbicb iave not been excelled by any manufacturer since iia time. A. fair selection of these wiW. \ie tottuSi m X-He coUection, ' lowing tbo great variety of manufactures in v;\i\c\iVe en¥,?,ft?

Potteey Ajnd Poecelain. 149

As a fine example of Wedgwood's productions, a copy of a large Greek vase in the British Museum collection should be examined. This, the largest work executed by Wedgwood, was presented to the Museum by the late Mr. Apsley rellatt ; the original was formerly in Sir W. Hamilton's collection. It belongs to the latest period of vase-painting, known as the style of the Basilicata, and is supposed not to be earlier than 200 B.C. This noble example is mountea on a pedestal near Wall-case I.

A fine collection of Wedgwood's cameos has recently been arranged in two glass Cases No. 58, placed on each side of the pillar oposite to Wall-case VIII. The collection comprises 214 specimens, showing the character of the black Egyptian ware, or oasaltes, and of the famous blue and white jasper ware, a material which lends itself with admirable effect to the production of cameo- work. Further information respecting Wedgwood ware will be found in Miss Meteyard's Life of Josiah Wedgwood and Handbook of Wedgwood Ware ; and in Mr. Jewitt's The Wedgicoods, M. L. Arnoux, in his Lecture on Ceramic Manufactures, says : — It is not only that nature, when she gave the English people commercial and industrial genius, gave them also a soil richly supplied with the best materials for this manufacture, but it is to the exertions of some men of genius that England is indebted for this result ; and I think it only just to consider Wedgwood as the man who has given to the English ceramic art the powerful impulse it has preserved up to the present time."

Whilst the upper part of the Wall-cases numbered VI. to X. is devoted to illustrations of Wedgwood's ware, the lower shelves of these cases are occupied with examples of old Staffordshire pottery, showing the character of the manufacture as carried on by his contemporaries and successors. The series commences with some of the. old ware of Ealph and Enoch Wood, and passes on to the pro- ductions of Mayer, lieale. Turner, Shorthose, Adams, Wilson, Mason, and other well-known Staffordshire potters. The Spode ware may be regarded as a connecting-link between the wares in this series and those of Copeland and Garrett, which take a prominent place in the collection of modem Staffordshire products exhibited in the wall-cases on the opposite or western side of the room, to which we now cross.

Modern STAiroEDSHniE Pottery and Porcelain. (Wall-cases XXXV. to XXXIX., western side ; and Pedestal-case No. 62). — The present productions of the Staffordshire potteries are evidences of the successful attempts which are now making to equal the best works of other countries. Here will be folmd fine examples of the works of Messrs. Copelaud and Garrett, Messrs. Minton, and other leading potters. Modern English earthenware, which has of late years greatly improved, requires no description in these pages. The English porcelain is what is called soft orcelain, and is composed of three constituents. Kaolin and Cornish China stone, with hone joshes. Soft porcelain differs from hard by the presence of phosphate of lime, and by containing but a small quantity of alumina and a large proportion of vitrified materials. The soft porcelain cannot resist the sudden changes of temperature ; and generally, when you see a very transpaient pottery, you may be certain it will not stand the fire ; there is only one material which gives that property — it is the alumina, and that is perfectly opaque. (Amoiix.) Soft porce- glaze; the last, however, at a much lo>yer "kea.

150 THE PSmCIPAi rtrOOB.

OaBo fiScontame BsainpleB of the fineet productions of onr Ceramic mannfactGres at the time of the Great Ediibition of 1851.

Tariem, Carrara, or Statuarij Porcfdnin . Case 62. — By theee names a vitrified body irhioli in intended to imitate Btatuary nmrble is' dietinguished. It has not been introdnced many years, ajid the result obtained depends on the employment of a soft felspar instead of the CoTTiiBli atone. The fiibrication of Parian figures requires more dexterity than any other branch of porcelain mannfactnre. The proper misture of prepared clayand felspar being made, it ia mixed to tho conaisteuco of cream, technically called " slip," and in this state poured into moulds of plaster of Paris, which absorb the water from tho clay. Those figures otb coat in a great number of separate pieces ; aa many as 50 monlds are required for some pieces, and muon experience and a knowledge of the human figuro are re- quired to imito them into one. Theflgurcbeingformedfpomthe cast pieces still requires much attention. In the proceaaes of drying and firing the model shrinks no less than one quarter, and as tha contraction ia in all directions, and ia determined by the thickness of the body, Tarioas allowances have to be made. Again, beinr made of a fusible material, these would loose their shape, and fall, if not Bupported all ronnd with prips of the same material. Tho firing itself requires great attoation, as on it depends the colour of the figure — tho colour being due to a ailicate of the peroxide of iron which produces the yellowish white which is so agreeable in these' figures. '

The speciniOBS exhibited will HufGciently show the applicability of this material to the reproduction of the fiiiest works of act. J' cupabilitiea are great — but as yet, owing to the diffionltiea of man faoture, it has not been possible to render these poroelaiu figures cheaply as conld be desired. In tbe education of the people, t advantages to bo derived from rendering them Ibmiliar with the most beautiful objects are so evident, that no effort should be spai'ed to improve this montifacture, and to place the results within, tho i"eaoh of every one. SWrn CoUa. Case 62. Oalateit and other jigwes in fheLovrcr HalL This term signifies literally iaked earik, and it may therefore extended to numerous articles of pottery.

The revival of the manufacture of terra cotta in England belongs to Josiah Wedgwood, who in 1770 miiuufacturod it largely Stfttfordshive. In 17S0 a maiiiifacturo of terra coita was carried in Lambeth by a lady of the name of Coode, and until within t... last few yeai-3 by Coade and Sealey, who made large articles, sucli as statues, Tasea, &c., anij architecture daoorations, in the produc- tion of which such artists aa Bacon, Eoasi, and Parrietta were engaged. Eoesi manufactured the cspitals andstatues of St. Pancraft Church of this material; and the frieze of the Opera House ir - Haymarket is from the maiiufaiCtoiy of Mr. Bubb. in executing a work in terra cotta the original woi'k ia firat lodelled in clay, and a plaster of Paris mould ia then taken froir ,JSia. Sheets of clay are beaten on a bench to the consistency 0: iaiuter's putty, ajid pressed by the bands into these moulds. Affcel aie clay nas been allowed to dry a little in the planter mould, tli(

defects iriici appear o is then left to diy gradually, and it \arae, -ptu-ga ate -oijerb applied; Tehea enflSeiently dry for \>ak\rvs,it is couefti-XaNi&d

POTTB B T AND PORCaJOK. !5t

and the fire beiug gmdually raised, it is baked, nnd tbo article boeomea Terra coUa. The bcnC lihouM be iil' eaffident intoniily to blendand partly vitrify tbo mataiiala of nhitlitlie mass in cumpoBod, nitboub melting or diatortiug the waro. As soon as Ibis temperUnre is obtained the firinif ie stopped, and ail apertures closed to prevent iJie admiseioti of air. "When ibe kiln hs cooleil, the liuiihecl terra QotCas ai'o withdrawn, Tlie example of Galatea will convey an idea of the size ta which sucliVorks can be carried. The ligare of Australia, modelled by John Bell, and manufabtnred by Mr. Blaiih- field, -which is at the Crystal Palace, Sydenham, is at the height of nine feet— this was buml in one piece. Several tigurcs equally colossal have been monnractared at the Millwall torrn cotts works, and at the establisbmeiit of Mr. Minton, Sloke-npon-Tretit, (6m Higlory rmd Sfanufatli're of AndetU nnd Modem Terra CotUi, In J. M. Bhuhfidd.)

FjUEZES, Enamelled Bbicu, Tileb, &C. SpcUnfot 'Mdar Daluttrade cit Eiulem, Suk and wider W'atdoica.

The Mezeg, of which there are four, ore in imitation of the della Bobbia ware ; tho other exaniplea of ornamental parthenwjiro aro intended to show its applicability to tho decoration of rooyiH and other architectnral parpoaes.

The hollow brioKB are thotight |to combine the advantages of strength and lightnesB, and, from the free oircnlittioo of air throngh the perforationg, to ensure perfect dryness to the walls. Those are mannfactured by Prosser's procesa (p. 46) ; they are then painted and enamelled, bo that the interior decoration of on edifice is pro- duced as the wall ia built.

Some excellent examples of modoni enamelled ware, applicable to oriiomontal architecture, manufactured anil presontud by Mensra. Maw and Co., will be fonnd In the upper ptu'C of Wail-cnos XXXIX. toXLIV.

Enough FoBCEma. Wall-caaos XL to XXXI7. tinder Wiadoivs al StuiWifrw End.

Dow PoRCELAtH. Cam XI., XII.— Tho Bow porcelain works were probably eetablisbcd about tho year 1730. and in 1775 or 1776 they were sold to Mr. Dnesbury of Derby.

A writing on the cover of a bos in the British Muaeom, contain- ing a porcelain bowl, informs na that " the above manufactory wob carried on many years under tho firm of Messrs. Crowther and Weatherby, whoso names were Itnoivn almost over the world ; they employed about 300 persons ; abont 90 painters (of whom I wm one), and about .200 throwers, turners, Ac, were employed under one roof" The writor, who waa the enameller of the bowl, aigna hia nome, T. Craft, 1790, Of late yeaj-s our knowledge of the old Bow porcelain has considerably increased, principally through excava- tions conducted on the site of the works by Messrs. Bell and Black in 1868. Some of the fragmentary piecea then found are hero exhi- bited, together with a number of typical specimens which will servo to ve an excellent idea of the character of tte productions at this factory.

C'HELSEi PoBCEtiiN. C'nea XIII., XIV.— Under tlic ansiiioea of tho Dnka of Bnckingham, in 1676, some Venetians establiahed at Chelsea a gliWB -manufactory. As the Venetians well nnderetood the manu- faotnre of opaque glass (aee tbe Venetian Coae, So. (Ki\,ttieU'Mss.\- &on Irom this iiumufacture to ttat oE povciAa\3i.-?iB.9 wsa. V\.ie,t.->a.

153 The Ebmcipal Sxoob.

that the Elera (Ehre u-are, p. 148), when they left Staffordshire in 1710, joined these works, and greatly improved the ware and the deaigns. The Chelsea potters are stated to have obtained Kaolin from Chinn, but this is highly improbable, as they obtained sand from the Isle of Wight, and probably procured from Dorsefahire the olaya then well known. G-eorge II. especially encouraged the Chelsea works, procuring models, workmen, and materials &oin Saxony and Brunswick for them. The greatest excellence was achieved, and the works were in the height of snccess between. 17o0 and 1785. A set of Chelsea porcelain is stated by Horace Walpole to Lave been presented by the King and Queen to the Dake of Mecklenbnrgh, which cost 1,2001. {Marryat'a HUtory o/ Pottery ami Porcelain.)

These works were discontinued about 1765, and the models were puTchaaed for the manufactory at Derby.

Deebv PoBCTLiis. C'weB SV- to XIX. — These porcelain works were founded by Mr. William Dueabury in 1751. Not only did the Bow and Chelsea moulds find their way to Derby at the closing of those works, but many of the workmen and artisM were attracted thither, Derby may therefore he regarded as having united in another locality the porcelain works of Bow and Chelsea. Boswell, recording Dr. Johnson's visit to the Derby works, says that the great doctor .ired the beauty of the porcelain, but objected to the price, obaervJ! g "that he could have vessels of silver of the same size as cheap as what here were made of porcelain." The Derby porcelain, works continued auttl 1848, they were finally closed, a minor maajnfactory, however, still remaining. The typical pro- daotiong of the worka are fairly ruproaented in this series, and information on the factory and its products will be found in Mr. Haslem's History of the B&hy Worke.

Plymouth Pohcel.un. Cases SX., XXI. — The worka at Plymouth were established by Mr. William Oookworthy, who has been already mentioned in the notice of Kaolin [p. lil). Lord Camelford united with Oookworthy in obtaining a patent, and establishing the worka. His Lordship in a letter to Mr. Polwhele says: — "The difflcuUies ftiondin proportioning properly those materials, so as to giveexactly the necessary degree of vitri&cation, and no more, and other niceties with regard to manipulation, discouraged ns from proceeding with this concern, after we had procured a patent for the use of our materials, and expended on it between two and three thousand pounds. We then sold our interest to Mr. Champion of Bristol." — (See Prideaiiai's Belies of Oookworthy.) Plymouth poi-celain is dis- tinguished by its great hardness ; it has become exiiemely valuable, and several excellent pieces, bearing tho characteriatic mark — the BjTnboi for Jupiter — are preserved in this collection,

Bristol Porcelain and EiBTKnywABE. CofiesXXU., XXIII.— It is known that Mr. Eichard Champion commenced the manufacture of porcelain in 1768. Oookworthy and Champion appear to have been associated at one time in tJio manufacture, but in 1773 the patent right passed into Champion's sole name. He transferred the patent to a company of Stoffordalire potters probably in 1781, and the Bristol manufacture was then abandoned. Fine examples of Bi-istol porcelain are" eagerly sought by collectors ; the small col- lection here exhibited shows the charaoteristic features of the wsrre, and tie mark, a. cross, which was usnally employed. There is also a collection of Bpeoimana of old Bristol eaTthenwaro and delit on the lower shelves of these cases. Fov a ful\ hiators o>i \jVss -siQE'ta liia

rtnrtXT AND POBCELAIN.

EocKisGiiiH PoKCELiiu Aso EiBTiiEswAnK. Cage XXrV. — The beaatiful porcelain here exhibited vraa mannfoc Cured at Sainton, near Eotherhum, Yorkshire. It takes its name from the llurqaia of Bockingham, npon whoe eiitate the works were established in 1757. At that time, however, it waa onlj a facLoj'jr for making coorsa eaiihenivare, and the porcelain was not produced until ]ti3o. The famous brown glazed pottery known as " Bookmgham ivaro" was nlao made here. The works were abandoned in 18-.

"Worcester Pohcewim. G<ues XXV. to XXX.— Tho Worcester works were established in 1751, through the esertions of Dr. Wall, a phjaician of that rity. Tho early productions of Worcester were mostly imitations of China and Japan wares. It was, however, highly esteemed for its good qualities, and this waa probably due to the empIoyracQt of the Oornisli Kaolin. In 1783 Uie Worcester por- celain works were purchased by Mr. Thomas Flight, from whom, they afterwards pasac-d to Messrs. Flight and Barr. The iiiatory of the works wiU be found in Mr. Bma's CeiUunj of Putting in

The large collection of specimens in this series serves to sbow ttia principal characters of the ware at dilferent periods. Attention may be called to the early eamplcs richly ornamented with birds aiLd insects painted in panels on deep blue scale-pattern ground, and to specimens of early trauslbr printing on white glazed porcelain. The King of Prussia mug, dated 1757, is oiio of the most intei-esting examples in the collection. The saccuasive stages in the develop- ment of the mauufacturo, up to the present day, may be traced by studying the scries here exhibited.

Salopias PoriEar and Porcelain. Cxca XXSI. XXXII. — A small pottery was established at Brosely, in Shropshire, about the year 1751, and a superior kind of porcelain waa afterwards manufao- tnred under It, ThomaB Turner, who came from the Worcester Works in 1772. The Coal|)ort or Coftlbrook Dale Works, stiU exist- ing, were founded by Mr. John Eoae, who originally settled tab Jackfield, and then removed to Coalport, and ultimately pui'chased the Canghley Works. Examples of both the old and the modem products are exhibited,

A large series of specimens of Messrs. Maw's modem majolica ware, manufactured near Brosely, in Shropshire, is exhibited on the upper-shelvea of wall-caaoa XXXIX. to XLIV.

Swansea Potteey and Porcelais. Owea XXXIII. , XXStV.— About tho year 1753, a pottery was established at Swansea; in 1802, Mr. Iiewis Weston Dillwyn purchased the works and introduced great improvements in the charatfcer of tho ware and its decoration. It was not, however, until 1814, that tho beautiful paste of the Swansea porcelain was produced. The Swansea porcelain is remarkable for the correctness of the natural history subjects with which thoy are embeUiaheil, Mr. Dillwyn having been much devoted to the study of this science. In 1817 tho porcelain manufactory was abandoned, earthfinware alone being produced nutil .the works were finally abandoned in 1830.

Nahtgasw PoBCELiis, CiMH XXXIV. — Several examples of the fine porcelain made at Nantgarw will be i'onnd in this cose. The manufacture was commenced in 181S by two iaiuwiui wiiitos.i, Billingsley and Waiter, and tho works wete "N5s1K>

THE PaiNCIPAL TXOOH.

LowESTOW Pottery and Pohcilais. Goes XXXIV, — A small col- lection, illuHtrating thoso manufEict'area, is hero exhibited. The prodaotioa. of porcelain was attempted at Lowestoft, in 1756, and successfully carried out the foUowina year. The period of greatest prosperitf was between 1770 and 1800; in 1802 t!iB works -weio abandon ed.

The series illustrating the liistory of the mannfacture of British porcelain ia here concluded, but itremainB to notice several interest- ing ooUactionB of old English earthenware, which will be found in the lower parts of the waU-oases running along the western wall.

Leeds wake, &c. Cane XXSV. to XXXIX.— It was in 1760 that pottery was first manufactnred at Leeds. In 1786 it have been in aflonrishing condition, Mr. Green, the then proprietor, jjublishing a book of patterns, of which a copy is in the lita-aiy of this Institu- tion, with tha title of " Desimie of SKiidri/ artieles o/Qiieen'a or oreant~ colowred cairtlumwaro, mamtfacturcd by Sartley, Greens, and Oo at Leeds pottery. The taiae enamolkd, 'printed, or omamcTiicd wUh gold to any patierji; also mlh coats of arms, cypliers, landscapes, 3fo., Leedt, 1786. The potter's field is still known by that name in Leeds, and the bone-mill has only disappeared within a few years. The visitor will observe the fine cream tint of much of the Leeds ware, its brigbtncaa and elegance of form, and the delicacy of the perforated work which forms so marked a feature in its decoration. Associated with the Leeds ware are a few esamples of the products of other rtirkshire potteries, such as the Son, Oastleford and Ferryhmlga wcrka. There is also an extremely rai'e specimen of Phee'a tcare, manufactured at an early date at the Manor House, York. We then pass to the samples of Liverpool poilery. According to Mr, Mayer, the first notice of Liverpool pottery occurs in the year 167i. During the laetcentuiy several manufactoi'ies were in existence, the principal being those of Alderman Shaw, Messrs. Sadler and Gi'een, Chafiers, and Pennington. Some large delft punchbowls of Liverpool wars are exhibited, and also some speoimena from the Herculaneum pottery, on the opposite side of the Mersey, established in 1794 and abuidoned in 1841.

In an adjacent case will be found esamples of old Newcastle, tinglio'ui, and Wrothm ware ; whilst the shelf above ia devoted to the exhibition of modern ware, including the beautiful torra-cotta made at Wciiionihe, near Torquay, and the oraamontal stone manu- faotui'ed at Lamheih fay Mr. Doalton, and decorated in an original stf'le by Miss Barlow and other artists. The old productions of Lambeth, Yivazhall, and Ftilham are to be found oa some of the lowei- shelves of the caaea against the western wall ; and the bottom ebelf of these cases supports a fine series of old Sclftioare, partly English and partly Dutoh, Here will be found some curious ex- amples nf delft wine-pots, caudlo-, pill-slabs, puzzle-juga, punch-bowls, and dishes ornamented wilh rude figures of tbo kings and queens of Erglond from Charles II. to Queen Anne. A few Qxamplea are exhibited of modem Iriik porcelain, mode at Belleek, in county Fermanagh, and notable for the beanty of its Instrous glaze and the elegance of foiTo, copied from natural objects.

In the gallery a series of illustrations of ancient wnd modent

'/et'imanso/Ji'cn'eign Pottery and Porcelain ia in course of arrangement.

Araouff the specimens will be found esaiflp\ea o? iiwio.fc pottery

from Mexico, Peru, New Gvanads-, India, Baiiars, "SAttaw., raii.

r

Borne: and of moileni Mexican, Indinn, Bgyptmn, Zulu, Italiim, Portuguese, and Spanish pottery, Of Chineae poroelftin some Bpeoimeiis will be found with the raiaxaela, &c., in Case tS.

It hae not IJBcn coneidered necesBiuy td do more thati introduoo very brief deaoriptiona of the ohjecta in the Collection of Pottery and Porcelaia, iinoo the HpocimenR nre described in detail in the Catalogue apBoially devoted to this Department.

Oases 56, 57, 65, 68, 69.

The manufacture of glass, from its intimate relation to certain branches of ceramic art, receives appropriate illustration in this section of the Museum.

Olaas consists of a fused mixture of various acid silicates, uanally tmnsparent and insoluble, and always destitute of crystalline strac- ture. In a free state silica or silicic acid is highly refraototy, hut 'when associated -with certain metallic osidea, the resulting com- ponnde are often eminently fusible. The degree of fuBibiBty en- Qved by those artifloial silicates is dependent partly on the nature )! the base and partly on its proportion, those silicates which contain in exceaa of base being moat fusible, and therefore most easily worked. In practice, however, glass always contains a large pre- ponderance or ailica, since it happens that the basic silicdtes, espe- cially those of the alkalies, are frequently soluble, and hence to a great extent useless for those purposes to which glass is ordinarily apiied. As an example of a aolnblo alkaline silicate, we may refer to the " wnter-glass " already m.entioned at p. 45.

Eseltiding those oxides which are introduced simply as colouring or decolouring agents, the bases practically employed in glass- making are potash, soda, lime, and oside of lead, hat for these bases other oxides may be substituted, as in the zinc- and manganese* glasses exhibited in Case 56 ; whilst, on the other band, the silica may be replaced by horacio acid, as in Faraday's "heavy glass," a ailico-borate of lead, of which a specimen ivill be found m the eamo

DeviMfiai Clase. Cetss 56.— One of the most essential properties . of glass ia its amorphous or non- crystal line character. Its com* ponent silicates, as definite chemical compounds, possess a certain tendenoy to crystftllize, but the rapid cooling of the fused mass effectually preventfl crystallization. If, however, the glflsa be maintained long in a heated condition, its individaal silicates have opportunity to crystallize, and the gloss then, losing its "vitreona oharaoters, beeomea dcvUrifiai. From their complex composition' bottle and crown glass are most ausceptibie of suffering this mole- OuTar change, and several specimens of bottle "matal" aieshibited in which certain silicates, having separated, appear as crystalline products embedded in a vitreous matrix. Under other conditions the entire raasa of glass may be dovitriftod, as in " E&Hm.Mr's yorcs- toin," of whieh samples are exhibited. This peculiar sabatanoe ia prepared by subjecting glass for a considerable time to a temperature somewhat below its melting point, the result being an opaque white flbrouB product, esceedtiigly hard amd tongh, and capable both of mthatanding sudden alteruatiooa of temperature and of resisting the action of chemical agents.

Flist Glass. Caee 56. — This ia composed of a miictiire of silica, alkali, and oiide of lead. Specimens of the raw matertals will be found in this case. Formerly the ailica was introducod in the shape of calcined flints, whence the name " flint " glows, but at the present

Mft- THB PBISCSPAI. FLOOR,

day sand alone ia omployed. The chief localitiea in England for glas-making eand are Alom Bay, Lynn. Aylesbury, Wareham, Eeigate, and the New Forest; bat it ia not always of aufBcienb pnnty for flint-glaaa mauirfaotui'e. Iiarge qnantitiea are also derived from f ontaineblean, in France, and from Asterica, Aoatralia, and New Zealand. The sand ia prepared for use by simple washing and calcining, or if necessary by treatment with hydrochloric acid. The alkali in flint glass ia usually employed in the form of pearlaah, an impure carbonate of potash, the acid being expelled during fusion. The high lustre, great density, and easy fusibility of flint glaaa are due to the presence of oside of lead, which ia largely introduced into its composition, chiefly as red lead.

To remove the colour imparted to the glass by impurities in the raw materials, especially iron and carbon, certain oxidising agents are always mixed with tne raw materials. Of these oxygen-yielding substances, the most common arc nitre or saltpetre, arfienioua acid or white "arsenic, and pyrolusite or peroxide of manganese {p. 84).

The following recipe for the composition of fine flint glaea was giren by the late Mr. Apsley Pellntt : —

Carbonate of potash - - - 1 cwt.

Eed lead or litharge - - - 2 cwt.

Sand washed aud burnt - 3 cwt.

Saltpetre - - - - 14 lbs. to 28 Iba.

Oxide of manganese - - 4 ok. to 12 oz.

The ingredients reduced to powder, and mixed with a due propor- tion of " cullet," or broken waste glaus, are fused togethei' in lire- clay melting pots, covered ivith a hood or dome, to prevent the flames from aflecting the "batch," or mixture. One of these oniciblea is placed in the western gallery, and the mode of arrang- ing the pots is shown in the model of a fiint-giass fomace which is placed in this case. These pots are filled but once a week in a flint-glass house, usually on Friday or Saturday morning. The various charges aro melted down and fresh matter supplied, until in about 12 or 15 koars the pot is full of melted metal. Ail' bubbles and striee thou abound, and they are not expelled until 30 or 40 hours have elapsed; during that period the glass becomes homo- geneous. Saturday and Sunday aro the days when the furnace requirea the greatest heat, so that the working may be commenced on Monday morning. When the melting and refining ai-e completed, the temperature is lowered until the metal becomes sufficiently viscid and plastic to admit of free working.

The details of manipulation are illustrated by a, series eshibiting the successive stages in the mannfactaro of a wine-glass ; and sevenJ of the simple tools of the glass-worker are oxbiljited, viz., the pvcellas, the spring tool, and the wood tool. The mode of blowing glass in metallio moulds is also illustrated.

The finished article passes from the bands of the glass-blower at a high temperature, and is immediately transferred to the " lear," or annealing oven, to prevent the excessive brittleness resulting from sudden cooling. It has been already stated that the particlaa of melted glass possess a certain tendency to crystallize, bnt that this tendency is resisted by the rapidity of cooling. The conditions, therefore, being unfavourable for crystallization, the particles are forced to assume a constrained position, which is necessarily greatest at the surface, where the cooling has been most rapid ; and hence cbe euperScia] layers are iu a state of tension in relation to those beaea,tb, the sligbteet force being snfficiont to dlatorb the unstable eguiiibriuia and pj-oduce dibruption. Tke cMio-ia Bologwi

phiaU" placed in thia eaae are sftmjjiea of nuannealed filass, the woil-known " R-uperfs tiropi " are similar esnmplm. The object, therefore, of annealiog is to cool the glass with sufficient elowneaa to prevent the inconvenient brittleneea of unannealed ftlass, bnt at the same time to avoid soch tardy cooling as woold indnco devitrification.

The final operationa of grinding, polishing, and engnn'ing are illnstrated by Hpecimene ; and a collection of modem objects in flint glass will be fonnd in Coae 69, described at p. 161.

Among other speciniena in the case before ns attention may be directed to an example of eamto inenalation of ranch intefeat. The flre, nsnally made of porcelain clay and sand which haa been pre- Tionaly fnaed with carbonate of potash, is forraed in a plaster of Paris mould, and slightly baked. It is then heated to redneBS, nod being placed within a cylindrical flint-glass pocket, the open end is heated and welded together by pressure, so that the figure is in the middle of a hollow hot mass of glass. The whole ia re-warmed and the workman eihanats the air by hia mouth from within, by means of the tnbe to which it ia attached, nd thus by atmoapheric preaanre the whole becomes a homogeneona body.

An itun-ueled inscription is another example of a similar character : the letters are di-awn npon a piece of glass with a vitrified blaok

Eaiut, and bamt in; the inscribed glaea is introduced at nearly a red eat into a glass pocket, and treatwl aa already deacribed. Bricks of glass containing inacriptiona are now inserted in tbe foundation stones of buildings, to tell the tale of the founders, and of tbe state of thia manufacture, ages after tha bodies of those who fabricated mtfaer are resolved again into their primary elements.

Bottle Glass. Case E0, — The variona stages in the proceaa of forming a wine bottle are hgre shown. The raw materials employed ' 1 the mannfacture of common bottle-metal are of the ooaraest

description, consiating nsually of rough sand, soapera' waste {the alkali employed), gas limes, common clay, and rook salt ; but the composition is by no means uniform in different works.

Plate Glass. Gate 56. — All the cases in the building may be regarded as examples of plate glass; and the glass in the roof shows the character of the ronghened plate. Some examples in these casea furnish instances of peculiarities.

The composition of plate glass varies considerably ; sand, aalts of soda, or of potash, lime, and ' ' cnllet " or broken glass in difl'erent proportiona are introduced. Peroside of manganese, arsenic, aiid saltpetre are employed as decolorizing agents; and often oxide of lead, to impart a brilliancy to tbe glass. The manganese and the other substances arc used to secure the oxidation of the iron, or carbon, which may exist even in the purest materials. An ei;oesB of manganese produces a violet colour ; and even when at first there is no appearance of colour in the glass, it will upon exposure to sunshine be gradnally developed, Instaueea of this pink or violet tint are eshibited in the cases before us, and the same thing is strikingly shown by much of the plate glass in the roof of the building,

Plate glass ia cast upon flat metallic tables, or casting plates, which are warmed previously to tbe flowing of the glass from the cuvette or ci'ucible to prevent its cooling too rapidly ; whan properly flpread, which occupies but a short time, five minutes only being required, it ia passed into the annealuig oven, -wVeie 'Oo. ' IB from 8 to 14 days.

]58 The Frincipal Floor,

The auuealine; proceaa being completed, the plate is snbiected to the operation of polishing, which ia effoeted by meatia of riholhar (oxide of irtm or eroaaa), rubbed over the plates with a heavy mullei' OP weighted board.

The varions stages in finding and polishing the plate ore illua- troted by a series of spooimens.

Chowkamb Subet Glass. Wesicru Galk-rii.— In the gallery above the pottery on the weateni side will be foiuid & series showing every stage of the prooesa of manufaofcuring sheet and crown glasa, with exomplea of the tools employed.

C'roiiin glass is composed of a mixture of sand, aoda-8:Sh, and lime, which, after partial fuflion in a "fritting oven," ia mixed mth a proper proportion of cnllet, or broken refnso elass, and the whole melted la a glass pot, "When thoronghly f ased the workman gathers upon the end of a long iron blowpipe a sufficient quantity of the melted glass ; and having flattened the mass by rolling upon a "niarver," or iron tablOj blows a pear-shaped flask, which is enlarged by repeated reheating and snbaeqnent blowing. When sufficiently enlarged, the glass globe is transferred to the " pontil" or punt, and the blowpipe having been removed, the "flasher" rapidly rotates the heated globe, whioh, expanding by the centri- fugal force developed by rotation, is finally converted into a flat cii'cular disc ; and this, after removal from the punt, ia conveyed to tlic nnncaling oven : the point at which the punt adtcrcd,, being thickei' than the snrrouadiiig portion, forms the mark called tlie

The manufacture of sheel or siread window glass differs somewhat from that of crown glass. Instead of being blown into the shape of a globular flask, the ball of melted glass is extended into a conical form by a swinging motion, and then .elongated into a cylinder, which ifi cut open by means of a drop of cold water falling along a line which has been previonaly heated by the applicatiou of a red hot iron j the cylinder ia then, flattened upon what is called the spreading plate, or the flatting atone, and the sheet of glass so formed subsequently annealed.

Miscellanea. — Case 56 includes, in addition to the objects already described, a series of modern VcneHaM etiamel {p. 16i), and a QoUection of glass heads used in the African and Indian trades. The art of makiug glass beads was first discovered at Murano, where the trade is stillgreat; it ia stated that they make 200 diSerent shades of colour, Here also wiU bo found pieces of enamelled la,s, for- merly manufactured at Bristol ; and some examplea of painted and etched glass, &c. Etching an glass is commonly effected by covering the glass with a coating of wax, and then with a needle reraoving it along the lines to he etched. The drawing being formed, the glass is eiposed to the action of hydro-fluoric acid, liberated Irom fluor-apar by the action of anlphuric acid and heat.

The remaining objects in this case are for the most part eufSciently explained by the accompanying labels.

In the Historical Series the following will be found to be of especial interest. The importance of a collection of ancient gliiBa, accompanied by analyses thereof, ia connexion with modem illus- lj;atJon3 of the use of sands and alkalies, must be evident to every

Akciest , Case 57. — The ti-adition of the discovery of glass ibjp- the accidental fusion of sand ou the tank of Vbe viver Belus can scarcely bo received ; evidenee appears tbrovi 'OQ.e ii&ccrsB-rj -erj

Glass.

Iw

innoli further bitck in time. Ic is clenr that in the iifire of Moape nnd Job the art of mnkiiig glass was known, it U evideDt, the enampiee preserved in the*Eg]rptian tonib. that the pooulo of tboie dafB were familiar with the jjrocesBes of pressing and mouldiiiK glaas [lee taamples). Babylonia, Assyria, aui) Obnldea bave enoh afforded specimens, which provo not merely that the fiieion of silica with Rn alkali could be oflectcd — thia ivaa shown by the enamelled bricks — bat that this fased mass could ha variously coloured and worked into articles of ornament. The researchos of Layard, Baw- linsoD, and Loftua have brought na the l>eads and other ornaments worn by the ladies of the days of Assyrian splendour, frJtind in the great room of the palace of Nimrond; while amidst tlie relics of 'brick-bailt ]3abyIon similar illastratioiis of the fictile art have boen foond {soe examphi).

The apecimena of Greek glasg of the aamo general character hav(> considerable interest, as showing the progress of this manufacture ; and we must aseooiate in our coosiaeration those illustrations of glass which are regarded as Bornan, having been found at N'ismcs, and Treves, and in London, associated witn other relics, marking the spots which Rome included within the bounds of her empire.

It will bo observed that these glasses are variously colonred, that some show the process of moulding, others are blown, and some have been cast or else fattened. The Fompeian and Roman arohi- tecta arc known to have used glass in their mosaic decorations ; Bnd glues ia said to have been employed for admitting light to the hoases in Pompeii. Some of these examples of glass have been analysed in the laboratories of tho cstobUshment : the following are the results ; —

—

I"

Tfl'Bg

I-B(l

O-Bs

o-4a

Tine glass . . . .

g'OO

trace

M'W

FlatledElaiB - - -

n-K

tnux

o-w

7'

0-M

U-M

Tl-*9

fii

1-M

™

8-1*

tmee

The cinerary urns of croon glass will be inspected with much interest; of these Mr. Apsley Pellatt writes, "The round vases are of elegant forma, with covers and tivo double handJea, the for- mation of which must convince any one capable of appreciating the difficulties which even the modern glflsa maker would have to surmount in executing similar handles, that the ancients were well acquainted with the art of making round glass vessels." One of the bottles found at Niamos has been fonnea by being blown in a mould. The laahrymatarics have been so called from the romantic notion that those bottles were filled with the tears of the monmera for the dead, as they have been usually found iu tombs; the re- ceived opinion among tho ajitiquaries of the present day is, that they contained the unguents and oromatics which it was usual to deposit with the dead.

The Human jfaas b(n)ils, from the number of them which have been discovered in various parts, must have been much in use. It is TOPioos and interesting fco find rock crjBta\ avA a.'sfe iwaSia aswi- ciated with glass ; thus indicating t\i6 vaVaewdaTO.-aft's.iariftVtfai

160 The Phtncipal Flooh,

Bet upon tbe whito transpareat glaaa of thoee days. In this caae will be found some esamplea of Druidic bpada. Theae beads weia called GJaiii Neidyr, from i/lain pure and holy, and neidi/r e. enake. It is corioas to find these beads in the ancient British tombB, in tha graves of our Roman conquerora, in tbe tumoli of tbe Anglo- Sasons, and at tbe present day in tbe Asbantea diatrict of Africa j while bead in all I'eapects similar is made in Yenice.

Another set of beads fonud in Britain are ahown ; these consist of glnea and rock-cryatal, and were found with iron weapons in stone-sided grave within a tumnlua, near the Tynwald Hill, Isle

Veketian GrLiss. Owe 65, — Venice for a long period during the middle agea was celebrated throughout Europe for its glass. Familial' with the manufacture from an early date, the VenetiauB, on the capture of Constflntlnople in 1204, profited by their inter- course with the East, and Blass factories soon became so numerous at Venice, that towards the latter part of the thirteenth century they were removed to the adjacent island of Murano. During the fourteenth century the art was principally directed to the produc- tion of beads and other trifiea, but a freah impulae was given to the manufacture on the fall of the Eastern empire ; and during the fifteenth and aisteenth centuides Venice produced those peouliEir examples of glaaswork, which, from their ingenuity of design and delicacy of execution, acquired a wide reputation, and for a long time, defying itnttation, enabled Venice to maintain a monopoly of the manufactnrB. The case before us oontaina a fine collection of these skilful productions, of which the principal varieties may be briefly described.

Ydro di irina ia fine lacework, with intersecting lines of white enamel or transparent glass, forming a series of diamond-shaped sections, the centre of each having an air bubble of uniform size ; this glass was executed almost with the preciaion of engine lathe turning. The large cup and cover is a fine example of this variety, and there are some other sraaller specimena. Case 56 contains some speciraena made in imitation of the old vetro di trina,

Froeted Glass. — The art of maki this glass appears to have been lost nntil it was revived in the Falcon Glass Works about 1850. Mr. Apsley Pellatt thus describes his process ; "It has irregularly veined marble-like projecting dislocations with intervening fiaanrea. Suddenly plunging hot glass into cold water produces oryatalliue convex fractures, with a polished exterior like Derbyshire spar, but the concave intervening fissures are caueed, first by chiiling and then reheating at the faruace, and aimultaneously expanding the reheated ball of glass by blowing, thus separating the cryatala from each other, and leaving open fisanrea between, which is done preparatory to forming vases or ornaments. Although frosted glass appears covered with fractures, it ia perfectly sonorous." The ancient frosted glass ia repreaented in Oase 65 ; the modern in Ofwe 56.

Filigree Glass. — Filigree canes of plain, coloured, or opaque white are arranged in a mould, a aolid ball of flini glass is then heated so that the canes of glasa adhere to it ; these are marvered or rubbed into an uniform mass ; it is then covered with a gathering of white glasa, and is formed into any shape.

Case 66. — The series of ancient Venetian glass ia continued on the lower ahelf of thia case, and several varieties are here represented which were not eshibitod in tbe preceng caaee. Theae include examploB of the Venetian ball, Schmeltz giaaa, &c.

" The Venetian Ball ia a collection of waste piecoa of filigree glass

mglomerated together without regular design ; thia is packed into a pocket of transparent fflasB, which ia adheiiTely ooUapsed upon the interior mass by sucking Dp, and thus producing outward pres< sure of the atmosphere."— (PeifaSi.) An mtereBtio ball ia in tlie collection, in which a dark purple glass, covered with air babbles, IB enclosed in a traiispareiit glass of another cliarocter.

" Millejiore is more regular in design than the boll, bat of the same character. It was formed by ptaoiitg lozenges of glass, cut from the ends of coloured filigree canes, ranging them in regular or irregular devicea, and encasing them in transparent glass." — (PellaU.)

Sehmalli Olasa, the character of which maybe seen in the specimens at the Bonthern end of the case, was formed by welding together Tarionaly-tinted glaases until the colours become irregalarly blended and the mass Hsanmod somewhat the appearance of a yariegated marble.

The Venetian Plate and another specimen of opaque glass appear to resemble in many respects Reaumur's porcelain (p. 155).

Out Qeruan Glass, &c. Oaee 66. This case contains several interesting esaraplea of early German glaaa. The tall cylindrical beakers, ornamented with escutcheons and other designs in opaque enamel coloura, were peculiar to Germany during the sisteenth and eeTenteenth centoi'ics ; and two of the specimens before ub bear the date 1652. A smaller drinking laas, with a delicatelv executed painting in brown oamaieu, furnishes an esmmple of the style of tnonochrome decoration practised by the Germans in the eeyenteenth century.

Some Bpecimena of old Butch and French glass are aUo placed in this case. On the uppr shelf is a goblet of engraved glass, formerly used by Charles II. Through Sir Sobert Gayer, one of hia courtiers, it came into the posseesion of the Hodgson family. As showing the make and the engraving of glass in the Beventeonth century this specimen is iutresting.

Modern OBKiMENTAL Glass. Cimea 68, 69. — Before passing to the strictlymodem esamples of glass-making, attention may be called to a few specimens of ofi Brielol glass arranged on the upper shelf in Coie 68. Much of the modin glaaa was obtained from the great Exhibition of 1651, and ia noteworthy for its beauty of colour and elegance of decoration.

Telloto Glues. — The fine yellow on the apeoimens in these cases are produced by silver ; the yellow of the ordinary glass for ornameatal windows may be produced by charcoal, iron, or antimony.

Canary Ydhw, or Cranium yellow, is the result of the combination of the oxide of uranium with the flint glass. This glass has Borne peculiar optical properties. If we look any thickness of a coloured mass it is purely yellow, but if we look at any surface of it npon which the light falls it appears green. This phenomenon ia possessed by uranium glass, in common with a solution of sulphate of quinine, an infusion of horse-chestnut bark, and some varieties of fiuor-apar. The investigation of this peculiar dichroism was first entered on by Sir John Hersohel, who observed that the cS'ect was confined to the first surface of the body, and hence he spoke of it as epipoittni; but the thorough examination of the subject was reserved for Professor Stokea, who shows that the rays thus rendered visible to ua do not belong to the ordinary prismatic spectctua, bBN\ii%i.

mm

muoh highev degree of refrangibility than any of the Newtoniaa rays. To diHtinguiBh those rftja ProfesBor Stokes proposed, aa they are very beautifully ehowm by Baor-spar, to gn-e -ti"-" "f fiuuretcent rays.

Jiiy at>d Olast. — The meat reds on tho v dnced by the jirp?8 o/'Cassiae, which may be regarded as a rtanuate of tin with a BtMUlate of oxide of gold; or by a solDtion of gold agtta ragia {mtrokydroekhiic aeiil).

The Bohemian ruby is thus prepiB'Qd : — a, prepttration called schmelze is mode ; it is cooipoaed of siliea 500, minium 800, niti 100, calcined potash 100. Tha gold eolation contains 155 grains t gold in a quart of aqua regis, which is then mised with five times ita bulk of water ; of this gold solution is mixed intimately with SIS paa of Bohmelse, 48 of borws, 3 o£ oxide of tin, and 3 of oxide of antimony, all in a state of fiae powder. The whole ia then heated, for 12 or l-i honrB in on open crucible placed ia a glasa furnace, and then Butfered to cool in an annealing oven.

Tho ordinary red glaaa is produced by copper. The aub-oside of copper posseBsea a colouring power of remarkable intensity, the smallest quantity reddening glass so deeply as to render it almoat opaque — hence glaoa JB nsuallj' only coated or flashed with the red glass produced fy the aub-oxide of oopper. Glaas containing sub- oxide of copper dooanot exhibit its colour on leaving the crucible; it is, in the first inatanee, neajly colourloea, with a slight tinge of green, but it beoomea deep red when, after having cooled, it iB heated a second time at a lower temperature. H. Rose supposed thia curious ptenouienon to be due to tho formation of an acia or neutral silicate at a high temperature, and that the Bubseauent softening at a low temper&tm'B cansea the decomposition of this compound, and a aeparation of some sub-oxide of copper wtich colours the glass.

Many examples oTjlaehmg, at spreading one oolonr upon another over white glass, are in the case. By cutting down through those layers to different depths, a very omamoiitsl appearance can be produced. (See oteo Case 56, where the process or cutting is illua- trated).

Some common red glaas is produced byii'on-

Amelhystin Glase is produced by the poroxidef manganese.

is obtained by the protoxide of iron, bnt a finer colour by theoside of copper. Glass, coloured green by oxide of copper, has a remarkable power in stepping back the solai' heat-rays. Mel-

loni found that an apple-green oopper glnaa, made in Italy jprevented the permeation of at least 80 per cent, of the heat-rajs. The author of this Guide discovered that the smalloat quantity of the oxide of copper, in glass free from manganese, possessed the property of stopping all the paraOiermic rays ; these are rays of low refrangi- bility, found below tho red rays of tho Mewtonian spectrum. "'- these heat-rays the scorching or plants is especially due.

Glass prepared by Messrs. Chance, Brothers, upon thia principle has been employed in glazing the great palm-house in the Eoyal Botanical Gardens at l£ew with the most Batisfaetory result. It baa been observed that greenboiiBes gazed with the Old green crown- glass are more favourable to vegi'tation than such as are glazed with the mora agreeable while sheet-glfla,

Blve Gias.— Oxide of cobalt is used for producing the fine bluef which wo see in flint glass. One thousaudth part of cobalt will giv< a very deep bine to glaBs, and one twenty thousandth will impart t F-prj'pcToeptihle tint. Tho preparation of Binalta or mJfr6hBS been dsoi-ibed. (Seep. 114).

Glass. 1G3

Threaded Glass. — This is prepajred in the manner noticed under "Venetian glass (p. 160).

Millefiore. — Examples of these modem imitations of, and improTO- ments on, the old Venetian are shown ; and a specimen exhiLitiJog the manner in which the sections of canes are disposed previously to their being enclosed in a mass of transparent glass, accompanies the specimens.

It will bo evident, that having once enclosed these coloured canes in a mass of glass, it can be readily formed into tazze or vases, as shown in the finished examples in Case 68.

Engraved Glass. — Some very fine si)ecimens are shown, especially in Case 69. The ordinary tools used in engraving glass are discs of copper, some as large as a halfpenny, and others mere copper pencils which are moved by a lathe ; these tools are smeared with oil and emery. The hard grains of the polishing material penetrate the mass of the soft metal during the process, and form a species of file, which in revolving cuts into the softer glass.

Aventurine Glass. Case 63. See also Venetian examples and ITo. 596 in Horse-shoe Case. — This is an ordinary glass, which owes its colour to the sub-oxide of copper ; and the brilliant laminae are probably metallic particles, produced by the addition of some power- ful reducing agent to the melted copper glass.

Abtificial Gems. Case 69. — S trass, so called after its inventor, is a glass possessing in the highest degree purity and transparency, combined with the greatest possible lustre. It is a mixture of quartz, boracic acid, purified caustic potash , and a large proportion of oxide of lead, introduced in some specimens of strass as red lead, and in others as white lead. With perfectly pure and colourless strass, the colouring agent is combined — the following being a few examples: —

Topaz, antimony and gold; Buby, purple of Cassius; E'tneraLd, oxide of copper or chromium ; Sapphire, oxide of cobalt ; Ainethyst, cobalt and gold ; Beryl, antimony and oxide of cobalt -, Garnet, gold, antimony, and manganese ; Opal, bone ashes, oxide of uranium, and forge scales, or, in some cases, oxide of nickel. — (Knapp.)

Artipicial Pearls. Case 69. — At an early jjeriod the practice of making hollow glass beads, and filling them with a pearly varnish, was adopted. Beads were thus made by some artists at Murano, but the government of Venice considered the invention too fraudulent, and prohibited its practice.

A French bead maker, Jaquiu, revived and improved the art. He observed that the small fih called in France ahlette — the bleak, Gyprinus albumus — filled water in which they were washed with fine silver-coloured particles. The water on standing deposited a sedi- ment which had the lustre of the most beautiful pearls ; this led him to attempt the manufacture of pearls from it. He scraped off the scales ot the fish, and called the pearly powder which was difinsed through the water, essence d' orient, or essence of pearl. He fiirst covered beads made of gypsum with this ; but as the ladies who wore them found the pearly powder left the beads, and adhered to the skin, the use of those ornaments fell ofi*. The beads were then made of glass— a glass easily melted and made a little bluish, being drawn into tubes, which were called girasols (the word signifying opal). From these tubes hollow globules were blown, and they were then covered on the inside with a solution of isinglass and the pearl essence, which was blown in warm and spread over the inter- nal surface by rapid motion. When dry, the globules were filled

w

Ths Prdtcifax Floob.

beads cue atoll raaAa of all shapes and eizes, and many of the most perfect iraitationa are sold at good prices. The bleak ia a flat of abont foTiT inches long, caaght only in freeli. water ; to obtain a pound of Bcales, 4,000 fish are necessary, and those do not prodnce fonr ouncee of pearl essence, to preserve which sal ammoniac in eolution is nsed. The optical effect is produced in the same mannor as in the real pcai'l, the grooves of the pearl being represented by the ineqnaUties of the lamina formed bj those pai'tioles removed from the soalcB of the fish.

Enamels. TiAle-caiei 60 and 61. Model of Tomh No~ 59.

Enamelling, or the process of covering metsJa or etones wit vitreoiiB substance, or of mnning enamels into portions which have been previously removed by a. graver, is of high antiquity. There was but a step from the enamelled bricks of Babylon to the enamelled bronzes of the Romans, or the shrine enamels of the BjaantinB empire.

A series of nistorical specimens illnstrating this art will be found in Table-case 61. Commencing with some Eoman enamels found near Eden in Cumberland, we have next a Byzantine enamel on gold of the century, being a portion of the "gold altar" front obtained &om Constantinople by the Doge Fietro Orseola. This ia followed by a reliquary of the 13th century, enamelled iu the style called c/iamp iete. These shriiiea or reliquaries were in comn

use, and were uauallv decorated with, some legend of the as.

to whom they were dedicated. In the champ-ieve proceaa those parts of the design intended to appear in enamel are hollowed out in the metal ground, leaving the outline in slender elevated parti- tions, or bands of metal; the intaglio portions are then filled in with the coloured vitreous substance introduced in the state of powder and afterwarda fused ; tho surface of the whole being finally smoothed by grinding and polishing.

In the 14th century we Lave a priket candlestick from Dijon in ehamp-levS enamel, and a monslj-ance ornamented in a difleront style of enamelling, the design being here chased upon a silver plate, and the surface then covered with brilliant transparent enamels, through which the design appears. The 16th century is represented by an entuaelled processional crucifix from Italy, and from thia we pass to the much admired Limoges enamels of the 16th century. These are painted enamels of considei-able merit, usually executed en grisaille on a dark groimd, and relieved by the intro- duction of fleiih tints and touches of gold : the works of the later artists are however frequently coloured, as seen in the polychrome enamels of the 17th century here eshibited. From the paiuting of enamel pictures, the art was extended to the decoration of metallic vaaeB and other ornamental objects, of which the enamelled taaza in this case is an example. Among the Limogea enamels uill be fonnd works by Limousm, Eayraoud, Nouaillier, Laudin, and the master I. M. From the coloured enamels of Limoges we advance to what may be termed the enamel painting of modern times.

Enatnel painting — -proiierliy, paiuting on enamel — ia fully illus- trated iu CixBe 60. The white cake enamel used an the painting Sound, and the beads and pipe employed as a flux, are oil manu- 'tared in Venice, These appear to consist of about ten paits of Jead and three parts of tin, converted into Ds.\de by heat and expo- sure. To the mixed oxides arc added ten poiVa ot im\.'i.

EffAMraS Aim" MOSAICS. 185

psrta of coinmon salt, and the whole faecA together. The oimmcl being reduced to powder, is spread over a plate of copper or gold and exposed to a strong heat; the enamelled plate ia then coated trith flux, and acaia fired and ground down, as ubown in the gpeei- mens. This is the surrace upon which the enameller has to norlc. He takes metallic oxides, these he mixes with the flux and paints Ilia picluTc. An enamel painting haa to pass many times throagli the fire, CDnfiequentl}' great care is required in this port of the

Ko fanlt can he corrected, the fire fixes the colonrs aa applied, and whether good or had they are unchangeahle. The Tarious coloors employed are shown.

Mr, Hone was probably the first who ventured to paint large enamels ; a small work by this artist, of the date 1749, is in this case. Mr, H. Bone, R.A., by whom there are several bcantiful works, exceeded all before him in the size of enamel paintings, his Bacchus and Ariadne, the original of which is in the National Gallery, measnring 18 inches by l(?i. The portrait of Sir Henry De la Beche was painted on enamel from the life by Mr. H. P. Bone, and presented by him to the Museum -. this, from the difficulties of Ibe art, is not often attempted. There are other examples by the same artist.

The modern French Limoges enamels, and another, together with the portrait of the celebrated Sanssure, by Constantin, painted in 1815, will show the state of this art on the Continent.

Modd of the Tomb of WilHam ile Valkiico (No. 59).— William da Vallenco, senior Earl of Pembroke, half brother to Henry III., died in 1304, and was buried in Westminster Abbey. His tomb waB decorated in the costly style of the ieriod. Not only were the portions of the original enamelled, which ore copied in the model, but that part also which ia here represented in woodanpears to have been covered over with brass plates riably enamelled. This ia in- tended as an illustration of the history of the applications of enamel to the decoration of tombs. The figure is of brass, cast by Mr, Bealtie, and gilt by the electrotype process ; the eiiamoUing by Robert Aiager, and the base of Oaon stone by H. C. Smith, con- structed under the superintendence of the lute Albert Way, Esq., F.8.A.

Chineie EnameU, Olass. Sfc—Io Caee 53, on the eastern aide, will be found some specimens illustrating the art of enamelling amongst the Chinese. Prom a very early period this nation has been in tbe poaseasion of the art of enamelling metals, and of painting on enamelled surfaces. The large plaque and the howl are examples of ancient duisojme enamelling, dill'ering Irota the champ-lev pro- oeBB already described, inasmuch as the outline is here formed, not of the plate itself, bnt of separate narrow bands of metal bent into the required shape, and attached to the ground. These inomsted enamels arc accompanied by several examples of superficial enamel- ling; and with these are associated various specimens of Chinese pottery and glass in course of arrangement.

MosMCs. Tiible-ettae 54 Portrait of the Emperor of Bussia, &o,, on giillery stairs, eastern

side. Head of Christ, &c., on western side. In noticing the tesselated pavement in the lower ball, the pave- ments of Wood cheater and of Cirencester \).B.e o.\Tea4\ifte\VMMais&_ in tbia ease are examples of ancionb B,omaTV \e4iie\M4 "jw'a.'Sisa.a,

Icc Model Rooms.

which show the mauner in which they were eonntmcted, and the kind of design whioh ia uaually found. Many of tlioee Eoman paTB- ments are not only interesting as relics of this groat people, but they are heautifnl works of art, and they must have been the reanlt of immense labour and great shill. A portion of a mosaic pavement found at Halieamassus is monntod on tne W. staircase.

The art of numufactnrin gloss mosaics was practised in old Kome, and the modern city is still the seat of this mannfactnre. The raanufactare has, however, as might be expected, varied some- what in character. Ab at present practised, thin rods of easily fusible glaas of every variety cf colour are prepared for the pnrpOBe. From maflses of coloured glass are formed, first, slabs, and then the little rods exhibitodj the artist softens these in the flame of his lamp, draws out the rod into a thick thread, and breaks off a piece of the thickness of the intended picture. The design of the picture is copied from a cartoon, and the pieces are placed in proper order cm a sheet of copper, covered with a cement which serves for fixing the picture ; when the whole slab is covered, the surface, which is uneven and unsightly from the unec]ital lengths of the rods, is ground and polished. Alter the removal of the polishing powder the inter- stiees between the rods are filled with was, which coireaponds in colour with the different parts of the picture. Some large esamples of modem mosaic work are near the gloss on the eaet aide. The largest known m-osnic pictnre is taken ii-om the Lord's Sapper of Leonardo da Vinci, which is 12 feet high, and twice as long; it is said to have occupied eight or ten artists daily during eight years. The Byzantine mosaics differ from the others only in the artistic character of the productions. A larger example of this -work is the Head of Christ, on the western staircaeo ; whilst on the opposite side are two modeaai mosaics, of large size, one the jtortrait of the late Emperor of Eussia, executed in 1828, and presented to the Museum by the Oavaliere Barbieri.

The opas twcerfiwn (TerrsKO or Paviraento Teneziani) ia in com- mon use in the north of Italy for floors, the colours being given to the lime by ochres. The lime ash floor of England is another 'variety ' of the same composition.

The pieces from the walls of Pompeii show the kind of stucco used, and the general character of the paiutinga i;i the boasea of that oiiy. It will be seen that these are not in fresco, bub ordinary paintings on the cement employed.

The Model Booms.

In the very limited nnmlier of pages which can be appropriated to a notice of the ohjccts in this section of the Musenm, it is impossible to introduce SJiything beyond the most brief descriptions : this, how- ever, ia the less to be regretted, since a special catalogae of tiiis department has been prepared hy Mr. Baueiman, to whose des- caiptions the visitor seeking farther information is in all cases referred.

The Model Booms are situated at the northern or Piccadilly end of

the bnilding, and comprise an eastern and a westerji room oi the

prJnojpal Sooi, marked reepectively A and B ; with a small supple-

iBQntary apartment, C, approached from the lower gallery. As

theee roQzoa ai'e not ni'OTJded with gas, btc ntteaaaiUy closed

dask.

MODEIi ROOKS. 167

On the right-h&nd side of the entrance to the eoBtem room (A) ia a, model illastratia);; the plan adopted to condvHt Uad /umee at tJia Wanhek Head Works, in Clydesdale (p. 65). Flat aaid rownd ekaina far mining purposes are fixed on. each side of the doorwa;, and in front of these are three models of different forms of the numengiiis, — a German invention for facilitating the descent and ascent of minera. It was originally introdnced in the Hartz in 1833 ; the large model on the right hand regresenta one erected at Fowej Oonsola in CorawftU in 1851, It will be seen that in acme of the forma the engine has bat one rod and therefore one periee of platforms, whilst Others are famished with a double rod. Immediately on entering the room will bo found, on the left-hand wall, a sectional mfidel of the li-orkmgao/ Dokoatk Mine, BOOT CaaboTae(il. 4,)~oiie of the oldeet, if not the very oldest, of the exieting mines in Cornwall. The red wood in the model repreaenta granila. and the whito the killHB or Cornish day slate i the lodo being ebown by the black layer which extends orer both these roeka. It should be understood at the spectator is to Buppoeo the granite and elat aro entirely removed from the ude of the lode Dearest to him. and that he looks upon a veHdoat BBction of the lode, and the workings bj srhich the metalliferous portione have been removed. The description of this model in the emiier editions of the Gaide baa been transferred to the Catalogue ofModels. A (xe of eafely fusee and earlriJgee is placed iibove the model of Dolcoath. The table at this end of the room is occupied by models of various forms of iiTinu, or machines for raising minerals inmine'Sharts.

A large and very perfect working model of TtujJor'g engine (H. 5) at the United Mines, in Gwennap, occupies a prominent position in the centre of the room. The oelebraiod Cornish pumping engine, of which this is a model, performod the high daty of lifting one hun- dred and tea milliona of pounds one foot high bj the consumptioa of a single bnshel of coal (94 lbs.) in the repkioe of the boilers.

On the tabic on the right-hand side of the entrance will be found a model of a Welsh blast fitrwKe and hloi:-ing maehhte (N. 24). The air from the cylinder of the blast engine before entering the famaee flows through the regulator — i-epresented the large copper sphere — and, when the hot blast is employed, Ukewise passea through a system of heated cast-iron pipes, the arrangement of which is also shown in the model. The remainder of the table-space is occupied by a model of a doubt-cylhider blast-engine, used at the Royal Saxon &nelting Works, on theMulde. Paasingoverthemodelaof pumping engines on this side of the room, we reach the large model of a water freasure engine at tlie Alport mines, Derbyshire {H. 4). This model, when viewed from below, shows the shaft in which the pumpa are placed by which the water ia drawn from the mine. Above ia the tube for the column of water, by the pressure of which the machine is moved. At the Alport mines and mil level or is driven to flie mines from the banks of the river Derwent, a distance of three nriles, 80 as to drain the mines to the depth of about 22 fathoms j id tho water from ±he workin;a Ijolow this level is raised by three large hydraulic engines, of which the most successful was Uie one hero represented, constructed at the Butterley Works from the designs of Mr. Barlington.

Opposite to this model is a small sUme hreaJcor made on BWce'a principle by Me.srs. Marsdeu of Leeds. Machines .of this kind now largely used for crushing oro as well as for breaking stone for nd metal. A stand of wire ropes is fixed. e.\y3a ya *\*.,'-;ai- fiontofn-iici stands a Oomiah enwftmgmaclvvive'Qai*i.*'**' of copper ore. At this end of the room -witt. 'ViB iouni ws>iwl>. asar

168 Model Hooms

trations o? boring machinei'!/, the Hnrface ari'angementa Ijemg repre- sented by model 0. 21, while the fools actually employed are iDOnnted near the epirsl Btaii'co.ss. On the left-hand side of tha fireplace atanda & large model (C. 22) of two forms of boring appa- mtua with free-fulliDg cutters adapted for deep borings, uloaa to this is a model of a waler wheel which represents one of a pair employed at the Devon Great Oonsolidated Minea. These mines consist of Huel Marin, Huel Fanny, Hue! Anna Maria, Hiiel Joaiah, and Huel Emma. They are eitnatcd on one of the hanks of the river Tamar, near Tavistock, among most beantifally-wooded hills. The wheels are worked by a stream of water taken from the river at a higher level. One sot of wheels ia employed in di'aining the mine, and another for Bending water over the hill to supply the di-essing floor of the mine,

HexC to the mode! of the Devon Consols wheel is a model of n Btmiiar vertical water wheel used for pumping at "Wheal Priendahip, near Tavistock. On the metal table opposite, in the centre of the room, stands a model of the twhine orhorkonlfd water taheel {H, 3) on Ponraeyron's principle.

Along the northern wall is a series of cases containing tooU em- ployed in variotts mining distriels ; and by examining these the miner of any one country or district at once becomes acquainted with the description of tools employed in another. Sear the entrance to Eoom B. is a case devoted to tools employed by the colliers in the North of England. Close to this stands a case of tools used by the metal mineia of Cornwall, and including also some specimens show- ing the structure of different forms of safdij-faae. Hero also will be fonnd some samples of e?Bc(n'c/uBes, and on the lower shelves a few ancient mini'ng tools. The next case ia appropriated to Sason tools, and the succeeding case to the tools used in the lead mines of Derbyshire and Flintshire. These are followed by a case of Mexican tools, and these in tui'n by examples of tools employed in the col- lieries of South Wales, Then follows a case containing miningtciols used in Flintshire, and also a set of Russian tools. Finally, there is a case devoted to the tools used at Schemnitz, in Hungary, where the mines yield ores of gold, silver, lead and copper,

Leaving the eastern model room, the Tiaitor enters the second apartment (B.), which is devoted chiefly to JLlustrations of colliery workings. On the left side of the entrance, however, there ia a model of Jordan's pwnpi irUh rode of wire roie. Immediately facing the entrance we find a model (A. 19) representing the physical fealwres of a caal dittriel, showing the outcrop of the beds of coal, and how they are affected by faults or troubles. On the right side of the visitor on entrance is a model (&. 3) illuati'ating different methods oi working ojmZ venlilating coalmines, which are sufficiently explained by the accompanying descriptive label. Nest to this stands a model of the Foreet of Dean (A. l-i) by Mr. Thomas Sopwith. It represents a tract of country comprising the principal ooal-field of the Dean Forest, the superficial area being 24 square miles. The oulcTOpB or basseiiTtg of tbe principal beds of coal are shown on the surface, and vortical sections of tbe strata are painted on the sides of the model. In order to show similar vertical sections in the interior of the Forest, the model is made in compartments, placed on a sliding table, so as to be easily separated.*

' It is important, to avoid injury, (hat the models should not be louoheil, eice/iriyjiersonsacqlisinled withthem, 'Foi any specinl purposes, permission to emtaine this and other models minntelynlttj ba oWaaiBS.nn. llie public are - especiai/ff reqaeslcd tiol lo attempt to OJJin the. iiiodela.

Uodel Boohs.

fnane by Mr. W, H. Jordan. The drawing ropes, proceeding if . . the in tUe engine honae, pase over the guide rollers at tho top of the shear frame, and are attached to the cages, or covered plat- forms, mnning on guide rods, nnd provided with sftfety catches. Behind the pit frame stands a model of Ehbw Vale and Strftoioj Iron Workt in the coviU'j of Monmouth (A. 13). This model is by Mr. Sopwith ; it aompnaes nearly four square miles of ground. The upper surface bemg taken off, the black-pine mine, a vein of iron- Btone, with the workings in it, appear. Below this the three-qaaiier eoal, modelling coal, and red vein mine are exhibited by removing successive trays which represent the intervening strata.

In front of the fireplace is one of Bidlei/ Vo.'s eoal outting maekinea, worked by compressed air. This machine, which has been introduced into several collieries, is intended to supersede manual labour in undercutting or " holing " in coal. By the side of this is an example of Meere. Jonea and Bidder's appaTotue for gwperteding awtptnoder in collieries. A hole is first bored in the face of tte ooal by means of the spiral drill, and a steel cylinder in two parts is then introdaced into the hole ; steel wedges are afterwards inserted between the parts of the wedge and forced in by hydraulic power ; they thus escort pressure in all directions, and the coal is conse- (piently broken mechanically as it would be if gunpowder had been employed, whilst the danger of firing a shot in the explosive atmos- phere of a mine is completely avoided.

Over the fireplace is a large screen bearing a of ancienl proceamaiiol tools from Saiony. It ia interesting to note how the several parts of a timberman's ase have become conventionalized and rendered useless in these ornamental tools. On the right side of the fireplace arc two natural sections, one of the coal seams near Bamsley, the other of ironstone deposita in North Lincolnshire.

At the end of the room are two large models of Shipley Colliery, in, DerbyehifB {G. 1 and 2), presented by Mossrs, Woodhouse and Jeffoock. From these accurate models ah excellent idea may bo ob- tained, not only of the most approved surface arrangementfl of a large colliery, but also of the undergroand workings. O. 1 shows the method of working the ooal and the course of the ventilating Durrents, whilst G. 2 exhibits the winding macliinery at the surface, with its steam engine, &c. Near G. 1, and occupying the greater part of one side of the room, is a large model (F. 52) of a aelf-aeting metined plane at the TJpleatham iron miaea, in the Cleveland district of Yorkshire. The ironstone, which is obtained from the marl- stone or middle lias, is brought from the mine in small waggons uid emptied at the tipping cages into larger waggons. The train of loaded tracks is lowered down the inclined plane by the dmm, whilst a train of empty waggons is being drawn np. At tho back of thia model, against the adjacent wall, is a natural section of the eoal

meatvres at Ike Bosehridge vUs near Wigan. The Eosebridge colliery hae reached a depth of 815 yards, and is notable as Doing the deepest in this country. By the side of this section is a flee specimen of Sie Better-bed coal of Bradford in Yorkshire. The specimen ex- hibits a section of the entire thickness of the bed, and shows the character of the adjacent strata. The " better-bed" coal is interest- ing for exhibiting under the microscope vast numbers of tho spores of coal-measure plants. TTnder the model G. 3 is a sampU of the Brora eoal worked to a limited extent in the Oolitio rocks of Sutherland, whilst a sample of Indian coal from the B.iniigafig,e oiiB,\.-&a\4.*iom.

170 uossa naftttsr

andor an adjacent case. On the wall Ijeneath tte windowa of this room is a aeries of glaaa-Cftsea containing a collection of cages and Kity sidffs, among which will bo found illustrations of several recent inTBntions. In moat of these contrivances it is a,rranged that npoa the breaking or cutting of the rope the cage or bucket ahall be gradually or sniidenlj light to rest bj being wedged against the guides in which it travela.

Betnrning to the eaatera model room, and ascending the spiral Htftircase at the S.E. corner, the visitor reaohea the eaetern end of the gallery leading to the third model room, C. On tlie north eide of this apartment ia a large German model (M. 6) illustrating tho various tnining and drtevng ojiercUiona as co'tiduoted in the Sajon lead miMes at the close of the last century ; and in the centre of the room Btanda a model repreaeating the gv,rface inorkinga of a eniatt CarmUh fin mine [U. 3). Here will also be fonnd a number of modela illna- trating varioua modes of supporting the ground in mining excava- tions by Umbennfj and inmimify, and of protecting wet colliery shafts by eaeUi/ron iiAhing. In front of tho fireplace ia a small hand oruaher, employed in some of the Derbyshire lead mines ; and on the aholves in the BOnth-eaHt comer of the i-oom is a aeries ai geological modals by Mr. Sopwith, whose descriptions of them have been transferred to the Catalogue of Models.

Pesaing from this apartment to tho gallery of the model rooma, we find at the head of the stairoaae a model of a crane need for eliipping large blocks of eandatoiie at tho Eedhall quarry, near Edin- burgh (F. 53). On the adjacent table atands a model of a lead ebavtier for confnaatton of sulphuric acid vapour, produced by the oxidation of eulphnroua acid {S. 35) ; and the reverleralory fumace at the side (N. 36) ia designed for the prodnotion of siphate of soda by the action of sulphnric aicid on common salt, the sulphate being afterwards converted into aoda-ash. The nest model (N. 34) represents Mr. Tov/ng'a a,ppaa-aktS for ike manufaotm-e of itennote of tcda, a salt . prepared by the reaction of tin-stone and caustic soda ; and this is followed by a model (N". 15) illustrating FattiMBon't proeees for desilimring lead, which baa been described at p. 116. The remainder of the table-space in this gallery is occupied by models representing several forms of blast fvmiico, some of which 9.16 provided with arrangements for utilising the waste gasea from the top of the furnace.

Ibe four wall-cases in this gallery aro appropriated to inodek of mctallv/rgical fii/macee, distribnlyed as follows: — in Case 1 are several Saxon furnaces for lead smelting, with a Belgian zinc, and a Coruiah tin-furnace ; Caae 2 contains the apparatus employed in the Sason proceBseB for silver extraction ; the next, Case 3, is devoted to iron hmittcCB, including a model of Whitwell's hot-blaat fire-brick stove j ajid the last. Case 4, contains models of North of JEngland lead- hearth, with a model illustrating Siemen's process of making steol, acd one of Siemen's regenerative gas furnaces, &c. In the regenera- tive furnace the heat is obtained from combustible gases (carbonic oxide and hydrogen), which are produced in the " generator," and are heated prior to combustion by passing through a mass of brick- work which has been heated by tho products of previous combustion.

At the western end of this gallery is a glass case filled with a large aeries of erysialhgTaphic madeU in wood and glass; while larger models adapted for the lecture table will be found ou the Upper sholvee of the wall-caaes in the large room on the ground

Lower Gallery. 171

Occupying the table-space in the wcstom gallery arc illnstrations of seyeral plans for ventilating mines, together with modclfl of huddles, jigging frames, and other dressing machinery.

Commencing at the entrance to this gallery, the first Wall-case No. 5, presents a large display of mining lamps among which the safety or Davy lamp for coal mines merits especial notice.

It will be seen that this is a lamp snrrounaed by wire ganse. The principles of its construction, arrived at by Sir Humphry Davy, by a very beautiful series of inductive researches into the character of flame, are the following: — Gas, in a state of combustion, will not pass through fine apertures. Hold a piece of wire gauze above a gas flame ; it will be found that the flame will not permeate the ganze although all the gaseous products of combustion pass it with great facility. The light carburetted hydrogen gas, formed by changes taking place in the bed of coal, forms, when mixed with air, an explosive mixture, which is far too frequently of tlie most de- structive nature. This gas passes freely through the wire gauze into the flame, and it is ignited within the lamp ; but as the flame cannot pass out, no explosion takes place on the outside of the wire. When the carburettea hydrogen gas becomes in excess, the light of the lamp is extinguished. The miners complain of the deftciency of light from the original Davy, and hence various improvements have been introduced, of which several are here exhibited. Among the most recent may be mentioned Crag and Bidder's magnetic lamp, which when locked cannot be opened except by ])lacing the lamp on a powerful magnet, when the iron bolt is withdrawn by attraction.

Among the objects in the next case are several forms of pyrometer, or instruments for measuring higher temperatures than those capable of being recorded by ordinarv thermometers. The most noteworthy of these is the ingenious electrical pyrometer devised by Mr. Sietnens.

Passing over the wi/ndlasses and ventilating machines in this case, we findwe next section appropriated to Oay Lttssac's apparatus for ct9fiwying silver hy ihe wet way, that is, by precipitating the silver aa chlotride by the action of a solution of common salt, a method first adopted at the French mint. The remaining wall-cases in this gaUlery — the arrangement of which is not yet completed — contain models of dressing machinery, described in detail in the special Catalogue of Models.

The Lower Galleey.

THE PALiEONTOLOGICAL COLLECTION.,

The two galleries, with the exception of the recesses in the upper

fiUery, are devoted to the illustration of the Fossil Geology of the ritish Isles. In this Guide it will not be necessary to do more flian indicate the general order of arrangement, and to point to the larger groups ; referring for further information to the Catalogue of tib CoUection of Fossils, which, in addition to a complete inventory of specimens, contains a valuable sketch, by Professor Huxley, of the general principles of natural history and their application to the elucidation of Fossils or Palaeontology. .

172 Lower Oallert.

diaconrse or doctrine. Th.o palseontologiat, therefore, seekB to learn the order in which the forma of life have been developed, and he endeavours to make eafe deductions from tbo disooveriea of the geologiatj by which he may advance eoiontific truth, and thus neces- sarily increase its powers of practical apphoation.

The diviaioQB which have been adopted for the purposes of group- ing together rocks with especial roftrenoe to their' organic remains are as follow: —

{Lam*entian. Cambrinn. Lower Silurian. Upper Silurian. jriimu,.j' r Devonian.— Old Eed Sandstone.

TT -o 1™, J Lower Carboniferona.

L Permian.

ITriassic, — New Red Sandstone. Lower Oolite. JSKddl.dillo. Upper ditto, rr ir i Lower Cretaceous.

r Lower Eocene. TBocenet - - Middle ditto. I Upper ditto. Tertiary Meiocene.t

PleioceneJ - Poat-tertiary.

Thia table commences with the oldest known sedimentary roots (the Lanrentian), and, neglecting minor euhdi visions, proceeds thence in a regularly ascending scale. In arrangia IJie foBBils a similar plan baa been adopted. The foaails are ex&bited partly in the BTat-casea and partly in the Wall-cases, whilst a large number of apecimena are placed in the drawers beneath the Flat-cases. In the following description the Flat-caaea are distinguiahed hj nnmbera in thinlpe(l), and the Wall-cases by thick type (1). In esamining the Wall-cases it should be noticed that the numbering, unlike that of the minerals and rock-specimens, proceeds from the hwer part of the cases, the bottom shelf being al vays regarded aa the first.

PiLaozoic Fossils. In the first of lli£ FlaL-aaeea on the left-hand or western side of the gallery (1), and in the lower part of Wall-casea, aectiona 12 and 13, will bo found the earliest indicationa of foaail remains which have yet -been discovered in the lowest of the JPaliBozoia rocks, or those in which the indications of the most ancimt li/e appear, — with the exception only of the Eozoiiit, detected in the Iiaurentian rocks of Canada, Bohemia, Savaria, and elsewhere (p. 72). There mre in the Carabrian rocks near Dubliti two apeoiea of branched or plant- like organiaras, probably Zoophytes, called OMAamia. In ro of

The middle forms of life, txlaos, middle, faij, life, f The dawn of recent life, i/lb!, ihe daum, Koitis, rc(:et. t The less recent life, n'lwv, leas, Ki.vb!, tcpctK.

Uie same age in Shropshire, known us the Loagmynd beds, there are traces of worm-like animala (anticliiU), and a solitary trilobite, or irliBtappearB tobeench; whilst many otbcrtrilobiteeliave been found ia the Harlech grits of St. David's. Foasils beoomo inoro numerous and varied when wo ascend to that zone which has been termed by Mr. Hiolts the Menevian heda, and which wae formerly olasaed with the Lingiila Flags. Theae Lingola beds derive their name from a sinaU ahell calledthe Linc/ula, while the Menevian beds borrow their deaignation from " Menevia," the clasaical name of 8t. David'e. Among the Menevian fossils may be specinily mentioned the large trilobite known as Paradoxuleg. The trilobitea were crne- taceons, or creatures remotely allied to the crabs and lobaters, but different from any craataceans at present living. Many of the apecics were capable of rolling theraaclvea up into a ball, like the common wood-lonse, and many examples of these rolled-up trilobitea will be found in the collection. I'he Lingula flaga are followed by the Tremadoc beds, so named from the locality in North Wales where they are charactcriatioally developed ; and these in turn are snoceeded by the Llandeilo flags, which take their name from a looaliW in Carmarthenshire. The fossila of the Lingula, Tremadoc, and Lumdeilo beds are arranged in Flat-cases I to 3, and in Wall- cases, sections 12 to 13. In the wall-cases will be found numerous examples of the curiously serrated creatures called Graplolitcs by Linnteus, — ypi-pu, grapho, lyn'ite, and X/eot, Uthoi, a stone, — from the resemblance of their remains in the stone to writing or sculpture. These graptolitee are extremely characteristic of the Lower Paleozoic strata, ana are abundant in the Llandeilo and other Lower Silurian rooks. Flat-cases 4 to 11, and Wall-coseii, sections 14 to 16, are deToted to fossils ',from the Caradoc or Bala heda. The former name is taken from Caor Caradoc, in Shropshire, where shelly sand- stones of this age occur ; whilst the latter name is borrowed ftum Eala, in Merionethshire, whore a fossiliferous limestone is found of approximately the same age oa iho Salopian eandstones. The Bala limestone has yielded a fine suite of fossils, including numerous trilohites, star-flshes, and molluaca. Among the mollusca, or " shell- fish," the moat notable forms are those known to naturalists as Braeldopods, the characteristics of which have been already pointed out (p. 31),

Above these Bala beds occur the rocks which are named after the town of Llandovery in South Wales, and which are divisible into a lower and an upper group. The Lower Llandovery fossils will be fotmd in Flat. cases 12 and 13, and tlie Upper Llandovery inNos. 13 tol5i whilst both upper and lower are distributed through Wall- eoBBS, sections 17 to 18. The classification of these beds is a matter of some difficulty ; the Lower LlandoveTT, however, are placed by the Bnrvey in the Lower Silurian series, while the Upper Llandovery beds form the base of the Upper Silurian group. Succeeding the Upper Llandovery rocks we ha\-e tbe Woolhope beds, whose fossils are exhibited in Plat-casos 15 and 16 ; then the Wenlock shales, repre- sented by fossils in Cases 18 to 18 ; and above these, the Wenlock limestone which has yielded the fine series of fossils in Cases 19 to 25. The Woolhope and Wenlock apecimena are continued in the Wall- caaee, sections 17 to 24. By far the greater number of the fosaila in this series have been obtained from the Wenlock limestono, which forms a coiiapicuous ridge in Shropshire, and is often known as the Dudley limestone. The trilobitcs are extremely abnndant in this for- mation, one of the moat Q,ojaTao-D{Ci.hjmeneBlii,'Menha,chiii being known to collectorH ajj the "Dudley locust." Attc\rt\on. loa.-

drawn to the remni'kably fine example of the trilobite called E hiiohfs ddphinoafpbahis. Nor should the romarliable eiampl crinoidB, or sioaa lilies, CBcape attention (p. 30) ; whilst the cork are repreBcnted by a laa-ga nomber of epeoiea as the weU-knotfll " chain coral " {Halyaitea caieiiularkis). Oontinuing the eiaminatiop of the riat-cases the visitor finds in Noa, 23 and 24 the foasilH of the' Lower Ludlow, and in 26 to 28 thosB of the Upper Lndlow rockaj tbo intermediate Caeo, No. 25, being occupied by the foaaila of thp, JTneatry limestone, among which the obaracteriBtio Penla/mentB iijMil ifl especially couspicuouH. The Ludlow series is continued in Wall-coBee, eeobaQs 25 to 37, whilst the Bncoeeding sections 28 and 39 are devoted to large speeimeos of Upper Silurian Cruatacea (ftnimals with a crust-like covering, aiich as we see in crabs and lobatera), amoug which may be remarked especially the remaiiiB of .the great Plei'ygotia, a crnstacean six or seven feet long. In the next BBction, 30, will be found remains of some of the oldest flafaoa known, — Pteraspie, Onchua, &c,, — from the "Ludlow lione bed," which occurs just beneath the Downton sandstone; and from the beds, formerly tailed tileatoneB, and considered to be the base of the Old Bed Sandstone, but now claased with the UppermoBt Ludloiir roek, and aa beds of paasage to the Devonian rocks. It should b6 lemarked, however, that the remains of fish have been found in the Lower Ludlow rocks, and that these are at the present time the oldest known examples of Vertelniia, or auimala possessing a bacfe- bone of jointed segments, such as is possessed by all fishes, reptiles, birds, and mummuls.

The class of fishes which thus makes its firet appearance, e as we know, in the Upper Silurian rocks, becomes well represented in the overlying Old Red Sandstone or Devonian rocks. The Devonian fish will be found in WaU-caaes, sections SO and 39 to 41; the latter containing some fine examples of Ooccosleus, FterlchViya, and the other Old Bed Fish of Scotland ; whilat the Devonian sheUa, corals, and other invertebrate fossils are displayed partly in Wall- oases, sections 31 and 82, and partly in Flab-cases Nos. 29 to 35. Some of these fossils are of interest from the support which they lend to Professor Eamsay's view that the Old Bed Sandstone n for the most part deposited in great fresh -water lakes.

Above the Devonian or Old Red rocks come the beds forming the Carboniferoua series. Flat-oases Nos. 36 and 37 contain fossils from the Lower Carboniferous beds ; 38 to 47 contain a selection of the fine organic remains yielded by the Carboniferous or Mountain lime- stone (p. 30j i 47 is devoted to fossils from the Millstone grit; and 4& and 49 to animal remains from the coal measures. Taming to the Wall-cases, the Carboniferous series is continued in sections 33 to 35, where the beautiful corals of the Carboniferous limestone form a characteristic feature ; in sections 36 to 38, where the fine esamples of Cephalopoda attract attention ; in 42 to 45, which contain remains of Carboniferous fish ; and in 46 and 47 which are devoted to tho fish and Labyrinthodonts of the coal meaaureH. These Lahyrintho- donts— so called from the curious structure of their teeth as (Esployed in miorosoopic sections — were air-breathing croaturea belonging to the class Amphibia, which contains the frogs, toads, and newts, and which may be separated from the Reptiles hy having their respiration efl'ected in early life by meiins of giUs. Some idea of the prolific flora of the coal-measure period may be gained by studying the plant-remains in sections 48 to 64. These remains teach as that agreat variety of plants, of decidedly terrestrial habit, Nourished tbi-oagh that loug period ot time to which the formatioa

.Bbitibu Fossilb. 175

of moet of our mimorons coal beds uiiut be referred. Oryflogamtym or. flowerleas plants, in their general character like fante, moaseB, eiob-moHBefl, and horee-tails ; and cuaiferis, an order of plants which, like the fir and pine, bear eonea in which the seeds are contained, fiunished the ehief elements in the florn of the cnrbooiferouH rocks. I'rom Hooh vogetnble prodnctiona as these, growing in great Imuri- nce under the influence of an eloFoted temperatore, anil decajng 'Kith mneh rapidity in an atmoaphare charged with moiatore, oiir 'CK1 beds appear W have been formed (jee C(xtahgti£ of Jtoek Speci- tuens, 3rd ed,, p. 66).

The coal-meoBurea are ancoeeded bj the Permian rocks, forming fthe nppermoBt of the Palieoaoic aoriea. The moUoBca from thie formation are iroupod together in Flat-casee 50 and 51 ; and the fiah remains in Weill -aase, Gootiou 46.

Before dosing the notice of the Lower GaUory it ahould be men- tioned that the Table-case in fi'Ont of Wall-caaca, aectiuna 45 to 47, is devoted to specimena illustratine the atmotnre of a reptile called StoyoTtolepis ilobertsoni fromtheTriassicsandstoneof Loaaiemauth in gmshire (lee Professor Hiislay's paper in Qnarierly Journal of the Geological Society, W.ixxi. p. 433). The neighboanng Table-caaein of aections 60 to 62 contains examples of Ichthyosaurian fosails fiom the eecondary rocks. The Table-oasea on the opposite or western aide are appropriated to fossils of mnah more recent age, which will be duly noticed at p. 178.

At the head of the ataircase, on the western side, wiil bo found tbe remaina of IchHiyoeaurvji, including a fine specimen from the lower liaa of Street ; and on the stairs of the eaetem side, a re- markably perfect Fksiosaurus, from the same locality, with a niisceUaneoiis collection of the remaina of reptiles from the secondary rcKke. The iahtbyoaanrus was a gigantic reptile of aquatic habit, ftmuafaed with a long tail, and with paddlea reaombling those of the whale ; it was a creature of great size, seme specimens attaining to upwards of 24 feet in length. The plesiosanms was another extinct aquatic reptile of large aiae, and famiahed with paddles resembling those of the iohthyoaaurHB, from whioh it differed however in general form, ita roost distinctive characters being found in its compara- tively small bend and extremely long neck. Eestorationa of these Bitinct sanriana may be seen in the grounds of the Cryatal Palace at Sydenham.

Uppee Galleet.

nmeiieiiir/ at the k/t hand or eailem a SECoNBAfti ASP Tbbtiart Fossils.

Passing over the few plants and other organic remains found in the Trias or Now Red Sandstone of this country (see Wall-caae, sec- tions 8 and 6, bottom ahelf), we Imd in the first Flat-case {No. 1) foBsilB from certain rocks lying bctwocp the trias and the lias, and known as the Peiiarth or Bhrntic beds. The earliest known reptiles, Btagonolefk ond TeUrelon, occur in what is generally regarded aa Kew Eed Sandatone, and are represented in Wall-case, section 2fl, which contains also other reptilia from the secondary rocks,

Occnrring in eitraordinaiy abundance, and in an excellent state of preservation, the fossils of the Liaasic and OoWtiii fovoiWiKRiQa 11.1-

Uppbh Gallebt.

oeaaarily demand a BomQwhat large amoont of apaco. Tho group oE lioBsic rocka, farming the laweet momber, is represented in Flat-caaes 1 to 6, and in Wall-cases, sections 8 to 13. Ainmonites — bo called from the reaamhlance of this shell to the curved horn on the head of Jupiter Araioon — thronged tUo watara at this time, and gigantic CQttle-flali hftvo left their internal " bones," known as Betemnitea, BiKfliran, helanmon, a dart,) to tell of their abundance. In Wall-case, section 17, are aome fine specimena of the crinoidal ammals of tho lias ; and a collection of lias fiab from Iijme Regis ia arranged with the Oolitic vertebrata in aectiona 32-24.

The sulidiviaiona of the Lower Oulites, embracing the Inferior Oolite, Fuller's Earth, StonesHeld alate, Great Oolite, Bradford clay. Forest Marble, and Comhraah, are represented bj an exteneive series of foaails, displayed in Flat-casea 7 to 21, and Wall-oasea, aections II to 16. Ko. 18 is devoted to certain plant remains fi-om the lower Oolitea, consisting chiefly of arborescent ferna, and of planta allied to the eiciatiBg Cycas and Zamia.

The strata known as Kellaway'a rock, Oxford clay, Calcareous Grit, and Coral Eag, form together the group of MiddJa OolUet, the characte Fistic fossils of which will he found in Flat-casea 22-26, and 'Wall-casea, sections 14 to 21. The organic remains from the Eime- ridge clay — the lowest of the Upper Oolitic aerieaare placed in Flat-caeee 27 and 2B; those from the overlying Portland beda in 29 and 30; and the freah-water shells from the Purbeck rocks in. 31 and 32. Turning to the "Wall-casea, we. find in sections 22-35 specimens of Liasaic and Oolitic fish ; in 38, some interesting rep- tilian remains from the Oolites i and iu a collection of fossil inaaots, &c. from the Purbeck group.

The lower division of the Cretaceous system embraces the Weal- den beds and the Neocomian or Lower CJreensand ; the fossils from the former— for the most part fresh-water shells — areinriat-caaeSS; whUe Cases 34 to 40 contain Neocomian fossils. The Gault, a band of clay separating the Lower from the Upper Greenaand, is repre-

the beautiful fossils from

The Blackdown beda

44 and 4o,,whibt

43, and the Folkestone Gaultare eapeciaUy oonapi

of Devonshire have yielded the fine fo as:

tho Upper Greensand has contributed the large series exhibited ii. Nos. 46 to 49; the Coprolite deposits worked arouad Cambridge having furnished many of the latter fossils. Tho Chloritic Marl ia repreaented in No. 50, the Lower Chalk in 51, and the Upper Chalk in 52 and 53. Turning to the Wall-caaes, we find in aecttons S8 to 30 a collection of sfiongea, crustaceans, cephalopoda, &c., from the Tfeocomian beda and the Gault ; in sections 31 to S3 the Ifeo- comian and Gault foaaila are continued on the lower shelves, whilst the bulk of the case is devoted to apeoiniens from the Upper Green- sand of Cambridge and Wiltahire, from the Blackdown beda, from the Chloritic Marl, and from the Bed Chalk : the laat is a deposit which occurs locally at the base of the White Chalk, and ia eipoaed at Hunstanton on the coast of Norfolk, and at Speeton Bay in York- shire. Then in sections 34to37 the serieafrom tne Upper Greensand ia conclnded, and the fossils of the Chalk form the bulk of the col- lectioa. The Cretaceous Vertebrata, mostly fish, are exhibited in sections 38 and SB, but for want of sufficient space here, part of the collection is placed in the drawora of the Table-cases in the Lotoer Gallery.

Having now reached the close of the secondary epoch, we advance to the tertiary division, including the Eocene, Meiocene, and Plcioceno groups.

Comraenoiiig with Flat-case No. 54 we find u selection of foaaila the Thtuiet Sftnila, which orerlie the chalk ; thou ia 55 we have fossils from the Woolwich and Eoading bods, or the " Plaatic clay " or the older geolDgistsj and from the Loudon claj — the thick depoaiC of stiff claj on which the motro](olis is seated. Iii No, 56 the Lomion- day Beries ia continued, and in Caaes 56 to 59 the Brackloaham bada are represented by a series of beautiful marine shells. Cosea 59 to 61 contain a aet of equally Sno fossils from the Barton series ; and the remaining cases are derotod to the other Upper Eocene fossils, in- clnding the Headon aeries in Cases 61 and 62: the Osborne and 3t, Helen's bede in 62 ; and the. Bcmhride and Hempstead aeries in 6ii, In connexion with this Eocene collection it should be mentioned that the gftsteropods will be fomid in the drawers beneath the Mat-oasea.

Eocene fossils of a diif'erent character, including plants, echin- oderms, cephalopoda, and yertebrala, are exposed iii the adjoceat Wall-cases. In section 47 we find fossila from the Thanot beds, the Woolwich and Reading aeries, and the London clay. Section 48 containsfoBsils of the Lower BagshotiBruckleaham, fiartoo, Headon, Berobridge and Hempstead beds. Section 49 is devoted to Eocene fish, whilst 50 contains reptiles, with a few ramaiua of birds ; and Bl, the Eocono mammalia.

The Meiocene planta, chiefly from the lignite-beds of Bovey Traoey. in Devonshire, are grouped together m. Wall-caso, section 69. The foasila of the Pleiooene deposits, known as the Crags of BofTolk and Norfolk, are exhibited in sections 53 to 56 ; whilst the remaining cases are devoted to a collection of poat-pleioceno fossils.

The Craga are generally divided into the white or Coralline Crag, the Bed Crag, and the Norwich or Mammaliferoua Crag. Each of these sections is well re])rGsented, many of the finest fossils having been obtained from the workings for the ao-called copi'olites, exteu- Bively carried on in the Red Crag.

To continue our survey of the palseontological collection, it is neceaaary to rotarn to the Lower Gallery, where ll sectionB of the Wall-cases, and two Table-casea on the west-side are devoted to Pleiocene and Post- pleio cone ibaails, mostly vertebrata, InWall-coso, aections 1 and 2, we find a collection of vertebrate remains of Pleio- cene age from the Croga of Eoet Anglia. Prominent among these are the large car-bones of extinct wbalea, and the teeth of Mastodon, a creature related to the elephants, but having teeth farnished on the grinding surfaces with j-ipple-like projections. The aucceeding sectmns of the Wall-cases 3 to 11 are devoted to the remains of Poat-

pleiocene mammalia. Here will be found some fine apecimena from the brick-earth of Ilford and Crawford, including numevoua esamples of extinct species, anch as the teeth of the woolly-haired rhinoceros (BhmoceroE tichorhiime), of the mammoth {Ekphaeprimigmias), and of other species of elephant no longer living. The hiataectionof this series of cases, No. 11, contains some Lnteresting speoimens of mam- malian remains from Kent's cave near Torquay, in Devonshire, and from the Wookcy Hole hyena-den in Somersetire. In these cavea we find many of the extinct Post-pleiocene mammalia, as those here represented, associated with the earliest known remains of oor own apeciea. These ancient relics of man occur in the shape of rudely-worked unpolished flint implements, such as have already been described at p. 61. Before leaving this collection, attention shonld be directed to the fine skill of the muak ox, or rather sheep, {Om'Job moscliaiue] , which waa found by Profeasor BoydDawkins in the briok-corth of Crawford in Esses, and now stands in eection. 1 . T\ia MBfll sheep ia at present a native o£ Arctic ijaci:\ca.,\i\:\Ti wsosmsro.

" 17S OTPBR' GALtBRT. 1

with other northern mammalia must have inhabited this country daring part of the Pleistocene period,

Oar survey of this dopftrtraont wonld be incompletfl without refer- ence to the two adjacent Table-oases, which contain a remarkably finecollectionof fbsBilB from the Forest bed of Cromer on the coast of Norfolk. For more than 40 miles along thia coast the remains of a buried Forest are to be foondi and aBHOciated with the atumpa of trees aro numerous antlers of deer, teeth of the elephant and rhinoceros, and other relics of the terrestrial fauna of the period. The present ooUecttoQ, which was got together and presented oy the KoT. 8. W. King, contains some fine apeoimens of Gervtis SedgmiakU, Trogonotkriimi CiwierU, Rhinoceros etmecue, Blsphaa meridiowilig, aaid other mammals, some of which are etill living, whilst Others aro extinct.

Sach 13 a rapid ontline-sketch of this valuable collection of fossil remains, the study of which will be greatly facilitated by observing on the Geological Maps and Sections the order whieb the respective formatioufl observe to each other. Especially in the Memoirs of ifte Ofologi':ttl Survey and MnaeM/m of PraetUal Geoloffij will information be found on these and other important allied sabjects.

Gbologioal Eock Speoimmn'S.

The Peirologicai, CotLEcrioif, or Collection of Geological Bock Sfecueess will be found in the recesses of the second gallery. A eatalogne of these is published under the direction of Professor A. C. Eamsay, but although three editions have been issued they are at present exhausted. It is only necessary, in this place, to give a general notice of the principal groups.

The sorioa of Igneous Eocks are arranged chic on the western aide, commencing at the Fouth-west comer with Wall-case No, 1, in which will he found sonie interesting examples of lavas and other Tolcanic products, fVora the promontOTy of Aden, at the month of the Red Sea, and from Kilauea and Hawaii, in the Sandwich Islands. These are followed by a series of dioi-ites, trachytes, and other igneous rocks from certain mining districts in Hungary, Croatia, and Transylvania. In this case are also grouped a few specimens from the Eifel, St. Vincent, and Teneriffe.

Wall-case 2 contains a tolerably extensive set of igneous rocks from Ascension Island, and the Galapagos Archipelago, presented by Mr. Darwin.

Ifew Zeo2an3 also furnishes some interesting volcanic products, which are here exhibited.

The following case, No. 3, is occumed by a collection of specimena from the extinct volcanoes of the Ehino, and from the Island of Madoria. On the upper shelves of Cases 2 and 3 are some very chajactoristic models of limestone, gneiss, and other rocks, together ivith a model of the island of Bonrbon,

Before passing to the next compartment it is desirable to notice the objects in tbe recesses on this aide of the rallery. In the first recess, opposite Case 2, is an instructive niodel of Arthvj'g Seat, Edinbiiijh, showing the geological structure of that volcanic hill; and in the next recess, opposite No. 4, is a Table-case (A), containing a model of Vesuvius, and an extensive series of Vesnvian rooks and minerals. With those are associated some specimens from Hecia, and some samples of melted Eowley Eag (p. 47). In the same case ir/// be found an instructive model of Graham's Island, an island

British Bock& 179

wliioh was thrown np in the Mediterranean, near Sicily, in the Bummer of 1831, and, after continuing some time in a state of ' violent eraption, gradually diminished in size, and finally dis- appeared about three months after its first appearance.

In the Table-oaae B, occupying the next recess, is a geological model of Etna, together with a valuable collection of volcanic prodncte from jStna, and from the extinct volcanoes of the Papal States.

Leaving the series of modern volcanic products, we, turn to those rocks in which the igneous origin is less obvious, although still indnbitoble; such, for example, as the basalts. These are re- presented in the remaining Wall-cases in the recesses on this side of the gallery ; and with these truly igneous products are associated certain rocks of questionable origin, such as granite, serpentine, <&c. As most of these nave been already described in connexion with the objects in the hall, it will be necessary merely to give the refe- remces where such notices may be found. The series commences in Wall-case No. 4 with a collection of the different varieties of granite (p. 24), from which we pass through the group of syenites to the greemtonea (p. 27), with which are exhibited samples of the ash, and other mechanical accompaniments of the trappean rocks.

The upper and lower shelves of Case 5 are appropriated to ex- amples of the columnar basalt and associated rocks in the neigh- bourhood of the Griant's Causeway (p. 47) ; and in the same case are grouped some fine specimens of Cornish serpentine (p. 29). The remainder of this case, and the whole of the following one, contain specimens forming part of the collection of British stratified rocks, to be presently noticed.

Table-case 0, at the head of the staircase on this side, is devoted io specimens Ulustraiive of Glacial 'phenomena.

Tne common form of a glacier is that of a river of ice, filling a valley, and pouring down its mass into other valleys yet lower. It is not a frozen ocean, but a frozen torrent. The (xlacier moves on like a river, with a steady fiow, although no eye sees its motion ; but from day to day, and from year to year, the secret silent cause produces a certain slow effect. The movement of such a mass of ice as that which constitutes a glacier must be exhibited in enor- mous manifestations of force. Hence, we find the glaciers of the Alps grinding the rocks, on either side of the gorges through which they glide, with irresistible power. The specimens exhibited show the wearing and grinding force of the modem glaciers ; and the discovery of similar scratches on the rocks of Snowdon and other places proves the presence, at one time, of glaciers in the mountain valleys of this country. See Professor Eamsay's Eemarks on Glaciers, in the CatoLogue of Rock Specimens, and in The Old Oladers of North Wales.

Crossing to the opposite or eastern gallery, we commence notice of the collection of Bkitish Sedimentaky Eocks. These are ar- ranged stratigraphically, in ascending order (see Table of Strata, p. 172), commencing in Wall-case 40, with the lowest of the PalaBO- zoic series, or oldest stratified rocks, represented by a small group of specimens from the Lav/reitian gneiss of the north-west of Scotland, and the adjacent islands. These are succeeded by the Cambrian grits, slate, &c., with their associated igneous rocks, chiefly from North Wales, the Longmynd, and Charnwood Forest. Above the Cambrian comes the Silurian system, the lower division of which comprises the Lingula and Llandeilo flags, the Caradoc or Ba beds and the Lower Llandovery rocks, leglecting minor

180 vpp. okiLKar.

BubdivisionH, the TJjiper Silurian Beries conaiats of tlie Upper JAaa- dovffrij rocks and the Wenloeh awd IauUoiv gi-oupa, including many beds of highly fossiliFerous limestone. The Silurian rocks, which are chiefly from Wales, where they aro Tery largely developed, are dietribnted through GaaeB 41, 43, and 43.

Between the Bilnrian and Carboniferoos syatema occtir the slaty rooks of Cornwall and Devon, forming the Vevoman group, and the strata long known as OW Bed Sandetone, largely developed on the borders of Wales and in Tarions parts of Scotland. The Carboniferous system., to which we nw pass, is divided, in this country, into the C(on{fercms liTiiesUme, imllalrme grit, and ioal measwret. The Carboniferous or Mountain Jimeatone is especially prominent in the north of England, where it forms the Pennine chain {p. 30) ; in Derbyshire it is associated with the "toadetone" (p. 30), of which several examples are here shown. The millatono grit haabeeunoticedat p. 36. The " coal measures" is a eoLective term applied to the alternations of shale, sandstone, fireclay, coal, nnd ironstone, which occur aesociated in moat of our coal fields. In Cribs 48 and 44 will be found representatives of the coal measures of South "Wales, Dean Forest, Coalbrook Dale, Flintshire, South Staffordshire, Warwicksbiro, Lancashire, Derbyshire, York- Bhii-e, and Northumberland.

The Fermian rocks, overlying the coal messttrea, and forming the uppermost member of the Palfflozoio aeriea, are represented by the conglomerates, dolomites, (p. 39,) &c. in Oaae 44.

Before concluding the examination of the Palieozoic rooks, attention should be given to the Table-cases in the reeeaaes on this aide of the gallery. These cases, marked reepecttvely D, E, F, are appropriated to a collection of Scotch rocks fivm.tha Old Sed SajtiZ- BtoTie and Carboniferous eyslema, including a large series of the associated igneona rocks.

Turning to ('ase 45 vf e find the lower rooks of the secondary or Mesozoio epoch, commencing with the Xew Sed Sandetone or Trias. Above the Trias are the foasiliferous rocks known variously aa the Penarth, RhBetic, and Wcstbury beds. These deposits form a transition to the overlying Lias{p.S7), agroap of clays, argiiiaceous limestones, and marls, regarded usually as the base of the Oolitic system, and divided into an upper and a lowei" group, separated by the marlstone. The limestone of the Oolites have been noticed at p. 37 ; and the numerous subdivisions of iiie system at p, 176 ; each of these ficda ita repreaentatives in Case 46.

The remainder of the collection of British stratifled rocks will be found on the opposite side of the gallery in Oases 5 and 6, to which we now re-croas. The Oolitic series ia continued in Case 5 (north aide) ; the fresh-water deposits ipiown aa the Fwrbeck beds being there represented. Then follows the Lower Cretaceous group, comprising the Wealdgn beds "and the overlying Lqiikt Oi'eenseuid, or Neccomian.

The GauU, Upper Greensand, and Chalk, forming together the rjipei' Cretaceous series, receive illustration in the following Case, 'So. 6 ; where also will bo found the Tertiary or Cainozoio rocka, Those are divided into the Eocmie, Mcioeene, and Pleiaceae groups {p. 172) of which the lowest, or Eocene, occupies two depressed areas in the chalk, known as the tiondon and Hampshire baains, the latter extending to the Isle of Wight. These are followed by tie Meioceae faods, which are but feebly represented o-:'"'-

ocurring only at Bovey Tracey, ftr -neiocene rooks are represented by

tte Crags o? o'

HpDEL OF ABBAN. 181

In this case are also grouped together specimens from the drift- gravels, boulder-clay, <&c. ; and, finally, in Case 6, we have a collection of specimens from raised beaches, caves, and other recent formations.

In firont of the entrance to the Mining Eecord Office stands a model, by Professor A. Greikie, F.B.S., illustrating the geological structure of the Isle of Eigg, in the Hebrides.

Before leaying this part of the gallery, it should be mentioned that at the time this Edition of the Guide is being revised, (Autumn of 1876,) alterations are contemplated, by which the collection of rock-specimens will be removed to cases where it can be exhibited to much greater advantage. As the suggested improvements will necessitate an entire re-arrangement of the objects in this part of the Museum, it seems unnecessary to enter into further details as to their present position. The following objects, however, require special notice.

Model op the Isle of Arran. By Frofesaor -4. C. Bamsay, LL,D,, F,B.8.

This model is on a horizontal scale of two inches to a mile. The vertical heights are somewhat exaggerated. The best idea of the form of the more mountainous part maybe obtained by bringing the eye to the level of the model at the S.E. comer. These mountains ponsist of granite, forming a circular mass at the north end of the island, about eight miles wide in all directions. The highest point (Groatfell) is 2,969 feet above the level of the sea, and rising directly from the shore, it looks even higher. This mass is surrounded by clay slate, chlorite slate, gneissic and other metamorphic rocks, the metamorphic action having been induced by the granite which they surround. In their turn they are overlaid by the Old Bed Sandstone, on the east at Glen Sannox, and on the south between Brodick and the west coast north of Mauchrie Water. It is in great part con- glomeratic, and pebbles of the underlying metamorphic rocks are contained in it, showing that they were altered before the deposition of the Old Bed Sandstone.

The coal measures (lower coal measures) rest on the Old Bed Sand- stone at Brodick bay, and south of Glen Sannox, but between these points they rest, first on the slaty rocks, and then on the granite, showing that they lie on the old strata unconformably. They are also found about three miles off the N.E. coast of the island, lying on metamorphic slaty rocks. The limestones, which are interstrati- fied with the sandstones and shales, contain the usual carboniferous fossils. Coal-measure plants are found in the sandstone and shales, and thin beds of coal occur near the salt pans. On the S.W., coal measures also appear in the valleys where the trap rocks have been removed by denudation. The New Bed Sandstone overlies the coal measures at the Cock of Arran (N.E.), and also forms the major part of the coast of the S.E. of the island. It is doubtful, however, whether these rocks do not in reality form only a higher part of the coal measures. The major portion of the south part of the island consists of felspathic traps and greenstones of comparatively late geological date, for they have broken through the stratified rocks indiscriminately and overflowed them, so that in general it is only in the valleys that the underlying strata of coal measures, &c., hate been exposed by denudation.

' Sulphate of baryta is obtained in tolerably large quantities on the hill to the south of Glen Sannox, and in the bed ot -msXV onginating in. Corrie na Chiodh.

JFPKB OALMaW'

Model or a Portios o

This model represents the coast of the Isle of Wight hetween S&ndown Bay and Whiteclift" Buy. The almost vertical poeition of theohiilk is well iodicated by the layere of dark flints occurring in the opper chalk. The tertiary heds which rest on this highly in- olined chalk are, in ascending order, the plastio clay or Woolwich and Reading series, the London clay, the varioua aubdivisiona of the Bagshot beda, the Hendou aud OHbome Berifis, and the Bern- bridge heda. (Sea Mr. Eriato-w'a Memoir on " The Geology of tha Isle of Wight.")

PnOPOBTiONAi, Sechos oj the Himalaya mawntnins, upon the panel near Wall-case 7.

The height from tbe floor of the principal room of tte Moaeua. to the line on the brass plate which represents the level of the sea, which is STi feet, being oonsidered equal to the dianieter of the earth, this section shows the height of the Himalaya monntaias, as compared with that diameter. The height oF the inost elevated portion of this range approactes to 30,000 feet. Tbe Eartfli's diameter being about 8,000 miles, it follows that the greatest elevation above the sea level is less than the 1,600th part of that diameter.

Against the door on eastern side will be found a seak of reitiipa heigliU as it gedlogital Btandard scale, BUggcsted by Mr. P. JJasmyth.

A, B, repi'esenta an arc of a circle 66 feet in dianieter, represent- ing 120 miles of the Earth's Hurfaoe, at the sea level, to the scale of 1-lOth of an inch to a mile, on which are represented the relative heights of

Ist. Snowdon - . - . 3,571 fejt.

2tid. Vesuvins ... - 3,800 .

Srd. Etna 10,874. 4tli. Mont Blano - - - - 1-5,733

5th. Mount Everest, Himalaya - - 29,000 ,

6th. The deepest mines - - 2,200 ,.

7th. The probable average of the whole Earth above tie level of the sea. Several geological pltotograplis, presented by Mr. J. J. Cole, F.B.A.S., ore suspended against the panels at the suutheru end of the gUei-y.

In the south-east corner stands a model of the eait miwe of Aussee, forming a companion to the two similar models on the principal floor, described at p. 60.

Bun ab Planets.— Above the door of the Mining Eeoord Office in this gallery is placed a gilded globe, which is intended to repre- sent the Sun. At relative distances, in comparison with the siae of this sphere, there are placed, upon projecting anna boia the table- cases, representations of Mereivnj, Venue, aiid ot Eo/rtk, with her satellite the Moon. This arrangement is intended to familiarize the mind with the immensity of space, and the size of the msaea of those planets which are nearest the groat centre of the system, in which the earth is a small unit. The great size of the Snn will be conceived by looking at the eurth — a globe nearly 25,000 miles in circumforouce, and her satellite of a correct comparative size, at tlie propel- relative distance from her. If the centre of the Sno and -Eanh wore aojacident, the Mooh circulatiBg iu her orbit at the same tf/stanco from the aith as sho now moves, viO\iAtBvo\\si'y(\fliaii.\:W

Mining Record Office. 183

mass of the Sun, and leave a space beyond equal to tlie distance of the Moon fom us, before reaching the edge of the solar disc.

Cervtis megaceros or Megaceros Hibernicus {the Irish Elk). — The skuU and antlers of this remarkable animal, of which numerous remains have been found in the peat bogs of Ireland, are placed above the cases at the circular end of the upper gallery. It is an extinct species of post-pleiocene age, remarkable for its size, the spreading antlers measuring in some specimens as much as 10 feet from tip to tip. It is clear that the antlers usually embedded in peat-bogs have not been shed, for they are found attached to portions of the skull, proving that the whole animal perished. The so-called Irish Elk probably belonged to the group of true stags, and not to the Elks as was at one time supposed.

Miniito Eecord Office.

This branch of the establishment owes its origin to a representation made to the Government by the British Association at the meeting of that body at Newcastle-on-Tyne in 1838.

The objects to which this office is devoted are : —

1st. The collection, arrangementy and Reservation of all 'plans and sections of mines amd collieries, both those which are now in process of work, and such as have been or may be abandoned.

2nd. The collection and pvhlication of statistical information con- nected with the mineral produce of the United Kingdom.

3rd. The collection and registration of every hind of information connected with the phenomena of our mineral formations of whatever description these may he.

The President of the Geological Society, the Rev. Dr. Buckland, in 1841, who took an active part in the establishment of the Mining Recobd Office, thus spoke of its objects : — " To the Keeper of these Records will be assigned the duty of arranging the documents which may be transmitted to him from all parts of the kingdom by any engineers, mineral surveyors, and proprietors of mines and coal works who may be willing to send them ; particularly itfaps. Sections, and Underground Flans, which will record the state of each mine when it is abandoned, for the information of those who, at a future period, may be disposed to bring it again into operation."

At the present time the Mining Recokd Office contains a large collection of the Plans and Sections of abandoned and of existing mines, and a considerable amount of information connected with the mineral produce of the United Kingdom. To all parties who are specially interested in these industries, the collections of the office are opened upon application to the Keeper of Mining Records. Statistical returns of the mineral produce of these islands are pub- lished annually ; these returns being indeed the only reliable infor- mation which is given to the public of a branch of British industry, the value of which, independently of building stones, amounted in 1874 to 67,839,6972.

A Catalogue of the Documents in the Mining Record Office has been published.

'I'

London:

Printed by Georoe E.. Eyre and Wuliam Spottiswoode, Printers to the Queen's most' Excellent Majesty.

For !Her Majesty's Stationery Office. [10445.— 5000.— 11/76.]