A practical treatise on hydraulic mining in California : With description of the use and construction of ditches, flumes, wrought iron pipes, and dams

Bowie, Augustus Jesse · 1885 · Historical

A practical treatise on hydraulic mining in California : With description of the use and construction of ditches, flumes, wrought iron pipes, and dams by…

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GMtrtlLibraiy System Mldlion,WI 53706-1494

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Scale, 18 Miles To One

A

Practical Treatise

Hydraulic Mining

California.

Description Of The Use And Construction Of

Ditches. Flumes, Wrought-iron Pipes, and Dams;

FLOW OF WATER ON HEAVY GRADES, AND ITS APPLICABILITY, UNDER HIGH PRESSURE, TO MINING.

AUG. J. BOWIE, Jr.,

Mining Engineer,

New York:

D. VAN NOSTRAND, PUBLISHER, 23 MuRRAV AND 27 Warren Street.

Copyright, X885,

by

D. Van Nostrand.

This Work Is Dedicated

To

RossiTBR V/. Raymond, Fh.D.,

Bv

THB AUTHOiU

Contents.

Chapter I.

The Records Of Gold-Washing.

Page

Siberia, Asia Minor, Italy, Spain, France, Africa, India, Asiatic Isl- ands, China, Japan, Russia (Table i. Yield of gold in Russia), Brazil, Chili, Bolivia, Peru, Venezuela, U. S. of Colombia, Mexico ; Australasia : Victoria, New South Wales, Queensland, South Australia, New Zealand ; Canada, British Columbia ; U. S. of America : New England, Virginia, North Carolina, South Carolina, Georgia, Idaho, Montana, New Mexico, other States and Territories, 15

Chapter Ii.

History And Development Of Placer-Mining In California.

First Mention of California. Discovery of Lower California. Early Explorations First Mention of Gold. First Mission in Lower California. First Mission in Upper California. Eajrly Dis- coveries of Placers. Marshall discovers Gold at Coloma. Other Gold Discoveries. First Publication of Gold Discoveries. First Attempt to build Ditches. First Use of the Long Tom." Discovery of Gold-Quartz Veins, First Working of Deep De- posits. Sluicing. First Use of the Hydraulic Method. Canvas Hose. Iron Pipe. Inverted Siphons. Improved Nozzles. First Rifle. Deflector. First Drift-Mining. Table MounUin. Deep Tunnels, 43

Chapter Iii.

General Topography And Geology Of California.

The three Great Belts of California.— i?// the Coast Ranges : Topographical Limits. Mountain System. General Topographi cal Structure. General Geological Structure. Metamorphism. Cretaceous Formations. Coal and Cinnabar Deposits. Tertiary Strata. Asphaltum Deposits. Tin Ore. Pliocene Gravels. Gold, Silver, and Copper Veins. Eruptive Rocks. — Great Valley of California : General Topography. Drainage. Rain- fall. — Belt of the Sierra Nevada: Topographical Structure. General Geological Structure. Granite. Auriferous Slate For- mation. Gold-Quartz Veins. Carboniferous Limestones. Ma- rine Sedimentary Deposits. Lava. Sedimentary Volcanic Layers. Gravel Deposits. Deposits at La Grange, 53

8 Contents.

Chapter Iv.

The Distribution Of Gold In Deposits And The Value Of Diffeebnt

Strata.

Pags

Top Gravel sometimes pays. Gold in the Grass-Roots. Pay Gravel sometimes high above Bed-Rock. Pay Gravel generally near Bed-Rock. Tuolumne River Claims. Nevada County. Sand generally poorer than Gravel. Rich Pay in Undulations and De- pressions. — Examples of the Comparative Values of the Different Gravel Strata : North Bloomfield. PatricksviUe Light Claim. La Grange Light Claim. Polar Star Mine, 70

Chapter V.

Amount Op Workable Gravel Remaining In Caufornia.

Minimum Pay Yield, 76

Chapter Vl

The Different Methods Of Mining Gold-Placers.

Miners' Classification of Deposits. Classification of Mining Openu tions. — Surface-Mining: Dry- Washing. Beach-Mining. Bar and River Mining. Ground-Sluicing. Booming. — Deep-Min- ing : Drifting. Fig. i. Sunny South Mine. Hydraulic Mining. Origin in California. Hydraulic vs. Drift Mining. Require- ments for Financial Success, 78

Chapter Vil

Preliminary Investigations.

Indications. Explorations at Malakoff. Fig. 2. Section of Malakoff

Shaft No. I, 87

CHAPTER Vin.

Reservoirs And Dams.

Storage Reservoirs : Sources of Water-Supply. Requirements for Sites. Elevation. Streams. Rainfall. Snowfall. Absorption and Evaporation. Reservoir Gauge. Reservoir Statistics. Distributing Reservoirs. Table 2. Reservoirs on the Yuba, Bear, Feather, and American Rivers. — Dams : Foundation. Wooden Dams. Abutments. Masonry Dams. Fig. 3. Section of Dam. Earthen Dams. Puddle Walls. Shrinkage of Em- bankments. Table 3. Angles of Repose and Friction of Em- bankment Materials. Fig. 4. Dry-Stone Dam. Dams in Cali- fornia. Table 4. Principal Dams in California. — Bowman Re servoir and Dam : Main Dam. Fig. 5. Bowman Main Dam. Waste Dam. Fig. 6. Bowman Waste Dam. Debris Dams. Table 5. Rainfall at North Bloomfield and at the Bowman Dam. Table 6. Rain and Snow Fall at Bowman Reservoir, ... 90

Contents. 9

Chapter Ix.

Measurement Of Flowing Water.

Pacb

Weirs. Orifices. Open Channels. Formula for Discharge over Weirs. Discharge through Triangular Notches. Fig. 7. Con- struction of Triangular Weirs. Table 7. Discharge of Water through a Right-angled Triangular Notch. Table 8. Coefficients of Discharge through Rectangular Orifices — Miner's Inch : Smartsvilie Inch. Other Inches. Determination of the Inch ; Experiments at Columbia Hill. Fig. 8. Experiments on the Inch at Columbia Hill. Flow of Water in Open Channels. Kutter's Coefficients for Roughness. Ditches in California. Ex- amples of Value of Coefficient in Ditches, . . 119

Chapter X.

Ditches And Flumes.

Ditches : Location and Construction Principles. Surve3dng a Ditch Line. Narrow and Deep vs. Broad and Shallow Ditches. Excavating the Ditch. Examples of Ditches. North Bloomfield. Fig. 9. North Bloomfield Main Ditch. Milton Company. Fig. 10. Milton Ditch. Eureka Lake. South Yuba Canal Com- pany. Smartsvilie Ditches. SpringValley and Cherokee. Hen- dricks. La Grange Ditch. Fig. 11. La Grange Ditch. Fig. 12. La Grange Wall Ditch. Fig. 13. La Grange Flume. — Flumes : Flumes vs. Ditches. Grades. Fig. 14. Flume Construction. Planking. Sills and Posts. Curves. Waste-Gates. Precautions against Cold. Experience in the Black Hills. Fig. 15. Wyom- ing and Dakota Co.'s Flume and Ditch. Details of Construc- tion. Lumber: Table 9. Table 10. Table 11. Bracket Flume. Figs. 16 and 17. Miocene Co.'s Bracket Flume. Details and Costs of Milton Ditch and Flumes. Table 12. Cost of Milton Ditch. Fig. 18. Milton Flume. Table 13. Dimensions and Costs of Ditches (including Flumes), . . . . . 135

Chapter Xl

Pipes And Nozzles.

Wrought'Iron Pipes : Inverted Siphons. Thickness of Iron. Table 14. Thickness and Weight of Iron for Pipe. Fig. 19. Texas Creek Pipe. Table 15. Tensile Strain on Wrought-Iron Pipe. Table 16. Area and Weight of Wrought-Iron Pipe. Riveting. Table 17. Sizes of Rivets. Table 18. Details of Riveting a 22- inch Pipe. Joints. Fig. 20. Lead Joint. Fig. 21. Method of Tightening Leaky Joints. Fig. 22. Elbow for Short Curves. Fig. 23. Method of Strapping Elbows and Pipes. Fig. 24. Air-

10 Contents.

Valve for Pipe. Fig. 25. Blow-off for Pipes. Fig. 26. - Acting Air- Valve. Preservation against Rust and Accidents. Filling Pipes. — Statistics of Pipe-Lines : La Grange Hydraulic Mining Company. Table 19. Cost of Iron Pipe at North Bloomfield. Spring Valley Water Co. Table 20. Details of Construction of Spring Valley Water Co 's Pipe. Virginia City Water- Works. Fig. 27. Profile of Pipe-Line of Virginia City Water Co. Spring Valley and Cherokee Hydraulic Mining Com- pany. Fig. 28. Profile of Pipe-Line of Spring Valley and Che- rokee Co.'s Pipe. Table 21. Details of Spring Valley and Chero- kee Pipe. Flow of Water through Pipes. Table 22. Flow of Water through Circular Pipes. Pressure Box : La Grange Pressure Box. Figs. 29, 30, 31. North Bloomfield Pressure Box. — Supply or Feed Pipes : Fig. 32. Distributing Gate. — Discharge Pipe or Nozzle : Fig. 33. Goose Neck. Fig. 34. Globe Monitor. Fig. 35. Hydraulic Chief. Dictator. Fig. 36. Little Giant. Fig. 37. Little Giant Rifle. Fig. 38. Hydraulic Giant. Fig. 39. Monitor Hydraulic Machine. Deflector. . . . . . 158

Chapter Xil

Various Mechanical Appliances.

Derricks, Hurdy-Gurdy Wheels: Experiments at North Bloomfield. Table 23. Experiments with Hurdy-Gurdy Wheels at North Bloomfield. Figs. 40 and 41. Hurdy-Gurdy Wheel and Derrick Hoist. Figs. 42-43. Hurdy-Gurdy Wheel and Nozzles. Ex- periments at Empire Mill. Tests at the Idaho Mine. Fig. 44. Pelton Wheel. Tests at the University of California. Flat Buckets. Curved Buckets. Figs. 45, 46, 47, 48, 49, 50, 51, 52. Buckets for Hurdy-Gurdy Wheels. Fig. 53. Pelton Wheel. Figs. 54 and 55. Diagrams of Efliciency of Pelton Wheel. Fig. 56. Diagram of the Comparative Efficiency of Wheels. The Pan. The Batea. Fig. 57. The Rocker. Fig. 58. The Tom. Puddling Box. Amalgam Kettles 185

Chapter Xiii.

Blasting Gravel Banks.

Blast at Smartsville. Fig. 59. Diagram of Powder Chambers. Blue Point Blast. Paragon Mine Blast. Fig. 60. Blast at Paragon Mine. Dardanelles Mine Blast. Blasting Powder. Methods of Blasting. Table 24. Bank Blasting at the Manzanita Mine. Firing by Electricity. Fig. 61. Arrangement of wire for firing by Electricity. Tamping, , 206

Contents. 1 1

Chapter Xiv.

Tunnels And Sluices.

Page

7lM//f.' Shafts for Tunnels. Shaft Timbering. Second Shaft. First Washing. Size of Tunnel. Location of Tunnels. — Sluices: Grade. General Grade adopted. Size of Sluice. Details of Construction. North Bloomfield Tunnel Sluice. Figs. 62, 63, 64. Tunnel Sluice Box at North Bloomfield. Bed-Rock Claim Sluice Boxes. La Grange Sluice Boxes. — Rifflts : Block Riffles. Advantage of Block Riffles. Life of Blocks. Rock Riffles. Blocks and Rocks. Longitudinal Riffles. Bed-Rock Riffles. — Branch Sluices : Fig. 65. Turn-in Sluice, Patricksville. Turn out Sluice. Fig. 66. Box of Turn-out Sluice. — Undercunents : Figs. 67, 68, 69. Undercurrent at North Bloomfield. Table 25. Lengths and Grades of Tunnels at Smartsville, Yuba County, Cal. Table 26. Lengths, Grades, and Costs of Tunnels in Ne- vada County. Table 27. Cost of Construction of the French Corral Tunnel and Sluices. Table 28. Cost of Construction of the Manzanita Mine Tunnel and Sluices, 315

Chapter Xv.

Tailings And Dump.

Tailings : Composition of Tailings. Wear in Running Water. Ef- fects of Hydraulic D6bris. Table 29, Hall's, and Table 30, MendeU's, Estimate of the Amount of Debris in certain Rivers in California. — Dump : Working on different Bed-Rock Levels with same Dump. Tailing into Streams. Experience at La Grange. Exceptional Cases, 236

Chapter Xvi.

Washing, Or Hydraulicking.

Chaining the Sluices. Commencing Work. Caving Banks. High Banks. Light. Electric Light. Continuous Work. Cleaning up. Treating the Quicksilver and Amalgam. Retorting. Figs. 70 and 71. The Retort, 244

Chapter Xvii.

The Distribution Of Gold In Sluices.

Distribution in Tail Sluices. Fig. 72. Tail Sluices and Undercurrents. Table 31. French Corral Undercurrents ; Yield of the Under- currents, etc., at the French Corral Mine. Table 32. Manzanita Mine Sluices. Table 33. Distribution of Gold in the Manzanita Mine Sluices. Table 34. Distribution of Gold in the French Corral Sluices. Table 35. Distribution of- Gold in the North Bloomfield Sluices, 252

12 Contents.

Chapter Xviii.

Loss Of Gold And Quicksilver.

Page

Loss of Quicksilver. La Grange. North Bloomfield. Table 36. Loss of Quicksilver and Yield of Bullion at North Bloomfield. Delaney and New Kelly Claims. Table 37. Run at the De- laney and New Kelly claims. Loss of Gold, 263

Chapter Xix.

The Duty Of The Miner'S Inch.

Table 38. Estimates of the Duty of the Inch, Mendell. Table 39. Estimates of the Duty of the Inch, Payson. Table 40. Esti- mates of the Duty of the Inch, State Engineer. Table 41 A and B. The Duty of the Inch at North Bloomfield and La Grange, . 368

Chapter Xx.

Statistics Of The Costs Of Working And The Yield Of Gravel.

Table 42. Details of Working the French Hill Claim. Table 43. Details of Working the Light Claim, Patricksville. Table 44. Details of Working the Chesnau Claim. Table 45. Details of Working the Johnson Claim. Table 46. Details of Working the Sicard Claim. Table 47. Resume of Workings by the La Grange Co. Table 48. Details of Working No. 8 Claim, North Bloom- field. Table 49. Classification of Mines and Mining Expenses. Table 50. Yield of Important Hydraulic Claims in California. Table 51. Yield of Various Gravel Claims in California. Table 52. Yield of Gravel in Foreign Gold Fields, 275

Appendix A, aSi

Index* 293

List Of Illustrations.

Pagb

Fig. I. Sunny South Mine, Placer Co., Cai 85

Fig. 2. Shaft No. I, Malako£f, 89

Fig. 3. Rankine's Section of Dam, 98

Fig. 4. Dry-Stone Dam loi

Fig. 5. Bowman Main Dam, A and B (3), 106-7

Fig. 6. Bowman Waste Dam, A and B (2), ill

Fig. 7. Construction of Triangular Weirs, 121

Fig. 8. The Inch Gauge, 125

Fig. 9. North Bloomfield Main Ditch, 139

Fig. 10. Milton Ditch 139

Fig. II. La Grange Ditch, 141

Fig. 12. La Grange Wall Ditch 141

Fig. 13. La Grange Flume, 142

Fig. 14. Flume Construction, 143

Fig. 15. Profile of Wyoming and Dakota Company Flume, . facing 147

Fig. 16. Bracket Flume of Miocene Company, . . . 151

Fig. IT* Method of Hanging Bracket Flume, 152

Fig. 18. Milton Flume, 156

Fig. 19. Profile of Texas Creek Pipe, facing 160

Fig. 20. Lead Joint, 163

Fig. 21. Method of Tightening Leaky Joints, 164

Fig. 22. Elbow for Short Curves in Pipes, 165

Fig. 23. Method of Strapping Elbows and Pipes 165

Fig. 24. Air- Valve for Pipes, 166

Fig. 25. Blow-off for Pipes, 166

Fig. 26. Self-acting Air- Valve, 167

Fig. 27. Profile of Virginia and Gold Hill Water Co. Pipe-Line, . 173

Fig. 28. Profile of the Spring Valley and Cherokee Co. Pipe-Line, . 175 Figs. 29, 30, 31. North Bloomfield Pressure Box, . . . facing 177

Fig. 32. Distributing Gate, 179

Fig. 33. Goose Neck, 180

Fig. 34. Craig's Globe Monitor 181

Fig. 35. The Hydraulic Chief, 181

Fig. 36. The Little Giant 182

Fig. 37. The Little Giant Rifle, 182

14 List Of Illustrations.

Page

Fig. 38. The Hydraulic Giant, 183

Fig. 39. Monitor Hydraulic Machine, 184

Figs. 40, 41. Hurdy-Gurdy Wheel and Derrick-Hoist, . . . 186-7

Fig. 42. The Hurdy-Gurdy Wheel, 188

Fig. 43. Nozzles for Hurdy-Gurdy Wheels, 189

Fig. 44. The Pelton Wheel 193

Figs. 45, 46, 47, 48, 49, 50, 51, 52. Buckets for Hurdy-Gurdy Wheels, 194-7

Fig. 53. The Pelton Wheel, 198

Figs. 54-55. Diagrams showing the Efficiency of the Pelton Wheel, 199-200

Fig. 56. Diagram showing the Comparative Efficiency of Wheels, . 201

Fig. 57. The Rocker 203

Fig. 58. The Tom, 204

Fig. 59. Diagram of Powder Chambers, Smarisville, . 207

Fig. 60. Powder Chambers, Paragon Mine, 209

Fig. 6i. Arrangement of Mines for Firing by Electricity, . . 213

Figs. 62, 63, and 64. Tunnel Sluice Box at North Bloomfield, . 222

Fig. 65. Turn-in Sluice, Patricksville, 228

Fig. 66. Turn-out Sluice-Box 230

Figs. 67, 68, and 69. North Bloomfield Undercurrents, . facing 231

Figs. 70 and 71. Retort 250

Fig. 72. Tail Sluices and Undercurrents, 254-5

Hydraulic Mining in California.

Chapter I. The Records Of Gold-Washing.

The records of gold-washing have been traced al- most to the prehistoric period. If any reliance can be placed upon the traditions which have descended to us, the yield from the auriferous deposits of the ancient world must have been enormous. It is a well authenticated fact that the Greeks carried on from the earliest times an ex- tensive commercial intercourse with the people who lived north and east of the Euxine Sea, and thus drew large- ly on the gold-fields of Siberia, from which source the Gothic tribe of the Massagetae also obtained their wealth. These gold deposits are supposed to have been situated in lat. 53° to 55"" N., and are said to be identical with those worked by the Russians during the present cen- tury.

Asia Minor. — The mountains and streams of Phryga and Lydia yielded gold in ancient times, and history has familiarized us with the wonders of the Pactolus,* from whose famous golden sands Croesus is said to have de- rived his wealth. The sands of Asia Minor long since ceased to yield the precious metal.

Italy. — From a passage in Strabo (book iv. ch. 6, 3ec. 12) it appears that imperial Rome was "inundated with a glut " of gold from her northern mountains, the Alps. Polybius says that in his times gold-mines were so rich about Aquileia . . . that if you dug but two feet

Herodotus, book v. c. lox ; Strabo, book xviii.

I6 The Records Of Gold-Washing.

below the surface you found gold, and that the diggings generally were not deeper than fifteen feet. . . . Italians aiding the barbarians in the working for two months, gold became forthwith one-third cheaper over the whole of Italy.*

Gold alluvia are known to exist in various localities in Upper Italy, but appear to be poor; and at the pre- sent time no gold- washing is carried on, except, perhaps, by a few individual workers. The sands of the Oreo, the Jassin, the Po, and the Serio are estimated to have yielded three hundred ounces of gold in i862.t

Spain and France. — The Romans are stated to have washed the sands of sti eams along the base of the Pyrenees.:}:

The Phoenicians obtained gold from the bed of the river Tagus iioo B.C., and washings are reported along this stream as late as 1833 a.d. The Douro sands were worked for gold by the Arabs until 1147 A.D. Up to the close of the fifteenth century the deposits of the river Arige yielded annually about one hundred pounds of the precious metal. As late as 1846 gold-washings are reported along the Rhine between Strassburg and Phil- ippsburg.

Africa. — At the present time but little gold is found within the limits of Abyssinia and Nubia, though the an- cient Egyptians mined the precious metal in the latter country. The ancient mines described by Lenant Bey are situated in a district called Attaki, or AUaki, between Berenice and Suakin, on the Red Sea, one hundred and twenty miles distant from Ras-Elba. They are spoken of by Diodorus Siculus, and shown on one of the oldest topographical maps extant, preserved in Turin.

Siluria," foot-note, p. 449 ; also Pliny, book iii. c. 6, on the Great Value of the Mines of Italy.

t Report on Precious Metals," W. P. Blake, Paris Universal Exposition, 1867.

X Strabo, book iv. p. 390 ; Caesar, De Bello Gallico," iii. 31 ; Jacob's Inquiry into the Precious Metals," p. 53.

I Sec Agatharchides de Rubro Man," in Diodorus, b. iii. c. i-is ; Account of the Mines in Nubia and Ethiopia" ; also Jacob's " Inquiry into the Precious Metals," ch. xi.

The Records Of Go Ld-W Ashing. Ij

The earliest record of the Egyptian mines dates from the twelfth dynasty. The principal mines of Kordofan are between Darfur and Abyssinia. These mines are mentioned by Herodotus.

Nearly all the gold obtained in Africa has come from alluvial deposits. The country south of Sahara, from the mouth of the Senegal to Cape Palmas, contains numerous gold-bearing alluvions, which arc worked by the negroes. The product of these mines is conveyed by caravans to Morocco, Fez, and Algiers, and forms a principal article of export from the Guinea coasts. Gold-dust is ob- tained also on the southeast coast, between lat. 25 and 22° S., opposite Madagascar, in the country of Sofala, by some writers identified with the region from which Solomon obtained his wealth. Recently alluvial de- posits have been worked in the Transvaal, Leydenburg district (lat. 25° S., long. 35° E.), where coarse nuggets of gold, weighing as much as eleven pounds, have been found.

The approximate gold export of all Africa from 1493 to 1875, according to Dr. Soetbeer, amounted to 106,- 857,000.

India. — In the Bombay Presidency gold-bearing de- posits are reported to exist in the districts of Belgaum, Dharwar, and Kaladgi, in the southern Mahratta country, and the province of Katty war. The sands in the streams arising from the Surtur series are auriferous, as are also those of the river Aji. The central provinces of India contain numerous small deposits of gold, but the number of gold-washings reported is comparatively very limited. The gold-fields of Madras have recently attracted con- siderable attention. The ancient mines of these regions have latterly been rediscovered. The known accumu- lated wealth of the ruling dynasties of southern India is supposed to have been obtained originally from these sources and from Malabar.

Brough Smyth, in his report on the Wynaad gold-

1 8 The Records Of Gold-Washing.

fields, 1879-80, States that the country is covered with tailings, an evidence of the industry of the Korumbas.

In the province of Mysore alluvions (containing very little gold) are known to exist near Betmangla, and gold quartz is being mined at present in different parts of the province.

A number of the rivers which have their sources on the borders of the Champaran district and Nepal, in the State of Travancore, contain auriferous sands, and gold- washing is carried on m these places at the commence- ment and termination of the rains. Auriferous sands oc4 cur in the Kumaun and Garhwal rivers. The sands of the river Koh, near Naginah, in the Maradabad district, are said to contain considerable gold. In Punjab all the riv- ers are reported to contain auriferous sands. Gold-wash- ing has been practised in this district for many years, and was formerly a source of large revenue to the government.

Asiatic Islands. — The sands oi the streams of Cey- Ion, Formosa, the Philippine Islands,* and some of the islands of the Indian Archipelago are known to contain gold ; at Borneo extensive mining operations are carried on by the Chinese and the natives, over thirty thousand of the former being now employed in the gold-fields.

China. — In the beginning of the seventh century the celebrated Chinese traveller, Hiuen-thsang, describes the country north of the Kuen-Lun, towards the desert of Gobi, as an auriferous district. It is either here or in the Thi- betan highlands, east of the Bolor chain, between the Himalaya and the Kuen-Lun, west of Iskardo, that Hum- boldt locates the land of gold sand spoken of by the Dara- das (Dardar, or Derder), mentioned in the Mahabharata, and in the fragments collected by Megasthenes.f

According to Pumpelly :J: gold is found in fourteen out

♦ See Jacobus Inquiry into the Predotu Metals,*' pp. 367-377.

t Humboldt's Cosmos," vol. ii. pp. 5x1-516 ; Jacob's Inquiry Into the Precious Metals,** p. 25.

t Extract Geological Researches in China, Mongolia, and Japan," x86a-65. Raphael Pumpelly. Smithsonian Contrib., Washington, x866.

The Records Of Gold-Washing. 1 9

of eighteen provinces of the empire. The greatest num- ber of washings is in the province of Sze-Chuen (Se- Chuen) and along the branches of the Kuen-Lun moun- tain chain, which have an east and west trend, penetrat- ing into Central China between the Wei River and the Sze-Chuen boundary. Placers are numerous at the base of the water-shed between Kwei-Chow and Hu-Nan, and through the centre of Shantung, from southwest to north- east. Most of these placers furnish coarse gold.

In the province of Shensi, on the northern frontiers at Hopoota and the Hala Mountains, much gold-dust is ob- tained annually. " Hundreds of thousands " of natives find employment in washing the sands of the river Kinsha- Kiang. On the banks of the Lou-tsze Kiang there are numerous gold- washings, and gold is reported to be found in almost all of the streams in the eastern portion of Shan- tung.

Consul Adkins (1877), at Newchwang, reports rich diggings in the valley of Chia-t'i-kou thirty miles long, and about five or six days* journey east by south from Kirwin and Newchwang.

Henry F. Holt's " Notes on Gold in China," published in Lock's work on " Gold," give very interesting infor- mation of the condition of gold-mining in this country, and Pumpelly furnishes a table of the placers.

Japan. — Gold was first discovered in Japan in 749 A.D.,* and the art of mining is said to have been intro- duced from China about the close of the same century. The gold-fields of the Musa valley are reported to have been worked by miners from Chikusen a.d. 1205. Japan has always been represented as a country rich in precious metals. Marco Pplo, in the thirteenth century, said of Zipangu : " They had gold in the greatest abundance, its sources being inexhaustible." " Great abundance " of gold was reported by Kaempfer in 1727. The export of precious metals, chiefly gold, from 1550 to 1639 by the

♦ According to Dr. Geerts.

20 The Records Of Gold-Washing.

Portuguese was about $300,000,000, and from 1649 to 1671 the Dutch traders sent home $200,000,000, two-thirds of which was silver.* In the latter year the Japanese government forbade further export. The maximum gold production of this country was reached during the last half of the sixteenth century. Since that time the yield of gold has decreased steadily, and the product in 1874 is estimated by J. H. Godfrey, Chief Engineer of the Min- ing Office, at 12,000 ounces Troy.

The deposits from which this wealth was drawn were principally shallow placers. Prof. Munroe says that the present gravel-beds in Japan are of fluviatile origin, shal- low, limited in extent, and uniformly poor. The richest deposits, near Yesso, contain less than seven cents per cubic yard, and the average of the best does not exceed five and one-half cents-f

Russia. — Russia possesses extensive gold-bearing de- posits. The principal mining districts are those of the Ural,:|: the Altai region in western Siberia, western Turk- istan, the northern and southern Yeniseisk fields, the cir- cuit of Atchinsk and Minusinsk, Kansk and Nijneudinsk in the government of Irkutsk, Verkneudinsk, Barguzinsk in Trans-Baikalia, Olekminsk, the basin of the Lena, the country along the Amur, and Nerchinsk.

According to Lock (" Gold," p. 437) the total yield of all the Russian gold- washings from 18 14 to i860 mclusive (forty-seven years) amounted to 35,487 poods, or 1,548,661 pounds Troy of alloyed gold.§

In the reports of the United States Commissioners to the Universal Exposition at Paris, 1878, vol. iv. p. 248, James D. Hague states the approximate total production

♦ Griffis Mikado's Empire," p. 602) says that " Japan exported during the sixteenth and seventeenth centuries £103,000,000 in precious metals."

t See " Mineral Wealth of Japan," by Henry S. Munroe, E.M., Trans. Am. Inst. Min. Eng'rs., vol. v.

X Gmelin*8 Journey through Siberia," 4 vols. GOttingen, 1751-a.

I For production of gold in Russia see also Jacob's work, appendix pp. 414, 415 ; Report of the United States Monetary Commission, p. 571 ; Sir Hector Hay's " Parliamentary Re- port on Silver," 1876, App. as.

The Records Of Gold-Washing,

of gold in Russia from 1753 to 1876 inclusive to be $730,- 000,000. He also gives the following table showing the yield of the auriferous deposits during eleven years :

Table L

Years.

No. of Explora- tions.

Quantity of sand and

mineral washed.

Poods.

Quantity of gold ex- tracted. Poods.

Approximate value of product.

968,423.325

1,650

$17,958,600

1,177,288,244

1,711

18,622,524

1,129

1,054,570.392

2,007

21,844,188

1,208

983,475.095

23.476,788

1,081,518,424

2,400

26,121,600

1,055

1,044.027,585

25.370.604

1,018

954,648,764

2,025

22,040,700

1,035

937,578,045

2,027

22,061,868

1,007,293.492

1,996

21,724,464

1,130

1,022,543,362

2,054

22,355,736

2,430

26,448,120

The aggregate of the poods is about 184,000,000 tons of 2,000 pounds avoirdupois, and the corresponding pro- duct is valued at $221,576,472, assuming that the weight of gold given is pure metal.

The Ural.— The gold-fields of the Ural extend from the sixty-first parallel northward about six hundred and ninety miles to the Arctic Ocean, and south into the Cos- sack and Baskir districts. The most valuable deposits have been found in the districts of Miask and Kashgar. At the former the largest nuggets have been obtained, and at the latter emeralds and pink topazes occur asso- ciated with the gold. Near Bogoslolsk is the celebrated mine of Peschanka. The production of these districts has steadily fallen off since i860 — a fact attributable to the impoverishment of the placers, which, nevertheless, are calculated by Bogoliubsky to represent a value of $61,660,000.

The Ekaterinburg group occupies the central UraL The whole eastern slope of the Ural, north and south of

22 The Records Of Gold-Washing.

Ekaterinburg, is auriferous. The principal mine of this district is the Beriozofka, which has produced largely. The first washings were commenced here in 1814, but up to 1 86 1 there was little or no improvement made in the method of working.

In the southern Ural lies the celebrated region of Zlataust, lat, 55° 11' N., long, yf 26' E. The gold allu- vion is found along the lateral streams which feed the Miask. This river was remarkable for its minerals and precious stones. The Miask placers were the richest in the Ural, but of late 3'ears their product has been very small.

The Altai. — Mining in the Altai is said to date from a very early period. The discovery of the alluvial de- posits along the Fomiha River in 1830 gave a new im- petus to gold-mining in Siberia, but richer fields have in later years attracted the miners, and the production of this district appears to have fallen to one-tenth of what it was twenty years ago.

Turkistan. — The auriferous deposits in western Turkistan, along the course of the river Tentek, are said to have been worked by the Chinese. Kuznetsof, a pos- tal contractor, in 1868 tested some old Chinese diggings at Kizil-togoi, but from a summer's work at considerable expense obtained only one pound of gold. This has dis- couraged further mining. It is the opinion of many that the detritus of Turkistan is not at present worth working.

The Northern Yeniseisk. — The northern Yeniseisk fields were discovered in 1832. All the rivers partake of the character of mountain torrents. The most remunera- tive district was discovered in 1839, between the rivers Yenisei and Podkamenny Tungusska.

The Tfeya River is about one hundred or one hundred and fifty feet wide. The gold deposits along its banks have been explored and found too poor to work. On the river Noiba placers were worked in 1842. The country

The Records Of Gold-Washing. 23

was abandoned subsequently, but reopened in 1854. The auriferous stratum lies in the bed of the river, or close to it, and varies in width from one hundred to three hun- dred feet, with a depth of from one to eight feet. These placers now produce annually a large amount of gold.

In the Yenashimo valley the alluvions vary from two hundred to fourteen hundred feet in width, and do not exceed eight feet in depth. They were discovered in 185 1, and up to 1864 produced largely.

As early as 1840 the attention of gold-hunters was at- tracted to the alluvions along the Kalami, a tributary of the Yenashimo, and two years later work was commenced in this valley. These placers were very productive, al- though the auriferous material averages only from two and a half to eight feet in thickness. The mines on the Savaglikon are said to have produced from 1843 to 1864 $25,000,000.

In the valley of the Chirimba several deposits have been washed, and from the beds of the Aktolik a large amount of gold has been produced, the gravel having a depth of from seven to ten feet and varying in breadth, from seven hundred to fourteen hundred feet. Mining operations in the northern Yeniseisk begin in May and continue until about the first week in September.

The Southern Yeniseisk, — In the southern Yeni- seisk gold-fields the rivers have heavy grades. In many districts a scarcity of water prevails during the summer months. Only three of the river basins are noted for their auriferous alluvions, the others holding a secondary rank. The most important valley is that of the Uderey, where extensive gold-placers have been worked since 1845, but are now nearly exhausted. There are nume- rous placers along the river Murojnaia and its tributaries which flow into the southern Yeniseisk fields. The de- posits have been worked since 1841.

The Great Pit River is the administrative boundary between the northern and southern systems. Its length is

24 The Records Of Gold-Washing.

about two hundred and thirty miles, and its valley is from two hundred and fifty to three thousand feet wide. The river in places is very narrow, forming rapids. On the Buruma and the Tujimo, feeders of the Gorbilka, a tribu- tary of the Pit, there were formerly some washings. Below the Gorbilka the Pit is joined by the Penchenga, which, with its numerous feeders, especially the Greater Lower OUonokon, is auriferous. The pay alluvion along the last-named tributary is confined to a channel from fifty-six to one hundred and seventy-five feet wide, and is from eight to twelve feet deep. In general the valleys of the Penchenga are considered too poor to work, though on some ot the feeders washing has been carried on.

On the Untuguna, a feeder of the Ayakta, gold has been washed, and almandines, rubies (poor quality), tour- malines, and an abundance of zircon have been found.

Atchinsk and Minusinsk Fields. — The Atchinsk and Minusinsk fields, which have contributed for many years to the gold production of Siberia, have declined lately in importance.

Kansk and NJfjneudinsk. — Kansk and Nijneu- dinsk, in the governments of Yeniseisk and Irkutsk, for- merly produced a large amount ot gold annually, but of late years their yield has been much reduced.

Verkneudinsk. — The Verkneudinsk district, which is southeast of Lake Baikal, produced up to 1874 some 17,640 pounds of gold, but in 1877 its production was only 480 pounds. North of this field are the auriferous tracts in the basin of the Lena, which have been worked since 1867.

Bargruziusk, Olekniinsk. — The Barguzinsk dis- trict, in Trans-Baikalia, is imperfectly known. The Olek- minsk circuit is situated in the basins of the Vitim and Olekma, tributaries of the Lena, where extensive mining operations have been carried on. This district is one of the most promising centres of gold-mining in Siberia, al- though the climate is very severe and the ground is frozen during the entire year.

The Records Of Gold-Washing. 2 J

Amur. — In the Amur region the gold-mining indus- try has been developed successfully, especially along the Zhya, the Burhya, and the Amgun rivers, but its pro- gress has been checked by the scantiness of population. Two thousand men are said to be employed on the rivers Ura and Oldoi washing the alluvions, which are about seven feet thick. The placers of the Amur basin, in Trans-Baikalia, are a comparatively recent discovery. Gold is widely disseminated along the chief affluents of this river, and the deposits are easily worked.

This basin is reported to have yielded, up to 1875, a profit of ;3, 500,000. The auriferous deposits are esti- mated by Bogoliubsky to be one thousand miles long, three hundred and fifty feet wide, and to average five feet in depth, containing 16 grains per 3,600 pounds. Only one-half of the basin is as yet explored.

Placers are found on the islands in the Sea of Japan, in Str61ok Bay, and along the shore of the Okhotsk Sea.

Nerchinsk. — The placers in the Nerchinsk district are generally frozen. Detritus which yields less than i pennyweight per 1,800 pounds has been found unprofit- able to work.

Brazil. — In 1543 gold was known to exist in Brazil (Walsh, vol. ii. p. loi), deposited in the beds of streams. The Indians at that period are said to have used it to make fish-hooks. Humboldt (" New Spain," vol. iii. p. 401) says that gold-placers were first discovered in 1577. The greatest prosperity of the gold-washings was in the middle of the eighteenth century.

The precious metal was first found in the Riberao, a tributary of the Rio das Mortes, or River of Death. This name commemorates a bloody encounter which took place between the gold-hunters, who, it is said, met and "set upon each other like famished tigers, impelled by the auri sacra fames''

In the vicinity of the Riberao there is abundant evi-

Walsh, Travels in Brazil," vol. i. p. X04.

26 The Records Of Gold-Washing.

dence of the extensive search made for gold. The banks are everywhere furrowed and the vegetable mould has been entirely removed. Nothing remains but the red dirt, cut into squares by channels divided by narrow ridges. These channels were used for washing gravel, and were cut on an inclined plane. The water was intro- duced at the head of them, the dirt was then thrown in, and the lighter particles of clay were washed away, while the gold remained behind.*

The first placers in the country were called cata." The surface dirt which contained gold was mined until the " cascalho," or cement-gravel, was reached. This was broken up by pickaxes, brought to the river, and washed. The first improvement introduced was to conduct the water to the ground and wash the gravel on the spot. These works were called " lavras," and hundreds of them were to be seen on the banks of the Rio das Mortes. A more improved method was practised subsequently. .

In some districts water-wheels were used to assist in the drainage of the excavations, but were found so un- manageable that they were thrown aside, and the negroes were employed to pack off the gravel and rubbish on their heads in small casks.t

According to Dr. Soetbeer, from 1691 to 1875 (one hundred and eighty-five years) the gold production of Brazil amounted to 2,281,510 pounds Troy. By far the greater part was derived from alluvial deposits by river- washing. Harttlj: is of the opinion that there are still extensive surface deposits which, with modern appliances, can be worked successfully on a large scale, and limited washings now occur in almost every province in the empire.

Chili. — Chili contains numerous auriferous deposits, which, according to Schmidtmeyer, extend over most of the coast. The principal deposits are those near Copiapo,

♦ Wabh, vol. ii. p. 105. t Ibid., pp. xia, X13.

% Geological and Physical Geography of Brazil."

The Records Of Gold-Washing. 2/

Guasco, La Ligua, Petorca, Coquimbo, Tiltil, Caren, and Talca. The washings of Aconcagua and La Ligua have been the most productive and extensive. Gold-bearing drift has been reported as existing throughout the south of Chili, fifty miles back from the sea-coast, about the latitude of Coquimbo. Crosiner (Blake*s " Report on the Precious Metals,'* 1867) mentions that gold deposits, which do not appear to have been formed by the de- composition of regular veins, are found in decomposed granite and red clay near Valparaiso. Similar deposits occur along the flanks of the Andes, the most extensive being east of Chilian.

During three hundred and thirty-one years, ending in 1875, the gold product of Chili approximated an annual average of $600,000, principally from the washings of river-beds. Recent attempts by American companies to work the deposits by the hydraulic process have not been attended with success, the yield of gold being much smaller than anticipated and the supply of water being too limited.

Bolivia. — The statistics of Dr. Soetbeer show that from 1545 to 1875 Bolivia produced gold to the amount of 646,800 pounds, or ;4i, 01 3,300, derived principally from the washings of river-beds and shallow placers, the works on the river Tipuani being the most celebrated. The deposits seem to be widely distributed throughout the country, but detailed information concerning them is unobtainablie.

Peru. — In Peru gold was gathered by the Incas in large amounts. Under the Spanish rule more than $33,000,000 arei said to have been extracted from the mines and washings of Caravaya. The discovery of these placers was made in 1 542, and the production of gold from this vicinity continued until 1767, when the town of San Gavan, containing four thousand families and a large treasure, was surprised and entirely destroyed by the Indians.

28 The Records Of Gold-Washing.

In 1849 the attention of miners, was again attracted to Caravaya by reported discoveries of a great abundance of gold in the sands of one of the Caravaya rivers. Num- bers of adventurers visited the country, but returned un- successful. There are gold-washings on the Chaluma River and its tributaries. The region of San Juan del Oro was once famous for its yield. The sands of the tributaries of the Purus are said to contain gold, and those of the Piquitiri are known to be auriferous.

Large deposits were worked with great profit up to 1820 in the province of Parinacochas, department of Ayacucho, along the banks of the Huanca-huanca River.

There are numerous auriferous deposits in the pro- vince of Sandia, department of Puno, some of which have been and still are being worked in a primitive style.

The present condition of the gold regions of Peru is unknown to the world at large. The most definite data of the production of gold from this country are given by Dr. Soetbeer, who says that from 1533 to 1875 the output aggregated ;22,8i 5,225. Paz Soldan*s "Geo- graphical Dictionary of Peru " contains much late infor- mation.

Venezuela. — At Caratal, State of Guayana, in Vene- zuela, small quantities of gold have been obtained from the alluvial deposits. This field has been described mi- nutely by Le Neve Foster, from whose explorations the latest information is obtained. The deposits are situated about a hundred and sixty miles E.S.E. of Ciudad Bolivar. In the valley of the Mocupia gold-washing was carried on as early as 1857. Large placers have been recently discovered about fifty miles northeast of Caratal. The gold product of the Caratal mines from 1866 to 1879 in- clusive is approximated at $14,000,000, and the mining re- gion of Guayana is reported to have produced since 1874 about $1,250,000 annually.

The auriferous alluvions near the river Yuruari and along the banks of the Rio de Santa Cruz have been

The Records Of Gold-Washing. . 29

worked for years by the Indians, and at Tesorero placer- mining is still carried on.

Expeditions from Europe in search of one of the many El Dorados have visited this country and sailed up the Orinoco. Humboldt (" Personal Narrative,'* vol. 3, pp. 23-44) gives an interesting account of this whole matter.

U. S. of Colombia. — The annals of gold-mining in the United States of Colombia are replete with interest- ing information. The famous El Dorado visited by Sir Walter Raleigh in 15 17, and by the buccaneers in the seventeenth century, is situated in the province of Cas- tilla del Oro. The Cana mines of this district, which were, worked by slave labor, yielded largely, accord- ing to tradition, during the seventeenth century. The mines of Choco, on the western side of the Andes, are classed by Schmidtmeyer among the most productive in the west of America. These mines (which contain gold and platinum) are located on affluents of the river Atrato.

The Spaniards in former days carried on extensive mining operations near Malineca, on the river Tuyra. The Mina Real, in the Cerro del Espiritu Santo, at Santa Cruz de Cana, is said to have produced a large amount of gold. Late reports of this mine and mining district are very un- favorable, and cast grave doubts upon the correctness of the statements of its former production.

Auriferous alluvions occur in the vicinity of Piede Cuesta, at the head of the river Lebrija, in the province of Pampluna. All the rivers in Darien which flow directly into the Pacific are said to contain gold. Late reports (1881) state that the sands of the river DibuUa and the Rio de Sevilla are highly auriferous. The rivers of Santiago, Concepcion, Berrera, Zapaterito, San Antonio, and San Bartolomo, which were noted formerly for their gold- washings, continue to the present time to yield remune- rative returns to the miner. Rich alluvions have been lately discovered below the Falls of San Jago, where ex-

30 The Records Of Gold-Washing.

tensive deposits are reported. Dr. Soetbeer states that the gold production of New Granada from 1537 to 1875 was ;i69422,75o.

Mexico. — Cortes exploring parties in Mexico* ob- tained gold from the beds of rivers several hundred miles from the capital. Prescott says that gold, either cast into bars or in the form of dust, was part of the regular tribute of the southern provinces of the empire.f The gold product of Mexico at present is principally from quartz-mines, only a small amount being obtained by the " gambusinos," or native prospectors, who wash with the batea in the placers scattered here and there through the country. There are rumors of large bonanzas in the beds of streams in certain localities, and several attempts have been made to reach this wealth by turning the rivers, but hitherto without success.

The gold in the placers is sometimes distributed in the sands, in small quantities so far as known. In many dis- tricts the gambusinos obtain it, principally from crevices in the bed-rock, to reach which small shafts are sunk, often to a considerable depth.

Australasia. — The most important gold-fields of Aus- tralasia:}: are situated in the colonies of Victoria and New South Wales ; Queensland and South Australia like- wise contain gold alluvions.

Victoria. — The gold product of Victoria, according to the mineral statistics for 1880, aggregated 529,129 ounces, of which amount 299,926 ounces came from the alluvial deposits. Although the old placers have been worked extensively, and exhausted in many cases, the yield has been increased latterly by the opening up of new gold-producing areas and by improved methods of work. The total quantity of gold produced in Victoria from its discovery in 185 1 to the end of 1880 is placed officially at

See Helps, " Spanish Conquest of America" ; also Las Casas, " History of the Indies." t Prescott's "Conquest of Mexico," vol. i. p. 139.

t See " Gold," by A. G. Lock, from which work the above notes on Australasia are condensed.

Xhe Records Of Gold-Washing. 3 1

;f 198,196,206, the mining operations extending over an area of twelve hundred and thirty-five square miles.

Ararat district contains large deposits of the upper and newer pliocene, considered to be of marine origin, but no gold in workable quantities has been found in any of these beds. The workable placers occur in the lower newer pliocene, whose origin is clearly a result of fluvia- tile agency. A fact worthy of mention is that in the neighborhood of Ararat, so far as yet explored, not a single well-defined quartz-vein has been found to contain pay gold.

In the northern portion of the Ararat fields the de- posits attain a depth of from ninety to one hundred and fifty feet. In the Great Western mine the deposit, com- posed of older pliocene gravel-drift resting upon disinte- grated granite, has been mined for a length of two miles and a width which in places exceeds twelve hundred feet. From accumulations of saline waters, and from undula- tions both horizontally and laterally of the bed rock, it is considered that the lead " is simply a depression in a former sea-bottom.

In the Ballarat fields there are four clearly defined epochs of gold-drift, whose relative local positions are in- dicated by their names : " Oldest," " Older," " Recent," and " Most Recent." The Oldest " period includes a deposit antecedent to the time at which the channels were eroded to their present depth. The " Older " embraces the deposit intervening between the lava-flows. Deposits of "Recent" age are those following immediately the uppermost lava-flow. " Most Recent " drifts are those in most recently eroded gullies. There are three great lead systems near Ballarat, called the " Southern," " Western," and " Eastern." The Southern " has been explored ex- tensively ; the " Western " is looked upon by some as the future hope of Ballarat in alluvial mining ; the " Eastern " is but little known.

The alluvial deposits in Beechworth district have been

32 The Records Of Gold-Washing.

derived from the Silurian strata, not from the granite. The mining operations practised are simply those of ground-sluicing on a large scale. Considerable work has been done on the placers in Dargo district. The thick- ness of the gravel is from thirty to forty feet. On Mitchell River the gold-workings are confined to the creeks and the older alluvions on the banks. The Wa- ranga fields, Sandhurst district, are among the oldest Vic- torian gold-fields, and have been worked since 1853. The most important of the workings are in the vicinity of Rushworth on a cement deposit, probably of the older pliocene. The gravel is shallow, the deepest shafts being only from thirty-five to fifty-five feet. This lead has yielded more than any other in the district. Nuggety Gully, Cemetery Lead, and Coy Diggings are also placers of note.

New South Wales.— The auriferous districts of New South Wales are considered the richest and most extensive in Australia. The gold-fields extend, with short intervals, the entire length of the colony, with a breadth of two hundred miles. Immense tracts in the in- terior still remain unprospected, and in time may prove to contain valuable gold-bearing deposits. Up to 1871 alluvial washings alone were carried on, gold-quartz min- ing being neglected. At this period sixteen thousand miners were at work. The product from 1851 to 1871 inclusive is stated by Reid to have been ;£'26,457,i6o. The gold regions are all easy of access and are within two days* journey of the capital.

In Bathurst, Tambaroora, Turon, Lachlan, Mudgee, Southern, Peel, and Uralla districts water is scarce, and the discoveries of gold at Temora, Montreal, and Mount Browne have attracted a large number of miners from these places. Water is scarce at Temora also, but for- tunately a large amount of very coarse gold has been found. The Montreal placers are near the sea-coast. The deposits are said to occur in two terraces, and give evi- dence of having been washed back by the sea.

The Records Of Gold-W Ashing. 33

In 1880, of the 13,430 gold-miners in the colony of New South Wales 11,403 were engaged in alluvial mining.

The Barrington field, on Back Creek, is about ten miles from the town of Gloucester. The principal gold deposits occur amid steep ranges, covered with thick forests and dense undergrowth. The creek has been worked for gold, but the results, though profitable, have not been remarkable. The water supply is very uncer- tain, and in summer the creek ceases to flow.

The Kiandra gold field, on the table-land of Maneero, is situated about five thousand feet above sea-level, close to the highest mountains in the colony, around which are extensive deposits of auriferous gravel. Near Mount Table-Top the alluvions have been covered with basalt, and up to the present time this main deposit has been worked only to a limited extent.

The chief localities in which gold-mining has been carried on are those of Nine-Mile Diggings, New Chum Hill Diggings, Scotchman's Tunnel Claim, Bullock- Head Creek, and the Eucumbene River ; also Township Hill Diggings, Eight-Mile Diggings, and Fifteen-Mile Dig- gings. Recent surveys show that water can be brought on certain of the Kiandra diggings, and here hydraulic mining is possible on a very limited scale. The rich placers developed by the sluicing operations toward Mount Table-Top have been compared by some writers to the gravel deposits near Placerville, California. Lach- Ian district was partially developed in the rush of the first mining excitement, and it is believed that only an insig- nificant proportion of the ancient river deposits was worked by the early miners.

Mount Werong is the site of one of the recent discov- eries. The auriferous alluvion is said to be widely scat- tered. The gold has a water-worn appearance, and it is supposed that an old channel or lead formerly existed here. But as yet the country is only partially explored.

The Tallawang field contains one of the most ancient

34 The Records Of Gold-Washing

auriferous alluvial deposits in the world ; the gold occurs in the tertiary alluvial deposits, and in conglomerates in the coal measures the precious metal has also been lound in paying quantities. At Clough's Gully the conglome- rate is being worked and yields from i to 15 penny- weights per ton, and nuggets of 5 ounces are occasionally lound.

Queensland. — The colony of Queensland lies to the north of New South Wales. Here thirty-one hundred square miles of auriferous alluvial and quartz ground were worked upon in 1876. The gold-fields occur on both sides of the main dividing range which separates the eastern and western waters, and on the spurs of the range which forms the water-shed to the Gulf of Carpentaria.

Charter's Towers fields are situated about the centre of the eastern portion of the colony. There are several small alluvial deposits, but the principal industry is that of gold-quartz mining.

In the Gympie district extensive quartz-mining is carried on, and some alluvial gold has been found in the Marengo gullies.

Gold quartz is mined in the Normanby region, but alluvial gold is sparsely distributed, the deposits not pay- ing the cost of labor.

South Australia. — In South Australia gold is found in nearly every part of the colony, but the deposits are of very limited size. The bed of the river Torrens has yielded small quantities. The deposits of Barossa are said to resemble geologically and topographically Ben- digo and other Victorian fields where the basaltic lava is absent. The principal deposit is probably of older plio- cene age. The main lead in Spike's Gully shows a drift varying from twenty to a hundred feet in depth. In this drift, which consists of quartz pebbles, boulders, and ferruginous conglomerate, the gold is water- worn. The topography of the country is favorable for the construc- tion of reservoirs at small expense, and sluicing could be

The Records Of Gold-Washing. 35

introduced without difficulty. The Echunga fields were discovered in 1852, but gave employment to a small num- ber of gravel-miners only. Cement-crushing has been carried on in this district, but with little success. The Ulooloo gold-field contains some auriferous deposits com- posed of clay, sand, and shingle, forming banks of from six to twenty feet along the Ulooloo Creek. Water, however, is here very scarce.

In the northern territory, which extends from the Sta- pleton to the Driffield rivers, the auriferous deposits have been explored for a distance of about one hundred miles in length by twenty miles in width. There are no drift deposits. The alluvial gold occurs in small gullies and ravines, and occasional rich pockets are found.

New Zealand. — Gold was discovered in New Zea- land in 1842. The alluvial deposits occur chiefly in the South Island, in the districts of Otago, Westland, and Nelson, where mining operations are carried on over an area of almost twenty thousand square miles. The de- tritus is found in the beds of the rivers, in large deposits of gravel from three hundred to five hundred feet deep, and in the sands along the sea-shore. The gold-drifts in Otago rest on the denuded surface of the parent rock, while in the Westland district they lie on tertiary rocks of marine origin. Fully two-thirds of the gold returned from this country is obtained from alluvial mining. The extent to which work is carried on may be judged from the fact that the miners have constructed over five thousand miles of water-races, with attendant tail-races and dams, at a cost approximating ;£'300,ooo ; this is in- dependent of the government water-races and dams, which have cost ;45o,ooo.

Ground-sluicing is practised, and in some instances hydraulic mining has been introduced with heads of water from eighty to one hundred feet. The government has a tunnel eleven feet by seven feet, five thousand seven hun- dred and forty-four feet long, in course of construction,

36 The Records Of Gold-Washing.

having already built the open Sludge-channel, eight miles long, at Naseby. Besides these several tunnels have been built by private individuals.

At Gabriel Gully, Tuapeka, where the grade is very light, the hydraulic elevator is said to be working succes- fuUy ; and in the river Clutha dredging machines are at work on the auriferous deposits. North of Charleston, on the coast-line, the beach sands which contain gold are worked by a colony of Shetlanders.

Extensive sluicing operations are carried on along the banks of the Molyneux, Kawarau, and Shotover rivers. At Tinkers and Drybread Diggings forty sluice-heads of water, with one hundred and thirty feet head, conducted through forty-five hundred feet of iron piping, are used to hydraulic the gravel. The depth of the deposits on the so-called Maori bottom approximates thirty feet. The resources of the province in auriferous drift are very great. Ulrich considers part of the old Clutha Lake basin where Bendigo Cre'ek enters, and along the foot of the range upon which Bendigo reef occurs, as especially worthy of the attention of the drift-miner, liller's Flat, between Arrow and Queenstown, a supposed old river- channel, is also considered rich.

The Thames field, on the east side of the Hauraki Gulf, is a narrow strip of land twenty-five miles long and from two to four miles wide. The gold in this district is obtained chiefly from quartz reefs. In Tapu district gold is found in considerable quantities in the decomposed soil on the slopes of the hills. It is usually flaky and not at all water-worn.

In Westland district the mines are classed as cement and alluvial workings. The cement is from one to six feet in thickness, and consists of quartz gravels which are found in connection with the coal series. The gold oc- curs in the lower portion of these beds. Alluvial work- ings are met with in all gillies cut in the auriferous series, but the gold is generally coarse. In the con-

The Records Of Gold-Washing. 3/

glomerate formation the gold is caught in the brown sandstone bottom over which the conglomerate lies.

In the glacial drifts extensive claims have been worked and large quantities of gold have been obtained. These deposits are interesting, inasmuch as they derive their gold, in all probability, from the slates of which the glacial drifts are composed.

The black-sand beaches are composed of crystals of magnetic iron ore, which are found disseminated through the chloritic schist. The gold which is associated with the sand is supposed to have been derived from the Maitai slates, brought down in immense quantities by glaciers. This district includes the gold-fields of Waka- marina. Queen Charlotte Sound, and VVairau valley.

Extensive sluicing is going on at present in Waka- marina district. The ground is spotted and the gold is distributed unevenly. The Queen Charlotte Sound field is a quartz-mining district. The Wairau valley is an al- luvial deposit, and is a comparatively new district. Gold occurs in almost all the gullies on the north bank of the Wairau River. The gullies are all very narrow. Some of the claims have proved very rich.

Canada.— In Canada gold is derived from the de- gradation of the upper Silurian and Devonian rocks. The Geological Commission, as early as 1852, determined the existence of auriferous alluvions extending over an area of more than ten thousand square miles. The prin- cipal deposits explored have been in the province of Quebec and in Nova Scotia. As notable may be men- tioned the workings along the Chaudire River and its tributaries, the Du Loup and the Gilbert. Extensive deposits occur also to the southeast of the Notre Dame Mountains.

Small local deposits of high value have been worked, giving rise to great expectations, but as a whole the re- sults have been unsatisfactory.

British Columbia.— In British Columbia gold was

38 The Records Of Gold-Washing.

discovered in 1858 on the Frazer River, above New West- minster, causing a great excitement and a " rush " of pros- pectors. San Francisco was nearly depopulated by the exodus, and it is estimated that one-sixth of the voters of California moved to the new placers. Gold was traced three hundred miles up the river to Cariboo. On the Peace River, two hundred and fifty miles still further north, gold was found. In 1872 discoveries in Cassiar district, eight hundred miles north of Victoria, caused the " Stickeen River rush." The Frazer River deposits were remunerative only to a limited extent and were soon worked out. In all the localities in this country the workings have been principally confined to shallow placers and river-bars, which are soon exhausted ; but at Cariboo there are channels beneath the beds of the present water-courses. Shafts are sunk from the sur- face to the auriferous channels through a covering of clay and gravel. The bed of the ancient stream, when reached, is followed by drifts. While handsome returns have been occasionally made (in 1861 nearly a million of dollars were extracted), the expenses of working, there being much water to contend with, are so large that the operations have almost entirely ceased. In the more northerly districts the climate presents great obstacles and work can be carried on only during a few months of the year.

In Vancouver Island, in the Leech River district, gold has been found in a small area some twenty miles from Victoria.

Lock estimates that from 1858 to 1880 (twenty-two and a half years) gold of the value of $45,140,889 has been extracted from (principally) the alluvions of British Co- lumbia.

United States of America. — Outside of California (which will be treated in the following chapter), up to the present time, the alluvial deposits worked have been prin-

♦ " Gold," p. 38.

The Records Of Gold-Washing. 39

cipally shallow, and continued profitable development on a large scale is unknown.

New England.— Gold has been found in Vermont and New Hampshire, and alluvial deposits of limited ex- tent have been exploited along the Green Mountains. But the production has been comparatively insignificant.

Virginia. — Alluvial gold has been reported as found in Virginia in Montgomery and Floyd counties, along Brush Creek. In Goochland County the hydraulic pro- cess was tried in 1877.

Norili Carolina, Soutli Carolina, Georgia. — The Appalachian gold fields extend through the States of North Carolina, South Carolina, and Georgia. Gold was first discovered in 1799, and in 1829 the discovery of pla- cers caused a great excitement. Two principal belts are known in North Carolina, one extending through Guilford, Davidson, Rowan, Cabarrus, and Mecklenburg counties ; another through McDowell, Burke, and Rutherford coun- ties; the latter has been traced mto northern Georgia, where it forms the gold region in the vicinity of Dahlo- nega. The latter is the more western and more elevated, and contains richer placers.

The formation of these gold deposits has been attri- buted rather to the action of atmospheric influence than to deposition by large streams. The best placers were exhausted at the time of the discovery of gold in Cali- fornia, and more recent attempts to work them on a large scale and by the hydraulic process have not met with success.

Idalio. — Gold was first discovered in paying quan- tities near Pearce City, Idaho, in i860. The Territory of Idaho, then a part of Washington Territory, was organized in 1862. The principal placers were those in the Boise basin, which first attracted the attention of miners in 1862, and on the Snake and Salmon Rivers. In 1865 the production of gold in the Territory amounted to $8,023,680, but the yield gradually decreased from that

40 The Records Of Gold-Washing.

year, and the placers produced in 1880 only $879,644. The Boise basin has been nearly exhausted, and the lower Snake River bars, which are quite limited in extent, are practically deserted. Above Fort Hall work is still go- ing on. Salmon River was abandoned to Chinese labor in 1870.

Montana. — Gold was found on Gold Creek, in Deer Lodge County, Montana, in 1852, but the developments did not attract much attention until 1862, when a rush of immigration took place. The yield of the district up to 1870 is estimated at $24,000,000. Extensive works are still being carried on in this county. In Lewis and Clarke County the gulches and foothills are known to be aurife- rous to a great extent ; they have yielded and are still yielding large amounts of the precious metal. Alder Gulch, in Madison County, was discovered in June, 1863, and in three years is said to have produced $30,000,000 (Raymond's "Report,** 1870). Work is prosecuted still in this county and also in Meagher County.

Montana has contained some of the richest deposits known. Most of these have been worked as shallow pla- cers, and in many of the locations much trouble has been experienced in obtaining water.

New Mexico.— Gold-placers are 'known to exist in New Mexico along the Rio Grande, from the Colorado line to the placers some forty miles south of Santa F6, and also in the southwestern part of the Territory in the counties of Dofia Ana and Grant. The latter have not been opened up to any great extent, although reports of exceedingly rich placers have long been current. The de- posits along the Rio Grande have been described by Ray- mond Mineral Resources, 1874**) and Prof. Silliman The Rio Grande Gold-Gravels who are authorities for the following statements.

The auriferous gravels extend southerly from the Colo- rado line along the Rio Grande valley some one hundred \nd fifty miles, over a width of about forty miles, between

The Records Of Gold-Washing. 4I

the Sangre de Cristo Mountains on the east and the Con- tinental Divide on the west. The southern portion, say seventy-five miles in lineal (northerly and southerly) ex- tent, has been extensively denuded. The more northerly area has been eroded more or less, and contains accumu- lations of gravel, varying from fifty to six hundred feet in depth. Overflows of volcanic rocks cover and protect or interstratify the gravels in very many instances. The gravel consists chiefly of quartz and quartzite, and, to a much less extent, of syenite, porphyry, granite, gneiss, and slate debris, and evidently has been carried to its present location from only a short distance, probably from the Archaean rocks of the Sangre de Cristo and other souther- ly ranges of the Rocky Mountains. The gold is said to be dififused through the alluvions with great uniformity.

South of Santa F6 large Mexican grants contain ex- tensive deposits of gravel, where gold was discovered in 1842, and whence in succeeding years large amounts of the precious metal are said to have been extracted. Ame- rican companies have been recently formed to work all these deposits along the Rio Grande, but thus far the ob- stacles to success seem to have been very great.

Other States and Territories. — In various other States and Territories, as Colorado and Dakota, placer- mining has been carried on by small companies on a limit- ed scale.

Chapter Ii.

History And Development Of Placer-Mining In California.

From the auriferous deposits of the State of California $1,100,000,000 have been extracted during the last thirty- five years.*

The magnitude of the mining operations required to produce this enormous yield is but little known to the general public. The continuous flow of gold bullion has, however, made the State famous and attracted the atten- tion of political economists everywhere.

First Mention of Calilbrnia.— The first mention of the name "California" occurs in connection with a supposed great island where gold and precious stones were found in abundance, described in a romance called Las Sergus de Esplandian," pubhshed in Spain a.d. 15 10. The followers of Cortez had chimerical ideas of some hidden El Dorado, and, strange to say, they applied the name California to that unknown country north of Mexico with which they associated the notion of a region of fabu- lous wealth.

Discovery of Lower California.— The first expe- dition sent out by Cortez, in 1534, discovered what is now called Lower California. According to Father Venegas, this expedition, numbering some seven hundred souls, was fitted out at the port of Tehuantepec in the year 1537, and sailed north to the head of the gulf of California, but never reached the line which marks the southern boun- dary of the State of California.

Contemporaneously with the departure of this party " four persons, named Alvarez Nufiez, Cabeza de Vaca,

Up to 1883. See Appendix A.

History And Development Of Placer-Mining. 43

Castillo, and Dormentes, with a negro named Estevancio/* arrived at Culiacan, on the gulf of California, from the peninsula of Florida. These were the sole survivors of the three hundred Spaniards who in 1527 landed with Pamfilo Narvacz on the coast of Florida with the inten- tion of conquering that country. Nufiez subsequently conducted the expedition which discovered the Rio de la Plata and effected the first conquest of Paraguay.

Early Exploratiofas' — In 1542 Mendoza,' Viceroy of Mexico, sent Rodriguez Cabrillo, a Portuguese, to sur- vey the west coast of California. He explored the coast, naming the numerous headlands, the most northerly of which, in lat. 40° N., he called Cape Mendocino. Thence he proceeded further north to lat. 44, which he reached March 10, 1543.

In 1578 Sir Francis Drake entered the Pacific and sailed north as high as lat. 48°. According to Hakluyt's account of the voyage, Drake spent five weeks in June and July, 1579, in a bay near lat. 38° N.

First Mention of Gold,— The narrative says: " Our General called this country New Albion. . . . There is no part of the earth here to be taken up where- in there is not a reasonable quantitie of gold and silver." It is difficult to reconcile this statement with the facts as known at present, since in lat. 38° N. neither gold nor silver exists in reasonable quantitie " near the ocean. This is, however, remarkable as the first mention of gold in California proper.

In 1602 the Count de Monte Rey, Viceroy of New Spain, by order of the king, sent Sebastian Viscayno on an exploring expedition. He sailed from Acapulco, May 5, 1602, with two vessels and a tender, with Admi- ral Gomez in command. The expedition, composed of a large number of men, was fully equipped for one year's voyage. Three barefooted Carmelites accompanied the party, and the several departments were entrusted to dis- tinguished officers, volunteers from Brittan3\

44 History And Development

After a struggle with northwest winds, on November lo, 1602, the fleet entered the harbor of San Diego and, having spent a few days there, the expedition again sailed north. December 16, 1602, anchor was cast in Monterey Bay, which was named in honor of the viceroy. January 3, 1603, the fleet weighed anchor, and a period 01 one hundred and sixty-six years elapsed before this bay was revisited. January 12 the fleet passed the bay of San Francisco and anchored behind a point of land called " La Punta de los Reyes," but did not enter San Fran- cisco harbor. The voyage was subsequently continued as far as lat. 43° N., from which point the fleet returned to Acapulco.

First Mission established in Lower California. — In 1697 the first permanent mission was established by the Jesuits at Loreto, Lower California. " These people," says the historian, " with patient art and devoted zeal, accomplished that which had defied the energy of Cortez and baffled the efforts of the Spanish monarchy for gene- rations afterwards."

First Mission in Upper California.— In 1769 the Jesuits were banished from Lower California. On the 9th day of January, 1769, an expedition set sail from La Paz, in Lower California, to rediscover San Diego and Monterey. The vessels stopped at Cape St. Lucas, and left that point February 15 of the same year. On the 1st of July, 1769, a land expedition which had started shortly after the vessels had set sail from Cape St. Lucas, under the immediate charge of Padre Junipero Serra, reached San Diego and established the first Franciscan mission in Upper California.

Notwithstanding the facts revealed by the many ex- peditions, the geographers of that day still persisted in describing California as an island extending from Cape St. Lucas, at the tropic of Cancer, to lat. 45®

An interesting account of this voyage is given by E. Randolph, Esq., " Memoirs of the Society of California Pioneers."

Of Placer-Mining In California. 45

N.,* and it was not until Father Begert's map was pub- lished at Maziheim, in 1771, that California was relieved of its insulai character.

Early Discoveries of Placers.— At different times between 1775 and 1828 small deposits of placer gold were found by Mexicans near the Colorado River. In 1802 a mineral vein supposed to contain silver was found at Olizal, in the district of Monterey. In 1828 a small gold placer was discovered at San Isidro, in what is now known as San Diego County.

Forbes, in his history of California, in 1835, says: "No minerals of particular importance have yet been found in Upper California, nor any appearance of metals.**

In 1838 the placers of San Francisquito, forty-five miles northwest from Los Angeles, were discovered. These deposits were neither rich nor extensive, but were worked steadily for twenty years.

In 1841 Wilkes* exploring expedition visited the coast, James D. Dana, mineralogist, accompanying the party. In the following year, in his work on mineralogy, Dana mentions that gold was found in the Sacramento valley, and that rocks " similar to those of the auriferous forma- tions were observed in southern Oregon.

May 4, 1846, Thomas O. Larkin, United States Consul at Monterey, said, in an official letter to James Buchanan, Esq., then Secretary of State : " There is no doubt that gold, silver, quicksilver, copper, lead, sulphur, and coal mines are to be found all over California, and it is doubt- ful whether, under their present owners, they will ever be worked.**

On the 7th of July, 1846, the American flag was hoisted at Monterey and the country taken possession of by the United States.

Ogilvy*s America: being the latest and most accurate Account of the New Worid/' published in London in 1671. California b there laid down as an island, extending fiom Cape St. Lucas to lat. N. See map by Capt. Shelvockef R.N., Voyage around the World by way of the South Sea," published in Indon in 1736. See map published ia Venice in 1546, Independent Order of Odd Fellows' Hall, San Francisco.

46 History And Development

Marshall discovers Gold at Coloma. — January 19, 1848, James W. Marshall, while engaged in digging a race for a saw-mill at Coloma (thirty-five miles east from Sutter's Fort), found some pieces of yellow metal which he and the half-dozen men working with him at the mill supposed to be gold. " He felt confident that he had made a discovery of great importance, but he knew nothing of either chemistry or gold-mining, and he could not prove the nature of the metal or tell how to obtain it in paying quantities. ... So Marshall's collection of specimens continued to accumulate, and his associates began to think there might be something in his gold-mine after all."

In the middle of February, Bennett, one of the party employed at the mill, went to San Francisco and returned with Isaac Humphreys, a man who had washed gold in Georgia, and who, after a few hours' work, declared the mines to be richer than those of his own State. By means of a rocker he obtained daily about one ounce of gold, and soon all the hands of the mill were rocking for the precious metal.

The record of the discovery of gold, as related by Parsons in his biography of Marshall, is somewhat dif- ferent from that published by Browne, and gives to Mar- shall alone the credit of the discovery.

Other Gold Discoveries.— Pierson B. Redding, the owner of a large ranch at the head of the Sacramento valley, visited the mining works at Coloma, and imme- diately resolved to commence washing on. his own pro- perty, which he thought was in a similar formation, and in a few weeks he had begun mining on a bar on Clear Creek, nearly two hundred miles northwest from Coloma. This example was followed by John Bidwell, who, having seeh Sutter's works, commenced prospecting on the bars of the Feather River, seventy-five miles northwest from Coloma.

See Reports upon the Mineral Resources of the United Sutes,** by J. Ross Browne, 1867.

Of Placer-Mining In California. 47

In March, 1848, the treaty of Guadalupe-Hidalgo was made, and Mexico ceded California to the United States. By the end of the same year mines were opened at far- distant points. Miners were at work in every large stream on the western slope of the Sierra Nevada, from Feather River to the Tuolumne, a distance of one hun- dred and fifty miles.

First Publication of Gold Discoveries.— The first printed notice of the discovery of gold appeared in the Calif ornian (?), a newspaper published in San Fran- cisco, on March 15, 1848. On May 29 the same paper announced that its publication would be suspended, the whole population having betaken itself to the mines.

In 1849 the placers of Trinity and Mariposa were opened. At this period hired men were the exception, every man working for himself, and rocker claims were very abundant. In 1850 the deposits of Klamath and Scott's Valley were discovered.

First Attempt to build Ditches. — The chief want of the placer-miner being water, the first noteworthy attempt at ditch-building was made in March, 1850, at Coyote Hill, Nevada County.

In the spring of the same year gold was reported as lying in heaps on the banks of Gold Lake, near Downie- ville. This caused a tremendous excitement and a rush of miners to that locality. In a few weeks thousands re- turned from the lake poorer than when they started.

On September 9, 1850, California was admitted into the Union as a State. The number of persons then en- gaged in mining was estimated at fifty thousand. River- mining at this period occupied a prominent place in the industries of the State.

First Use of the Long Tom/'— The winter of 1849-50 was very stormy and comparatively little work was done in the rivers or creeks, but in the spring of 1850 mining was resumed on those bars which were subject to overflow only at extreme high water. The pick, shoveU

48 History And Development

rocker, and wheelbarrow were the only implements then in use. Towards the end of 1850 the "Long Tom" was introduced.

Discovery of Gold-Quartz Veins. — Extensive pros- pecting at this period for the sources of these gravel de- posits led to the discovery of gold-quartz veins, the most noted of which was the Allison Ranch mine in Nevada County. In 1851 came the rush to Gold Blufif, lat. 41° N.

The work on dry bars gradually led to mining the river bottoms, which was first undertaken by means of wing dams. Later the more venturous miners turned entire streams from their courses by means of flumes or ditches.

First Working of Deep Deposits. — Simultane- ously the miners " pushed back " from the shallow placers to deep deposits which were worked by means of the tom, and with the advent of sluices in 1851 the low hill gravels were attacked and successfully mined. Coincident with the introduction of the sluice and washing of hill gravels came the employment of hired men in placer diggings.

Slnieing. — The deep deposits of auriferous gravel were relatively poorer than the shallow placers, and open cuts, preparatory to sluicing, were requisite ; a large sup- ply of water was a sine qua non ditches became a neces- sity, labor was in demand, but without capital nothing could be accomplished.

The sluice revolutionized gold-washing. With the ex- haustion of the surface diggings the river towns fell into decay, and those mountain districts where the deep auri- ferous beds were found soon became the prosperous coun- ties of the State.

First Use of tlie Hydraulic Metliod.— It was evident that the sluices ran dirt faster than the shovellers could supply it; labor was expensive — men receiving from $6 to $8 per diem — and the claims were poor com- pared with the washings of 1849-50. In 1852 Edward E. Mattison, of Connecticut, with a view to economizing

Of Placer-Mining In California. 49

labor, used a stream of water under pressure. For this purpose water was conveyed to the claim in rawhide hose and discharged through a wooden nozzle against a bank. Tom by the water, the earth was carried into the sluices and shovelling was thus avoided. A large saving in the cost of mining was effected, a greater amount of material being washed in a shorter time. This was the first step in hydraulic mining.

Canvas Hose* — Mattison's experiments were imme- diately appreciated and his method adopted. Hose made of canvas was widely used, the canvas being strengthened by netting and bound with rope.

Iron Pipe. — Towards the end of 1853 pipes made of light sheet iron were introduced as a substitute for canvas hose. The first iron pipe was used by R. R. Craig, on American Hill, Nevada County. It consisted of about one hundred feet of stove-pipe. In 1856 a firm in San Francisco commenced the manufacture of wrought iron pipes for hydraulic mining, and during the years 1856 and 1857 large sheet-iron pipe forty inches in diameter was laid for a water-conduit across a depression at Timbuctoo, in Yuba County.

Inverted Siphons. — In 1869 a wire suspension bridge across the Trinity River, near McGillivray's, was constructed by Joseph McGillivray. This bridge sup- ported a fifteen-inch wrought-iron pipe which conducted water from a ditch situated at an elevation of about two hundred and forty feet above the bridge. The length of the pipe was nineteen hundred and eighty feet, and the outlet was one hundred and thirty-three feet below the level of the inlet. In the fall of 1870 the Spring Valley Company, of Cherokee, Butte County, laid the first large " inverted siphon in the mining regions. The siphon was made of wrought iron, riveted. It was thirty inches in diameter and fourteen thousand feet long, crossing a de- pression of nearly one thousand feet.

ImproYed Nozzles. — With the substitution of sheet-

50 History And Development

iron pipe for canvas it was found necessary to retain a short piece of canvas hose in order to obtain a flexible dis- charge piece. This was inconvenient and troublesome. The ingenuity of miners was aroused, and the result was the introduction of a nozzle called the Goose Neck, which was a flexible iron joint formed by two elbows working one over the other.

The first Rifle. — The radius-plate, or rifle, was pat- ented by C. F. Macy in 1863, and was subsequently intro- duced and used in all metallic jointed discharge pipes which had elbows.

The next improved hydraulic nozzle was invented by the Messrs. R. R. & J. Craig, of Nevada County. It was called Craig's Globe Monitor. This nozzle proved a suc- cess and was adopted at once by the miners. Subsequent- ly the Hydraulic Knuckle-joint and Nozzle was invented by H. Fisher, of Nevada County, and took the place of the Craig machine. In 1870 Mr. Richard Hoskins ob- tained a patent for his Dictator, a one-jointed machine, having an elastic packing in the joints instead of the metal- lic faces. A few months later Hoskins patented the noz- zle called the Little Giant, which was an improvement on the Dictator, and has to a great extent superseded the older inventions.

Deflector. — The next advance in hydraulic discharge machines was an attachment to the nozzle called the deflector,** the invention of Mr. H. C. Perkins, and pat- ented May, 1876. This is a short piece of pipe, about an inch larger in diameter than the nozzle, attached to the latter by a gimbal joint and operated with a lever. This improvement has been followed by the invention of the Hoskins Deflector. This latter is a flexible semi-ball joint between the end of the discharge pipe and the nozzle. It is operated by a lever.

In 1852 and 1853 placer-mining was at the height of its prosperity. Labor was well paid, and employment was easily obtained by all who sought it. At this period

Of Placer-Mining In California. 5 1

there still remained a few of the rich surface deposits which had formerly been so numerous.

First Driflt-Minliig,— The first extensive drift-min- ing in the old river channels was commenced in 1852 at Forest Hill, Placer County; though in 1851 a surface claim at Brown's Bar, on the Middle Fork of the Ameri- can River, was drifted out by Joseph McGillivray.

In 1854, in consequence of the reported discovery of gold-diggings in Kern County, California, numbers of miners flocked to the southern part of the State, only to find there poor deposits of a very limited area.

Table Mountain. — Some miners engaged in sinking a shaft near Jamestown, Tuolumne County, where the gravel had been washed away, discovered gold at Table Mountain. Simultaneously other miners traced a seam of gravel containing gold along its sides, and it was found that this seam ran into a deep, rocky channel lying under the mountain. The presence of water in great quantity frustrated all attempts to work this deposit.

Deep Tunnels. — Further explorations developed the existence of channels running under this ridge, which were found to have a westerly course and to pitch deeper as work advanced. After several ineffectual attempts to drain the deposit, the gravel, which proved later to be exceedingly rich, was finally bottomed by a deep tunnel. " Ten square feet, superficial measurement, yielded $100,- 000, and a pint of gravel not unfrequently contained a pound of gold.*'

An impetus to deep gravel mining or drifting was given by these developments, and extensive explorations of a similar character were undertaken subsequently in other parts of the State.

During the years 1856 and 1857 river, bar, and gulch mining were less productive, but quartz and ditch inte- rests became more valuable.

The Frazer River excitement of 1853 caused a stam-

See Ross Browne, Reports on the Mineral Resources of the United States," 1867.

52 History And Development Of Placer-Mining.

pede of miners and speculators to British Columbia. The subsequent developments of these gravel fields occasioned loss to those who had been attracted thither by the desire of gain.

In 1859-60 came the exodus to the Comstock, and in 1862 the rush to Idaho followed.

Hydraulic mining gained ground steadily from 1852 to 1865. As the river bars and surface diggings one after another were exhausted, the working of the old river de- posits by the hydraulic process became a necessity. At the present time it is by this modern method of mining that the bulk of the gold of this State is produced, and in this business nearly $100,000,000 of capital are invested.

The hydraulic process is now carried on upon such a gigantic scale and to so vast an extent as to require the assistance of the science of hydraulics and engineering. Heretofore, apart from the construction of ditches and tunnels necessary for washing the gold-bearing dirt, en- gineers have had but little to do with the management of hydraulic claims.

The primitive placer-mining of 1852 to 1865 has passed into history. Forty-inch wrought-iron pipes have been substituted for canvas hose and stove-pipe, and with the replacing of one-inch streams by a mass of water dis- charged through nine-inch nozzles under 450-foot pres- sure the last remnants of the early methods disappeared.

Chapter Iii. General Topography And Geology Of California

The topographical features of central California, as demonstrated by the explorations of the State Geological Survey, are found to be exceedingly simple. Four equi- distant parallel lines can be used in conveying a general idea of the physical geography of the State.

The Three great Belts of California,— A " main axial line," whose course would be N. 31° W., passing through the culminating peaks of the Sierra Nevada for a distance of nearly five hundred miles, can be assumed as the eastern boundary of the gold region. A second parallel, drawn fifty miles west of the " main axial line,*' will skirt the west base of the Sierra Nevada, along the edge of the foot-hills, from Red Bluff to Visalia. A third parallel, run equi-distant from the second, will follow very closely the eastern edge of the Coast Ranges from the neighborhood of Clear Lake to that of Kern Lake, a dis- tance of over three hundred miles. A fourth equi-distant parallel will represent, as nearly as possible, the coast line of the Pacific, the western base of the Coast Ranges. These parallels divide the central portion of the State be- tween Red Bluff (about lat. 40° N.) and Fort Tejon (about lat. 35° N.) into three belts — viz., the Sierra, the Great Valley of California, and the Coast Ranges.

This arrangement of the physical features holds good for a length of four hundred miles in the direction of the " main axial line.** This division of California is the largest and by far the most important, embracing almost

See vol. i., Geological Survey of California," and Whitncy'R Auriferous Gravels of the Sierra Nevada of California," which are the principal authorities for this chapter.

54 Topography And Geology

the whole of the agricultural and the greater part of the mining districts.

These lines divide the State geologically as well as physically. The Great Valley is the belt of recent allu- vial deposits ; the Sierra is the belt of intrusive granite, of strata principally of triassic and Jurassic age, with im- portant pliocene river deposits, of ante-cretaceous eleva- tion, and of metamorphism induced by heat and pressure and resulting in a hard and crystalline condition of the rocks ; the Coast Ranges form the belt of strata chiefly of cretaceous and tertiary age, of post-cretaceous elevation and of chemical metamorphism.

The Sierra is the belt of the precious metal, with some iron and copper ; the Coast Ranges, principally of quick- silver and carbonaceous materials. The Sierra is the region of lofty heights, the Coast Ranges of moderate elevations, and the Great Valley of nearly dead level.

In the Sierra volcanic activity has ceased, but in the Coast Ranges solfataric action is still apparent.

This parallelism does not exist in the northern and southern parts of California. North of lat. 40 N. the Sierra and Coast Ranges approach one another and finally connect, the distinction between them being not yet defi- nitely settled. In the south the Sierra swings to the west and joins, physically at least, with the Coast Ranges, which here, following the coast line, trend to the east. Thus the Great Valley is closed in its upper and lower extremities. The northern and the southern portions of the State have not been thoroughly examined, and the present knowledge of their topography and geology is very limited.

The map accompanying this work shows the mountain ranges where the auriferous gravels exist and also the streams draining the hydraulic mining districts.*

The map was compiled from the latest official surveys by William Hammond Hall, State Engineer of California. For the purposes of this work certain additions have been made by the author.

Of The Coast Range Belt. 55

The Belt Of The Coast Ranges.

Topographical Limits. — Exactly where the Coast Ranges begin and where they end is still an open ques- tion, and to decide this point satisfactorily more geological research is required. For the present general purpose, and until more exact data are furnished, it may be assumed that the belt of the Coast Ranges commences on the north at, or about, the mouth of the Klamath River. Its east- erly boundary will run southeasterly to the head of the Sacramento valley, in the neighborhood of Shasta, and thence continue to Fort Tejon. From this point it passes to the east of the San Gabriel range, through Cajon Pass, to the east of the Temescal range and to the south of the Sierra de Santa Ana, striking the ocean in the vicinity of San Luis Rey, or perhaps including a narrow strip of territory along the shore south to the Mexican boundary.

Mountain System. — In this belt the mountains are not grouped in any one dominant range, but form nume- rous chains, much broken, and often running into one another, and all nearly parallel with the coast lines. These chains are separated by more or less distinct valleys, the system being broken through completely in only one place — namely, where the united waters of the Sacra- mento and San Joaquin rivers, which drain an area of fifty-seven thousand two hundred square miles, escape through Suisun, San Pablo, and San Francisco bays and the Golden Gate.

Compared with the Sierra Nevada, the Coast Ranges attain but inferior elevations. The dominant peaks of the several chains vary in height from thirty-five hun- dred to six thousand feet, few exceeding this limit. In the Sierra, on the other hand, there are numerous points over fourteen thousand feet above sea level, and for a large part of the range the passes have an elevation of more than nine thousand feet.

$6 Topography And Geology

General Topogrraphical Stracture. — In the ex-

treme northwestern part of the State the general struc- ture of the Sierra Nevada prevails — an axial mass of granite associated with hard, crystalline rocks forming a high range. Coming south, and into the northern part of the Coast Range belt (west of Trinity and Kla- math rivers), the structure is modified, the granite disap- pears, the old crystalline rocks are replaced by newer and softer strata, the elevations decrease, and the ranges become more numerous and indistinct, although as far as Clear Lake there is still one dominating range, quite well defined and parallel with the coast line.

South of Clear Lake the ranges are very much inter- mixed, the hills are lower and more rolling, and the val- leys are wider. The average elevation decreases steadily to the vicinity of San Francisco Bay, the point of maxi- mum depression.

Further south, to the bay of Monterey, there are two distinct ranges, that of Mount Diablo on the east and the Santa Cruz mountains on the west, with the southern part of the bay of San Francisco and the important valley of Santa Clara between.

South of the bay of Monterey, as far as San Luis Obispo County, the country becomes more mountainous and confused. The general elevation increases and the valleys become narrow and small. There can be dis- tinguished, however, three equally plain systems : the continuation of the Mount Diablo range, east of the San Benito River; the Gavilan range (connecting with the last at its southern extremity), between the San Benito and Salinas rivers ; and the Palo Escrito hills and Santa Lucia range on the west.

From the northern boundary of the belt to the south of this region the ranges have, in general, a sufficiently well marked northwest and southeast direction, as seen by the courses of the principal streams. Here, however, a change occurs, the coast line, and with it the mountain

Of The Coast Range Belt. $7

chains, making a sudden turn nearly east and west, or almost at a right angle. The Sierra Nevada also bends around towards the west and meets the Coast Ranges, and hence results a confusion of topographical structure and of geological formation. The highest elevation of the belt, that of Mount San Antonio in the San Gabriel range, is here attained.

South of Los Angeles the coast line returns nearly to its former northwest and southeast course, and the ranges appear to come into general conformity with it ; but there is apparently much irregularity in the details, of which, in fact, but little information is extant.

General Geological Structure,— As a general rule the rocks of the belt of the Coast Ranges are altered and unaltered sandstones, shales and slates of cretaceous and tertiary formations, with more or less limestone. The sedimentary beds have been metamorphosed over wide areas, crushed and folded to form the various ranges. In some regions volcanic rocks appear in large quantities. Granite occurs here and there, but almost always in small masses, except where the Sierra Nevada makes its influ- ence felt. It forms an important feature, however, in some of the chains south of Monterey Bay, and forms the axis of the Santa Monica range, which differs in this re- spect from the other Coast Ranges. Other rocks are almost unknown, except where the Coast Ranges and the Sierra come into close contact.

Metamorphism. — The metamorphism of the rocks is principally chemical, and is very prevalent throughout the belt, often to such an extent that it is extremely diffi- cult, if not impossible, to distinguish between rocks of the most opposite nature, such as the eruptive and the sedimentary. Especially noticeable is the enormous ex- tent of change of slates into serpentine, in connection with which broken jaspery rocks, also a product of the alteration of slates, very commonly occur. These combi- nations of serpentines and jaspers are important to the

58 Topography And Geology

miner, as being the carriers of the quicksilver ores so ex- tensively worked.

Cretaceous Formations. — The cretaceous forma- tions are geologically very important, especially from a mining point of view. In the sandstones of the upper part of this formation occur all the workable beds oi coal yet discovered.

Coal and Cinnabar Deposits.— Cinnabar deposits have been found in California in many localities and in rocks of nearly every age —in the Sierra Nevada and in the southern part of the State, in the triassic strata ; in the Coast Ranges, also in the tertiary. But, so far as known, no valuable bodies of this mineral have been met with, except in the cretaceous, in which position it is known, in small quantities at least, in very numerous places, extending in a line with the metamorphic cre- taceous from across the Oregon line in the north to the vicinity of Santa Barbara in the south.

The cretaceous formation, principally slates, jaspers, serpentine, and coarse sandstones, is almost the exclusive one north of Clear Lake ; and south from there to San Francisco, in which region limestone occurs quite fre- quently, it still predominates. South of San Francisco Bay it forms the central and prevailing mass of the Mount Diablo range, extending as far as the north end of Tulare Lake, and gradually yielding to the tertiary. It also constitutes the crest and eastern side of the Santa Cruz range. In both these chains the cretaceous rocks are chiefly slates and sandstones, often highly altered, with limestone in smaller amounts ; and serpentine and jaspers, " which have been traced unmistakably to their origin as cretaceous shales,'* are abundant. South of Tulare Lake the cretaceous formation is local and comparatively unimportant.

Tertiary Strata. — The tertiary strata are principally miocene, of marine origin, and for the most part are not much metamorphosed. They are hardly known north of

Of The Coast Range Belt. 59

Clear Lake, although the great bituminous slate forma- tion has been traced from Cape Mendocino through the country south to Los Angeles.

South of the bay of San Francisco the strata of this slate formation are everywhere turned up at a high angle, while north of the bay they are less disturbed. The ter- tiary, which is so limited north of San Francisco Bay, in- creases in importance going south. It flanks the cre- taceous on both sides of the Mount Diablo range, and gradually limits it. The western and larger portion of the Santa Cruz range (the geology of which is somewhat complicated by the presence of intrusive granite rocks in various places) is said to be miocene. In the Gavilan and Santa Lucia system of ranges the tertiary is continued, and granite and highly metamorphosed rocks occur in considerable quantity; but the region is dry and very rough, and has been but little explored.

Aftphaltum Deposits. — The different ranges in Santa Barbara and Ventura counties are made up chiefly of miocene rocks, consisting principally of a coarse-grained sandstone below, and over this a fine-grained slate or shale, often highly bituminous and generally very much contorted and tilted nearly vertical. In. Santa Barbara, Ventura, and Los Angeles counties, where the tertiary bituminous slate predominates, the principal deposits of superficial asphaltum have been found, and here attempts have been made to strike flowing petroleum wells.

As one approaches the Sierra Nevada to the east of this region, and also in going south, granite becomes more frequent and the sedimentary rocks get harder and more crystalline. There is a granitic belt forming a con- tinuation of the San Gabriel range, and connecting at Tejon Pass with the metamorphic and gnitic masses of the Sierra, the crystalline rocks being apparently con- tinuous, but the disturbance of the tertiary and cretaceous formations not being visible cast of Tejon Pass. The granite forming the divide between the branches of the

6o TOPOGRAPHY AND GEOLOGY

Santa Clara River and the Mojave Desert is overlaid on the edge next the plain with stratified beds of recent vol- canic material.

Tin Ore. — South of Los Angeles the ranges are of mixed character, and are very often considered as not belonging to the Coast Ranges proper. The Sierra de Santa Ana is composed on the south of granite, trap- pean and metamorphic rocks, while on the north coarse miocene sandstone and conglomerates prevail. The Te- mescal range consists principally of granite, porphyry, and metamorphic sandstone, partly cretaceous and partly tertiary. Here is the only known locality on the coast north of Mexico where tin ore has been found.

Still further south toward the Mexican boundary there is, along the ocean shore, a narrow strip of unaltered cre- taceous and tertiary rocks.

Pliocene Gravels. — Pliocene gravels occur in vari- ous places in the Coast Ranges, sometimes in large de- posits. These are in many cases the work of disinte- grating adjacent formations. Gold has been found in some places, but seldom in paying quantities.

North of Clear Lake, at the bottom of the caftons which have been cut out chiefly by nmning water, are sometimes small deposits of gravel of pliocene age. These, especially at the north, carry gold. Between Clear Lake and San Francisco the only large gravel bed is the extensive one east of, and not far from, Clear Lake. This bed is covered in part by lava.

There are several localities in which deposits of gravel, probably pliocene, occur in the miocene strata of the Mount Diablo range, as south of the Livermore val- ley, but these contain no gold so far as known. Similar deposits are also found on the eastern edge of the Santa Cruz range, as on the east slope of the Mount Bache ridge, where considerable ground has been washed for gold, biit without profit. Between the Gavilan and Mount Diablo ranges, south of Tres Pinos, there is an

Of The Coast Range Belt. 6 1

immense mass of pliocene gravel, apparently non-auri- ferous, made up of pebbles of gnite, red and green jas- pers, silicious slates, and other metamorphic material. In the Santa Lucia range, near the Mission San Antonio, placers have been worked to some extent, and gold has been found in small quantities in several places.

The miocene strata of the ranges in Santa Barbara and Ventura counties are covered unconformably in places by nearly horizontal and slightly disturbed plio- cene beds. In various places south of the junction, near Fort Tejon, of the Sierra Nevada and Coast Ranges, plio- cene gravels occur over small areas. At San Francisco cafion these gravels have been washed and more or less gold obtained at various times since 1841 according to some authorities, and since 1838 according to Father Venegas.

Along the San Gabriel range gold-washing has been carried on intermittently with more or less profit. At the base of the Sierra de Santa Ana are immense accu- mulations of gravel made up of the wash of disintegrated tertiary strata.

Gold, Silver, and Copper Veins.— Veins of gold, silver, and copper have been reported at different locali- ties along the Coast Ranges.

Eruptive Rocks.— A belt of eruptive rocks, of which Mount St. Helena is the culminating point, extends from near Napa to Clear Lake down to Suisun Bay, and large areas in this region are covered by lava, obsidian, pumice, and volcanic ashes. Especially in the vicinity of Clear Lake modern volcanic formations abound, and hot springs, sulphur beds, and other evidences of modern igneous action are common; but to the north of Clear Lake no volcanic phenomena of the kind are known, and south of San Francisco volcanic rocks are not found in any large quantities. Hot and sul- phur springs are, however, quite common in the Coast Ranges.

62 Topography And Geology

The Great Valley Of California.

General Topography.— The valleys of the Sacra- mento and the San Joaquin rivers form in the centre of California a large plain, nearly elliptical in shape, extend- ing from near Shasta, in lat. 40° 40' N., to Fort Tejon, in lat. 34® 50' N., an extreme length of four hundred and fifty miles, with an average width of forty miles, and an area of eighteen thousand square miles.

This plain is comparatively level. The Sacramento River, between Shasta and its mouth, has an average fall of 2.8 feet per mile. The San Joaquin River, from Kern Lake to its outlet, has an average inclination of i.i feet per mile. The valley of the Sacramento is narrower than that of the San Joaquin. The southern portion of the latter is very level and contains several shallow lakes of considerable area. The evaporation here about equals the water supply.

Drainage. — By far the larger part of the water com- ing into the Great Valley is derived from the Sierra Ne- vada. There is hardly a stream which furnishes water throughout the year on the east slope of the Coast Ranges, certainly not one in the San Joaquin division. The fact that many rivers, passing chiefly through the mining regions, flow down the west slope of the Sierra and empty into the Sacramento or San Joaquin, makes the whole drainage system worthy of attention.

Rainfall. — The rainfall of the Great Valley is com- paratively small, especially in the southern parts. On the east slope of the Coast Ranges the amount of water de- rived from rain is small. On the west slope of the Sierra there is considerable precipitation, chiefly in win- ter, and in great part in the shape of snow. In the spring and early summer the flow of water down the last men- tioned slope is greater than at other seasons, so much so that every year freshets occur. Heavy storms often cause destructive floods here, and if the theories of many

Of The Sierra Nevada. 63

who have written on the subject of forests are correct, these floods will increase in magnitude with the destruc- tion of timber in the Sierra.

The Belt Of The Sierra Nevada.

Topogrraphical Structure,— The Sierra Nevada is a well-defined range of mountains situated on the edge of a high plateau, its eastern base being about four thou- sand feet high, while its western side slopes nearly to the sea-level. Its eastern flank is comparatively short and steep ; its western, long and with a gradual descent, aver- aging in the central part of the State about one hundred feet per mile. This west side is broken by steep cafions in which the present rivers flow, running at about right angles with the axis of the ridge, so that an elevation of three thousand to four thousand feet above the sea-level the divide between any two streams is from several hun- dred to two thousand feet, or more, above the bottoms of the cafions on either side.

In the northern part of the State the range is outlined indistinctly, consisting of broken ridges with several pro- minent peaks. The general elevation may be assumed to be seven thousand or eight thousand feet. Mount Shasta, the highest point of this section, rises to a height of four- teen thousand four hundred and forty feet, dominating over all the others. South of this, from Lassen's Peak (lat. 40° 40' N.) to near Tejon Pass (lat. 35 N.), the Sierra Nevada forms one clearly defined crest, gradually in- creasing in height toward the south. Along the head- waters of the Feather River, in Plumas and Sierra coun- ties, the elevation of the prominent peaks is about nine thousand feet, and of the passes from five thousand to six thousand feet. Lassen's Peak rises ten thousand five hun- dred feet above the sea-level. The western slope here has a total width of some eighty-five miles.

Around the head-waters of the American River, in Nevada, Placer, and El Dorado counties, the main crest is

64 Topography And Geology

a little over nine thousand feet high, and the passes seven thousand to eight thousand feet ; Donner Pass, through which the Central Pacific Railroad is built, being seven thousand feet high. The range here divides into two crests between which lies Lake Tahoe, a body of water twenty miles long, eight to twelve miles wide, and a lit- tle over six thousand feet above sea-level.

At the head-waters of the Merced and Tuolumne rivers, in Tuolumne and Mariposa counties, the main peaks are twelve thousand to thirteen thousand feet high, and the passes nine thousand to ten thousand feet. The width of the western slope is fully eighty miles.

The highest Sierra is between lat. S/"" 31' N. and lat. 36 N., in the region of the head-waters of the Kern, King's, and San Joaquin rivers. Here the main crest is twelve thousand to thirteen thousand feet high, with numerous points exceeding fourteen thousand feet. Mount Whitney being the culminating peak. The west slope is some fifty miles wide, with an average descent of two hundred and fifty feet to the mile.

Still further south the range turns to the west, and from this point is less marked in its character. In the southern part of the State is a mass of high, broken ranges (the San Bernardino range being the most ex- tensive) allied in their general structure and formation to the main Sierra Nevada, but as yet insufficiently ex- plored.

General Geological Structure.— The Sierra Ne- vada is made up of :

(i) a central intrusive core of granite, flanked by

(2) metamorphic slates of triassic and Jurassic age (the so-called auriferous slate formation), over which lies

(3) a covering of cretaceous, tertiary, and post-tertiary deposits, which are either

{a) the river deposits which form the material which is washed, either by hydraulic or drift process, to extract the gold contained therein ; or

Of The Sierra Nevada. 65

{b) sedimentary volcanic layers ; or

{c) lava ; or finally, in some places,

{d) marine formations.

Granite. — The granite occurs in the .extreme north- western part of the State, disappearing in the northeast- ern under the extensive lava beds, reappearing in Butte and Plumas counties, and continuing to increase in amount of exposure toward the south, until in Fresno and Tulare counties it forms territorially by far the greater part of the belt, extending from the crest almost down to the plain.

Auriferous Slate Formation.— The auriferous slate formation, consisting chiefly of metamorphic, crys- talline; argillaceous, chloritic and talcose slates, appears with, but subordinate to, the granite in the northwest. It appears again in Plumas and Butte counties, increasing in importance as the overlying lava decreases. North of the American River it occupies nearly the whole width of the western slope of the Sierra, with occasional areas of granite enclosed in it. Going south, it gradually con- tracts in width, being of but little importance south of Mariposa County. In the extreme south, at the junction of the Sierra and the Coast Ranges, it reappears and con- tinues in San Bernardino and San Diego counties in con- nection with the granite.

The strata of this formation are elevated very con- siderably, often in a nearly vertical position. Speaking in very general terms, it may be said that the strike of the slates is usually parallel with the axis of the range and the dip in the southern portion of the belt is generally to the east.

Gold Quartz Veins.— In this formation occur al- most exclusively the veins of quartz which carry gold in amounts which pay for working. While such veins occur also in the granite, and likewise, as has been mentioned, in some of the Coast Range formations, the paying gold quartz is rarely found outside of the auriferous slate formation. Some of these veins are of very great size,

66 Topography And Geology

notably the " great quartz vein,*' which has been traced from near the centre of Amador County through Cala- veras and Tuolumne into Mariposa to the Mariposa Es- tate, a distance of eighty miles. The vein attains a width, in places, of several hundred feet.

Carboniferous Lfimestones. — There are certain limestones in Shasta and Butte counties which are car- boniferous, the oldest formation known in the State, and which are possibly the same as those found here and there throughout the gold-mining region.

Marine Sedimentary Deposits. — The marine sedi- mentary deposits of cretaceous and tertiary age occur in the foothills all along the eastern margin of the Great Valley, lying unconformably on the upturned edges of the auriferous slates. Their greatest development is in Kern County, between Kern and White rivers. The rock is lor the most part a soft sandstone, made up chiefly of granite debris.

Lava* — The chief lava country is in Plumas and Butte and the region north of these counties, and east of Trinity and Klamath rivers. Here is a series of volcanic cones, of which Lassen's Peak and Mount Shasta are the most pro- minent, from which flowed, in the later tertiary or still more recent times, the streams of lava which now cover many thousands of square miles of northern California and southern Oregon. The limitation of the auriferous belt at the north, in Plumas and Butte counties, is due not to the thinning out of the gold-bearing formation, but to its being covered by this volcanic mass.

Along the crest of the Sierra, to the south, are nume- rous volcanic vents and here and there are areas of lava, but these are comparatively small.*

Sedimentary Volcanic Layers. — Very frequent, and associated with the gravel deposits, are the sedimen- tary volcanic layers, consisting of fragments of lava which

As to the Tuolumne Table Mountain see J. Ross Browne, Mineral Resources of the U.S.." 1867. page as.

Of The Sierra Nevada. 67

have been carried to a distance by water and deposited as breccia or conglomerate of volcanic ashes or lapilli. These layers stratified, often in alternation with gravel or clay, generally cover the gravel deposits.

Gravel Deposits. — The gravel deposits occur in every variety of texture, from very fine pipe clay, through sands and gravels, to rolled pebbles and boul- ders sometimes weighing tons. It is now generally ac- cepted that they have been laid down by the action of a system of tertiary rivers, which had the same general course (nearly) as the present streams on the west slope of the Sierra, but whose channels were wider and slopes greater. The waters of these rivers, eroding the auri- ferous slates with the included quartz veins, concentrated the precious metals in deposits often three hundred and fifty to four hundred feet wide at the bottom and some- times several thousand feet wide on top. Their depth now varies from a few inches to six or seven hundred feet. Volcanic eruptions have in places covered these deposits with lava and tufa hundreds of feet deep. Denudation and erosion ensued and the products of volcanic activ- ity have sometimes been covered in turn with gold-bear- ing detritus. Quantities of fossil wood and numerous re- mains of land and water animals have been found in the deposits and are being constantly unearthed as the mines are being worked.*

The deep cafions of the rivers of the extreme northern counties, especially the Klamath and its branches, contain

In reference to the occurrence of gold the following note, taken from the Rngitutring and Mining Journml February 10, i877 relative to the discovery of pay gold in the New South Wales coal measures, will be found interesting. Mr. C. S. Wilkinson, F.R.S., writes from the Geological Survey Office, Geelong, under date of November* 25, to the Mining De- partment, as follows :

During my examination of the Tallawang Gold Field Reserve I observed the important fact that the gold found in tertiary alluvial deposits at the old Tallawang and Clough's Gully diggings has been chiefly derived from conglomerates in the coal measures. These conglo- merates are associated with beds of sandstone and shales containing the fossil plant of our coal measures, the//MM>//r/r. . . . This is the first time that gold has been noticed to occur in payable quantity in the coal measures in the colony, and it is not unworthy of remark that we hre posKss one of the most ancient alluvial depouu in the world."

68 Topography And Geology

large amounts of gravel which have been washed quite extensively. These gravels are, however, thought to be ordinary river deposits on a large scale. In the southern part of the State, in Santa Barbara and San Diego coun- ties, gold-washing has been carried on to some extent, but under unfavorable conditions and apparently without much profit.

Deposits at La Grange. — The deposits at La Grange, Stanislaus County, in a distance of one and a half miles in a northerly and southerly direction, cross four distinct and widely varying formations (see annexed topographical and geological section), which, enumerated in accordance with their relative ages, are : argillaceous slates, occurring north of the Tuolumne River, probably Jurassic ; diorite ; a thin stratum of basaltic tufa ; and post- pliocene auriferous deposits of sand and gravel.

The slates have a general strike northwesterly and southeasterly, parallel to the general trend of the Sierra Nevada Mountains, and dip at an angle of about sixty de- grees. The diorite is occasionally porphyritic, changing into aphanite and serpentine in places which, so far as ob- served, are not on the direct line of the section. It some- times contains quartz, and must be classed as syenitic. Where overlaid by basaltic tufa or gravel it is very much decomposed, presenting the appearance of clay shale, showing thick-bedded stratification, a water- worn and un- dulating surface, with numerous pot-holes similar to a river bed.

The basaltic tufa, from two to six feet thick, occurs in more or less isolated patches, having been washed away in places and cut up by streams previous to or during the deposition of the gravel. It is generally of a light green- ish or yellowish color, occasionally pink or of a rusty iron tinge, and frequently contains angular quartz pebbles and rounded masses of flint-like rock.

The auriferous deposits of sand and gravel rest upon the tufa, and are not capped by any volcanic flow. Bones

Of The Sierra Nevada. 69

and teeth of the elephant have been found imbedded in them. The gravel is composed of such rocks only as are found to the eastward in the foothills and the mountains of the Sierra Nevada, and consequently must have come from that general direction.

A section of the gravel occurring in the New Kelly claim shows the deposit to consist of :

I. Top soil (red sand) 1.7 feet.

II. Coarse red gravel with sand (the gravel is chiefly

granite) 6.1 "

III. Red cement hard-pan 6.0

IV. White sandy clay 0.8 "

v. Red cement hard-pan 3.3

VI. Sand and pebbles 6.5 "

VII. Loose yellowish sand 7.4

VIII. Dark-colored gravel of granite, slate, porphyrJ greenstone, aphanite, serpentine, quartzite, diorite, etc 13.2 "

Total 45.0 "

Quartz gravel of large size is of rare occurrence. Boulders of diorite, several tons in weight, are common in some of the deeper holes of the bed-rock. The greater part of the gold is confined to the lower stratum of gravel, next to the bed-rock, and is associated with magnetic iron and platinum.

Chapter Iv.

THE DISTRIBUTION OF GOLD IN DEPOSITS AND THE VALUE OF DIFFERENT STRATA.

No absolutely satisfactory explanation has yet been given of the distribution of gold in deposits.

The opinion is held by some that the precious metal is uniformly disseminated throughout the beds. But this is the case only in very exceptional instances, and the un- equal distribution of the gold f is so general as to have given rise in California to the expression "pay dirt,** which means the stratum or strata containing gold in amounts which render work profitable.

Top Gravel sometimes pays. — In a few instances the gold occurs in comparatively large amounts in thin streaks of cemented gravel scattered here and there in the alluvions, and in some shallow banks J it is quite generally disseminated. Even in high banks the upper portion or " top gravel,'* when consisting of fine light quartz-wash with no boulders or pipe-clay, and where the cost of hydraulicking is very small (owing to the facilities of a heavy grade, sufficient dump, and cheap water), has been washed at a profit, though carrying an insignificant amount of gold per cubic yard. For this reason the miner always tests the whole of the deposit.

♦ Sec The Auriferous (Jravels of the Sierra Nevada of California/* p. 516. By J. D. A'hitney.

t On the subject of the relative position of gold in deposits see Report of Mr. Stutchbury, Government Geologist of New South Wales ; Quarterly Jour. Gtol, Sac. 1858, p. 583, M. A. Selwin ; " Gold-Fields and Mineral Districts of Victoria," pp. 81, 8a, 87, 131, 173, R. Brough Smythe ; Cotu's " Lehre v. d. ErxlagersUCtten," vol. i. p. 101, and vol. ii. p. 556 ; Murchison's " Russia and the Ural Mts.," vol. i. pp. 482-487, and Siluria," p. 456 ; Whitney's " Auri- ferous Gravels of the Sierra Nevada.** p. 361 ; J. Grimm's " IagerstStten d. Nutzbaren Mine- ralien," p. a6 ; Hartt's Geol. and Phys. Geog. of Brazil," pp. 50, 51, 159, j6o : Mawe's Tra- vels, pp. 923-297 ; Munroe's Mineral Wealth of Japan,*' Trans. Amer. Inst, of Mining Engi- neers, vol. V. p. 236 ; Gold Deposits of Jaragua," Ann. d. MintSy 1817, vol. ii. p. aoa.

X See Gold-Fields and Mineral Districts of Victoria," p. 84.

Distribution Of Gold In Gravel. 7 1

The top gravel of the channel which passes through Columbia Hill, Nevada County, has in several instances been successfully washed. This is especially remarkable on account of the great depth of this deposit, which, from the explorations on Badger Hill and Grizzly Hill, is in- ferred to be from six hundred to six hundred and twenty feet deep.

Gold in the Grass-Roots.— Not unfrequently a fine lamina gold is found in the grass-roots. This last men- tioned circumstance is in no way localized, the same fact having been noted in other countries. Mawe called atten- tion to the existence of gold in the grass-roots on Mount San Antonio,* in Brazil ; and Walsh states that gold was first discovered in the deposits between San Jos6 and San Joao, Brazil, by Paulistas, who, pulling tufts of grass, " found numerous particles of gold entangled in the roots." t

Pay Gravel sometimes high above Bed-Roek. —At the Polar Star Mine, Indiana Hill, Placer County, the best pay was found from six to eighty feet above bed- rock. At diggings near Forest Hill, Placer County, the gravel twenty to sixty feet above the bed-rock has yielded profits. At Bath a stratum one hundred feet above bed- rock was drifted profitably and the top dirt hydraulicked subsequently.

Pay Gravel generally near Bed-Bock. — But ex- perience has proved that, as an almost universal rule, the top gravel of deep alluvions is not rich enough to warrant large investments of capital. Also that the " pay " is ob- tained, not from the washings of the entire bank, but chiefly from that stratum or those strata which are in most cases within eight or ten feet of the bed-rock. Where this is of slate upturned on its edges the gold frequently permeates it one or two feet.J

♦ Mawe's TravcU, p. 264. + Walsh's " Notices of Bnuil," 1838-09, vol. ii. p. tti.

X See Murchison's Siluria," p. 456, and " Ruxsia and the Ural Mountains/* vol. i. p. 487 ; also Gold-Fieldsand Mineral Districts of Victoria,*' pp. 86, 106.

Distribution Of Gold In Gravel.

Taolumne River Claims. — The gold alluvions found near and along the banks of the Tuolumne River, Stanislaus County, present some striking examples of the distribution of the precious metal. The pay dirt in the Chesnau claim is confined to within six feet of the bed- rock. In the Sicard claim, six hundred feet south of the last and across a ravine, with banks twenty to forty feet high, the gold is disseminated more generally so long as there are no sand strata ; but whenever the latter appear the pay is confined to near the bed-rock.

In the Patricksville Light claim the pay stratum is six or seven feet thick and adjoins the bed-rock. The gold is concentrated in this layer so long as there are sand strata in the bank, but with their disappearance it becomes more diffused throughout the detritus.

At the French Hill claim the pay was limited almost exclusively to the gravel near the bed-rock.

Nevada County. — The bulk of the pay dirt in the cement gravel in Nevada County is within thirty feet of the bottom. In drift claims the workings are nearly al- ways confined to within a few feet of the bed of the channel.

Sand generally poorer than Gravel. — In the gold-bearing drift of the Sierra Nevada layers consisting exclusively of wash-sand are generally found to contain very little if any of the precious metal.

Rich Pay in Undulations and Depressions.— At French Hill, Stanislaus County, where the bed-rock was undulating, and in depressions found around a little hill formed by a sudden rise in the bed-rock, the gravel paid better than in any other portion of the claim.

The gold-fields south of Miask,* in the Ural Mountains, present a similar case, all the undulating ground and de- pressions around conical hills being the most productive of gold.

At the Patricksville Light claim a large hole in the

" Russia and the Ural Mountains,*' vol. i. p. 488.

Values Of Different Strata. 73

bed-rock, twenty-five feet deep, was bottomed. The hole was filled with gravel, but no pay was obtained. The pay stratum was found to be on a level with, and a continua- tion of, the pay stratum of the rest of the claim. On the other hand, at the Chesnau and French Hill claims when- ever these hollows are found a large yield of gold is in- variably obtained.

The experience of miners in the gold-fields of Victoria has led to the conclusion that " in large auriferous rivers gold is always found on the bars or points, and not in the deep pools or bends." In substantiation of this are cited Reid's Creek, Woolshed, Twist's Fall, Yackandanah near Osborne's Flat, and Rowdy Flat ; at each of these places large holes were cleaned out and only a few colors obtained, while shallow flats immediately below them were very rich.*

In gulch-mining it sometimes happens that from the position of the bed-rock the detrital accumulations assume the form of reclining cones, the apex reposing upon the top of the hill. Where such is the case the bulk of the gold is concentrated in the lower end of the deposit. These gulches are frequently found to be exceedingly rich.

These facts are cited merely as an explanatory outline of the subject, and to show why a system of sluicing should be adopted which bottoms the entire deposit.

Examples Of The Comparative Values Of The Dif- Ferent Gravel Strata.

North Bloomfleld. — To ascertain the comparative value of the gravel strata at Malakofif, Nevada County, on the ground of the North Bloomfield Mining Company, a series of tests was made of the dirt extracted from a shaft sunk, two hundred and seven feet deep, in the channel. The first one hundred and twenty feet from the surface

Gold- Fields and Mineral Districts of Victoria," p. 134.

74 Values Of Different Strata.

contained a large number of very fine colors to the pan, but of inconsiderable weight. The gravel from the re- maining eighty-seven feet, sunk to the bed-rock, contained coarser and heavier gold, the last eight feet averaging from 5 to 20 cents per pan. Drifts opened from the bot- tom of this shaft were systematically sampled and com- pared with equal quantities taken from the layers of the upper bank. The several samples aggregated two and a half tons, all of which were panned out carefully in two hundred and forty tests ; and the results obtained showed that the blue or lower gravel stratum contained $1 50 per ton, while the white or upper gravel gave a large number of fine colors, but of insignificant weight.

From 1870 to 1874 the North Bloomfield Mining Com- pany washed three and one-quarter million cubic yards of top gravel, which yielded only 2.9 cents per cubic yard and a gross profit of $2,232 84. In 1877 a rough estimate was made of the comparative yield of the upper and lower gravel washed during the year. The top gravel was assumed to be from a few feet to over two hundred feet deep, and the bottom gravel sixty-five feet deep.

The results obtained were that 1,591,730 cubic yards of top gravel yielded 3.8 cents per cubic yard, and 702,- 200 cubic yards of bottom gravel returned 32.9 cents per cubic yard.

Patricksville Light Claim. — To investigate more thoroughly the question a test of top and bottom gravel was made at the Light claim, Patricksville : 58,340 cubic yards of top gravel yielded $1,200, or 2 cents per cubic yard. The bottom gravel (four feet deep) was then washed, when it was discovered that two-thirds of this gravel had been drifted extensively ; but notwithstand- ing this fact 4,966 cubic yards yielded $2,775 07, or 55 cents per cubic yard.

La Grange Liglit Claim. — A trial of top dirt was also made at the Light claim. La Grange: 41,038 cubic yards of top dirt yielded $1,500, or 3.7 cents per cubic

Values Of Different Strata. 75

yard. The ground, in both of the last mentioned in- stances, was surveyed and the returns per cubic yard are as accurate as it is practicable to obtain.

Polar Star Mine. — In the appendix to the " Aurife- rous Gravels of the Sierra Nevada of California/* Pro- fessor W. H. Pettee estimates the value of the top gravel at the Polar Star Mine to be about 1 1 cents per cubic yard, and at Quaker Hill the yield of the top gravel. is supposed to approximate 6 cents per cubic yard. The yield of the bottom gravel, however, is not given, and the estimates of the upper gravel are approximates based on the statements of others, and not the results of accurate detailed surveys.

Chapter V.

Amount Of Workable Gravel Remaining In California.

The quantity of auriferous gravel remaining on the flanks of the Sierra Nevada is very great, but necessarily the amount available foi* hydraulic mining is limited.

Minimum Fay Yield. — The minimum yield per cubic yard of material which can be mined protita- bl}', must be considered in determining the extent of workable deposits. This cannot be stated in advance without a knowledge, in any given case, of the other factors : as area of ground, character and depth of deposit, facilities for working and dump, supply and cost of water, price of labor and amount of capital invested. In certain localities, even tinder very disadvantageous circumstan- ces, it has paid to work gravel yielding only four cents per cubic yard ; and Mr. Skidmore states that, within his personal knowledge, a claim near Iowa Hill, Placer Coun- ty, in 1879 Pid fair profit" when the product was only three cents per cubic yard.

With an abundance of cheap water, four per cent, grades, good dump, banks of light gravel one hundred and fifty feet in height and over, a large area of ground, labor at one dollar per diem, and good management, the total running expenses ought not to exceed three cents per cubic yard at the present time, and with present methods. Therefore under these conditions gravel yielding more than three cents per yard ought to pay a greater or less rate of interest on the capital invested in the purchase of the claim and water rights, the building of necessary ditches, flumes, pipes, etc., and in the other appliances requisite for commencing active operations.

Amount Of Workable Gravel Ix California. Jj

The reports of the State Engineer of California (1880) and of Lieut.-Col. Mendell, U. S. A. (1882), give the fol- lowing data of the estimated amounts of workable gold deposits remaining along the rivers of the principal hy- draulic region on the west flank of the Sierra Nevada in CaUfornia :

Cub. yds. of Gravel.

The Upper and Lower Feather, large amounts Unestimated

The Yuba and its tributaries, about 700,000,000

The American " 75,000,000

The Cosumnes, principally at Hill Top, from ii,ooo,-

000 to 12,000,000, say 11.500,000

The Mokelumne, enormous amounts, but not favor- ably situated Unestimated.

The Calaveras, upper portion Unestimated.

" lower portion, principally at Jenny

Lind 22.560.000

The Stanislaus Unestimated.

The Tuolumne, large amounts Unestimated.

" The quantity of auriferous gravel now remaining on the flanks of the Sierra Nevada is practically unlimited. Only a comparatively small portion of the whole can be regarded as workable under existing conditions."

Since Mr. Hague's report upon Eureka Lake proper- ty (1876), wherein it is stated that the quantity to be mined between the Yubas was 700,000,000 cubic yards (roughly estimated), explorations have proven that this estimate is too large. It is true that there was that quan- tity of gravel, and perhaps more, in that locality. But since then a quantity, possibly exceeding 100,000,000 yards, has been mined out, and the result of the work has prov- en that a portion of this gravel channel can never be mined profitably, for the reasons, ist, that it is capped with lava and cannot be hydraulicked, and it will not pay to drift; and, 2d, another portion is so situated that it is impossible to drain it, or it is too far from the streams to dispose of the debris. It is now estimated that not more than 400,000,000 cubic yards of gravel remain here available for washing.

Report on Mining Debris in Gal. Rivers, by Licut.-Col. G. H. Mendell, U.S.A., p. 35.

Chapter Vi. The Different Methods Of Mining Gold-Placers.

The gold alluvions occur in many different forms : in river channels, in basins and on flats, as surface de- posits of sand and gravel, or as accumulations of detritus (consisting of clay, sand, gravel, pebbles, and boulders of all sizes) covered with varying thicknesses of lava and other volcanic products.

Miners' Classification of Deposits. — Miners clas- sify the deposits in various ways, according to their mode . of occurrence and topographical position, and according to the mining systems employed in working them. The term " shallow placers " is applied to deposits whose depth varies from a few inches to several feet, to dis- tinguish them from "deep placers,'* which often cover large areas and have a depth varying from one hundred to several hundred feet.

" Hill Claims,** or deposits of gravel on hills ; " Bench Claims,*' or placers occurring in bench form on declivi- ties and above the level of existing rivers ; " Gulch Dig- gings,** found in gulches and ravines ; " Flat Deposits," on small plains or flats ; " Bar Claims,*' or bars of sand and gravel on the sides of streams, generally above the water- level ; and " Beach Sands,** or the auriferous sands of the sea-shore, are terms in common use, as well as the names " sluice," drift,*' and " hydraulic " diggings.

Classification of Alining Operations. — The min- ing methods in common use may be divided into two general classes — viz., Surface-Mining and Deep-Mining.

Different Methods Of Mining. 79

Surface-Mining.

This term may be applied to the operations on the shal- low placers from which in early days large returns have been obtained, but which from their nature are of a tran- sient character, and in California are no longer in use to any great extent.

Under this head will be treated the methods of Dry- Washing, Beach-Mining, River or Bar Mining, Ground- Sluicing, and Booming.

Dry- Washing. — Dry-washing was carried on in the early days, principally by Mexicans, in those localities where water could not be obtained. The Mexican meth- od consisted in pulverizing selected rich dirt, thoroughly drying it, and then working it in a batea. The earthy portions, by a circular motion given to the disk, were separated from the gold, which remained behind. The gold was also extracted by winnowing. Of late years various machines have been invented and used from time to time, but necessarily their application is limited.

Beach-Mining. — In various places along the Pacific coast, principally between Cape Mendocino in California and the Umpqua River in Oregon, the beach sands have been found to contain gold and have been worked to a limited extent. The first discovery, which for a time caused great excitement, was made in 1850 at Gold Bluff, south of the mouth of the Klamath River.

The gold occurs in a finely divided state, in layers (sometimes one or two feet deep) of magnetic iron sand, which by the concentrating action of the waves and tide is separated from the lighter quartz sand. By the wash of the water the auriferous layers are sometimes exposed and sometimes covered by the non-auriferous material.

With the gold platinum is found. The fragments of the platinum are more compact and less flattened than the gold particles, which are of leaf-like form and of nearly the same diameter as the magnetic-iron grains, from which

8o DIFFERENT METHODS OF MINING.

they are separated only with difficulty by the present pro- cess of washing.

S. B. Christy found that the gold amalgamates easily, but that the finer particles, when once allowed to dry, seem to become covered with a film of air and to float readily on subsequent immersion in water.

Prof. J. D. Dana considers that these deposits date from the close of the Glacial, and partly from the latter half of the Champlain period.

As the tides continually alter the position of the ex- posed auriferous layers, it is necessary to prospect every day for the richest spots, which are generally covered at high water. At low tide the miners proceed to the locali- ties selected, scrape up the thin gold-bearing strata, and transport the material to the washing place. The wash- ing is generally done in sluices, to which are attached various gold-saving contrivances.

It is claimed that much of the sand assays from $io to $30 per ton, and that very large amounts assay from $5 to $10, only a part of which, however, is saved. Skidmore states that the variable character of the sands prevents beach-mining enterprises from being carried on success- fully for any length of time.

Bar and River Mining. — In early days river-min- ing was extensively carried on. The discovery of rich bars caused many excitements. It led to the rapid ex- ploration and settlement of large areas of country, and was generally the first step towards opening up the gold- mining regions.

The portions of the bars above water-level being soon exhausted, the miners' attention was naturally led to the ex- ploration of the parts under water. Streams were dammed and turned into new channels, often at enormous costs and risks. The beds of rivers for considerable distances were laid bare while the miner worked his claim. This class of mining, apart from the danger arising from floods and breaking of dams, had in it a factor of uncertainty —

Different Methods Of Mining. 8 1

namely, the value of the claim, which could only be ascer- tained after all the principal expenses had been incurred. The losses in many instances were very large, but in other cases the gains obtained in a short time were so enormous as to throw around this class of work a fascination which induced many to engage in it.

To obviate the necessity of turning the rivers out of their channels dredging machines have been built and used ; and the plan of sinking shafts on the banks and tun- nelling (drifting) under the surface of the bed has been sug- gested. Projects for working the river channels (always supposed to contain enormous stores of hidden wealth) are still proposed from time to time, but actual operations are not common.

Ground-Sluicing. — Ground-sluicing consists in treating the gold-bearing gravel, which is excavated by pick and shovel, by washing it in trenches cut in the bed-rock. It is similar to hydraulic mining, except that the water is not used under pressure and often no wooden sluices are used below the trenches, the rough natural rock serving for riffles. The lighter material is removed by means of the water, while the heavier dirt remaining behind is collected and worked in rockers. This process of gold- washing was carried on by the Romans in the early part of the Christian era.

Booming. — Booming is simply ground-sluicing on a large scale, the only difference being that instead of wash- ing the gravel by means of a continuous stream of water, the contents of the entire reservoir are discharged at once and all the material which has been collected below it is swept into the sluices. The rush of the water carries off the boulders and dirt, leaving behind the heavy particles of gold and magnetic iron sands, which are collected on bed-rock floors. Booming has been extensively practised in California, Idaho, Montana, and Colorado. The re- quirements for this kind of gold-mining are a iiafficiently large reservoir conveniently situated above the gravel de-

82 Different Methods Of Mining.

posit, and a dam for storing the water, so arranged that flood-gates can quickly discharge the entire contents of the reservoir without damage to the dam.

Pliny, in his "Natural History/' speaking of gold- washing, says : When they have reached the head of the fall, at the very brow of the mountain, reservoirs are hollowed out a couple of hundred feet in length and breadth, some ten feet in depth. In these reservoirs there are generally five sluices left, about three feet square, so that the moment the reservoir is filled the flood-gates are struck away, and the torrent bursts forth with such a degree of violence as to roll outward any fragments of rock which may obstruct its passage. When they have reached the level ground, too, there is still another labor that awaits them : trenches, known as agogae,' have to be dug for the passage of the water, and these, at regu- lar intervals, have a layer of silex placed at the bottom. This silex is a plant like the rosemary in appearance, rough and prickly, and well adapted for arresting any pieces of gold that may be carried along. The sides, too, are closed in with planks, and are supported by arches when carried over steep and precipitous spots. The earth, car- ried onwards by the stream, arrives at the sea at last, and thus is the shattered mountain washed away — causes which have greatly tended to extend the shores of Spain by these encroachments on the deep."

Deep- Mining.

The two principal methods of Deep-Mining are Drift- ing and Hydraulicking.

Drifting. —Gold is often mined in deep deposits by means of tunnels and drifts. This is styled drift-mining, which, as a rule, is resorted to only in those districts where the deposits are covered by an overflow from vol- canic sources, though in many instances the bottom stra- tum (sometimes intermediate strata) has been drifted out of banks not capped with lava.

DIFFERENT METHODS OF MtNING. 83

Drifting presupposes the concentration of the precious metal in a well defined stratum or channel. This method has been extensively employed in many parts of Califor- nia, particularly in Placer, Sierra, and Plumas counties.

Where a pay channel has been found, or is surmised to exist, a tunnel is driven to develop it. This tunnel must be run in such a manner as to drain all parts of the mine, and its location is therefore a matter of the greatest importance. Before commencing such a work, which may require years for its completion and cost large sums of money, every precaution should be taken to ascer- tain the exact position of the channel. Want of know- ledge on this point has caused disastrous failures in but too many cases.

As the channel can often be found only by means of tunnels, the risk of undertaking drift-mining is apparent. In those fortunate instances in which the channel is dis- closed on the surface and rises as it enters the hill, the tunnel is run along its bed, partially in the bed-rock. Otherwise the tunnel is driven below the channel or through the rim-rock, being located with such a grade that the deepest part of the workings will be above it.

In some claims shafts have been sunk and the gravel drifted out has been raised through these shafts to the surface. This method is quite common in Australia, but comparatively rare in California.

When a tunnel has been properly located and the channel opened, drifts are run through the pay ground on both sides and the material is breasted out regular- ly, timbering being employed as the work may require. Shafts must sometimes be raised to the surface for the sake of ventilation.

The gravel is removed through the tunnel by means of a tramway and carried to the mouth, where it is dumped on floors and then washed in the sluices. When too firmly cemented to be broken up by sluicing, the gravel is crushed under stamps.

84 Different Methods Of Mining.

One of the most noted drift-mines in the State is the Bald Mountain, Sierra County, where there is every fa- cility for economical working. There steam locomotives are used for transporting men and material through the tunnel, which is over one and one-fourth miles long.

The following sketches of the workings of the Sunny South Mine, in Placer County, will give a general idea of the method of drift-mining. At this place the main tun- nel is below the channel, allowing the mine to be opened and worked in a very convenient manner.

Drifting was at one time the most extensively used method of deep mining, and through it a very large amount of information has been obtained as to the nature of the ancient river channels.

Hydraulic Mining.— Hydraulic mining is that meth- od of gold-mining in which the ground is excavated by means of water discharged against it under pressure (hy- draulicked).

The term in its limited sense, as generally applied, pre- supposes the existence of, ist, water, in sufficient quan- tity, which can be used under pressure for mining ; 2d, gravel deposits containing gold which can be worked pro- fitably by the application of water in the manner above mentioned.

Origin in California. — The application of the science of hydraulics to the mining of auriferous gra- vels originated in California. The pressing necessity of a more economical process of gold-washing became evi- dent as the rich surface deposits were exhausted, and led to the adoption of this method, which was favored by the topography of the country.

Hydi-anlic vs. Drift Mining. — Deep placers, if suffi- ciently rich, can be, and for various reasons generally are, worked by drifting. But the results of actual practice in Nevada County and elsewhere demonstrate that hy- draulic mining, compared with drifting, employs twice

DIFFERENT METHODS OF MINIiNG.

Cross Section

86 Different Methods Of Mining.

the number of men and extracts four to six times the amount of gold per lineal foot of channel.

The yield of the North Bloomfield channel by drifting has been $150 per lineal foot of channel, while hydraulick- ing the entire deposit in this locality has given a yield of $750 per foot.

Requirements for Financial Success. — From a financial point of view it is essential for profitable hy- draulic mining that there should be ample facilities for grade and dump and a sufficient head and an abundant supply of cheap water, all of which requirements vary in importance inversely with the richness and extent of the gravel. Economical management may be considered in all classes of mining a si7ie qua non to success ; but it is especially requisite here, as the value of this method is based on the great facility with which profitable results can be obtained at trifling cost from expeditiously and skilfully washing vast areas of ground which contain rela- tively insignificant amounts of precious metal.

Strictly speaking, in hydraulic mining, water does all the work, but in the application of this process to the washing of cemented gravel and masses of volcanic pro- ducts, it has been found that water alone has little effect on banks composed of such material, and to overcome this difficulty recourse is had to blasting in order to shatter the bank before water can be advantageously em- ployed.

Chapter Vii. Preliminary Investigations.

In the investigation of all hydraulic-mining enterprises the first problem which presents itself to the engineer is the ascertaining of the value of the gravel deposits. This involves the determining of the course of the channel; the depth and position of the bed-rock, generally covered by hundreds of feet of detritus; the available area for washing ; and the estimates of the yield of the ground, with the calculations of the cost of the work. Accurate information on these points is necessary. But without the assistance of underground explorations few of them can be definitely determined. A study of the geology and topography of the deposit and ot its surroundings aids in determining the course of the channel, the depth of the bed-rock, and the facilities for dump. The value of the gravel can be approximated by sinking small pits, washing the material obtained from them and from such other places as good judgment dictates.

Where the prosecution of an enterprise involves the expenditure of large sums, it is advisable to thoroughly explore the ground by means of prospecting shafts and drifts. Should the results of this work warrant the opin- ion that the ground would pay to hydraulic, then the water-supply and the facilities for dump should be accu- rately determined, with close estimates of the costs.

Indications. — The colors red and blue, with their varying shades, as seen in gravel deposits, are generally considered by miners to be good indications of gold in the different localities. While it is true that these different colored sands often accompany gold, it by no means fol- lows that gold always accompanies them.

Ferruginous colored spots, so well marked in " upper or top gravel,** are not, as a rule, so productive of gold in

88 Preliminary Investigations.

California as they are generally found to be in the Ural Mountains.

A black sand, composed chiefly of glancing grains of magnetic iron, generally accompanies the precious metal, though it occurs also without it.

Dr. T. Sterry Hunt, speaking of the impressions which prevail in reference to the presence of black sand in auri- ferous alluvions, very appropriately remarks that similar black sand residues, consisting chiefly of various ores of iron (sometimes oxide of tin and other minerals), may be obtained from the washing of almost all sands and gra- vels derived from crystalline rocks, and the occurrence of a black sand, therefore, in no way indicates the presence of gold. When, however, this metal is present in gravel, it, from its great weight, remains behind with the black sand and dense matters in the residue after washing.**

Explorations at Malakoff. — The explorations of the North Bloomfield Company furnish a remarkable instance of the extent to which preliminary work has been successfully carried on. To determine the value of their claims and the feasibility of working them, four prospect shafts were sunk to ascertain the value of the gravel, the position of the channel, and the depth to the bed-rock. No. i shaft struck the bed-rock of the main channel at a depth of two hundred and seven feet, one hundred and thirty-five feet of which was in blue gra- vel averaging 41 cents per cubic yard. Drifts were driven from the bottom of this shaft a distance of twelve hundred feet on the course of the channel, the width of which was estimated at five hundred feet. The ag- gregate length of the channel explorations was over two thousand feet. The samples of the various drifts indicat- ed a value of $2.01 per cubic yard. The actual yield of 21,614 tons of gravel extracted from these drifts was $33,- 053.69, or $1.53 per ton, or about $2.75 per cubic yard.

The gross cost of the entire prospecting work, includ- ing the four shafts, was $63,956.20.

Geological Survey of Canada, Report of Progress, 1863-66/* p. 36.

Preliminary Investigations.

Section Of Shaft No. 1. Malakoff

HOflTH BLOOMFIELO ORAVEL MINlNa 00.

0'

Coder Foqjid In ]Bdt.*Ttry fAA

VMi

''S

GiMtdgnnl,

Bio* Grfttvli froBi tcp don ftc aO

*tarH([iiKl AUiqV 1i3 R;to tv lb* pan.

Gold vvf>' Ebc uiUI (rnti vii nfraeik llicni lufi And ua4j*

LM Kf.-vj, 5 t-iy i i>aa to tit jMB

Fir.. 2.

CHAPTER yill.

Reservoirs And Dams.

Storage Reservoirs.

Sources of WateivSupply.— Running streams, melt- ing snows and rains are the sources from which the min- ing districts derive their water-supply. The altitudes of the gravel deposits, two hundred to fifty-five hundred feet above the sea-level, necessitate the bringing of the water from still greater elevations nearer the sources of the streams. The supply from these streams is not always sufficient. Towards the end of winter and during the spring months, while the mountains are still covered with deep snow, rains and temperate weather cause* sudden and rapid thawing, and enormous volumes of water are then discharged from the many water-sheds on the west flank of the Sierra Nevada into the Great Valley of Cali- fornia, and freshets are of quite common occurrence. To make this supply of water available, storage reservoirs have been constructed by some of the large hydraulic- mining companies.

The dry season in California is from May to Novem- ber, but the streams do not run dry until the middle of June or July.

Requirements for Sites. — The principal storage reservoirs in the State are situated at elevations of five thousand to seven thousand feet above the sea-level. The location of a proper site for a storage reservoir is of para- mount importance. In selecting a site especial attention must be paid to the following points:

(i) A proper elevation.

Reservoirs. 9I

(2) The water-supply from all creeks and springs, and the catchment area.

(3) The amount of rain and snowfall.

(4) The formation and character of the ground, with especial reference to the amount of absorption and eva- poration.

All of these points must be thoroughly investigated and determined. It is supposed that the catchment area has been ascertained, and that it is sufficiently large for its minimum discharge to supply all requirements.

Elevation. — The elevation of a reservoir depends upon the location of the mines and the altitude and ex- tent of the country which it is proposed to cover with the ditch. The reservoir should be located below the snow belt wherever possible, and so situated as to obtain the largest water-supply from the catchment area.

Streams. — All the streams should be gauged carefully to determine the minimum and the average supply.

Rainfall. — In new and unexplored localities the wa- ter-supply due to rainfall can be determined only by ac- tual measurement. It cannot be too earnestly impressed upon the engineer that for all such information he must depend on his own observations, which in some cases may require a prolonged stay of a season or more in the field. Under any circumstances rainfall data cannot be relied upon, unless based on many decades of observation.

The rainfall is always greater in mountain districts than in the lowlands. It is greatest on the slopes facing the direction from which the moist winds blow. Definite data of the rainfall of any catchment area can be obtained only by establishing rain gauges at different points, where the observations should be made daily during the season.

Snowfall. — The measurement of the snowfall must be taken on a level, and a given amount of snow reduced to water and calculated for rain.

Absorption and Evaporation. — In reference to the ground, the most desirable formation is that of com-

92 Reservoirs.

pact rocks, like granite, gneiss, or slates. Localities where the formation consists of porous rocks, sandstones or limestones, are not desirable on account of the great loss from absorption.

Steep and denuded slopes are always the best, as but little water will escape. The greatest slope will give the largest available quantity of water. The configuration of the ground influences and affects evaporation, and vegetation causes a large amount of absorption. The losses due to absorption and evaporation are reduced to a ' minimum where the site of a reservoir is in a compact formation with steep sides, and the surface area is conse- quently small. Evaporation varies with the season of the year and the weather (being most active in summer), while percolation, depending on the soil, varies from year to year. Percolation is greatest during melting of snows, and especially when a thaw follows small falls of snow. From reliable experiments made in France and England, the ratio of evaporation to rainfall was determined (1839 to 1852) in the former to have been 76.57 per cent, and in the latter, subsequently, 77. 27 per cent.*

Finally, it must be added that the rule for estimating the total quantity available for storage varies in different districts. In some localities two-thirds of the total amount is estimated to be serviceable, and in others one-third. At the Bowman reservoir 75 per cent, of the total ramfall and snowfall, reduced to rain, is stored.

Beservoir Gauge* — In the construction of reservoirs the location selected must be sufficiently large to hold a supply necessary to meet a maximum demand. The exact area of the reservoir should be determined, and a table showing its contents for every foot of depth made, so that, from an inspection of the gauge and reference to the table, the amount of water available for service can always be known. A longitudinal section through the centre ot the reservoir, with cross-sections and contour lines, five

Harcourt, Rivers and Canals/* p. 3.

Reservoirs. 93

feet above each other vertically, will enable the engineer to determine the height of the dam and to ascertain the contents of the reservoir with the water at any depth.

Reservoir Statistics. — On the head-waters of one of the branches of the Yuba River in Nevada County, at an elevation of fifty-three hundred feet above sea-level, the North Bloomfield Company has established a com- plete system of reservoirs for the storage of water. Their Bowman reservoir and the small ones above it contain about 1,050,000,000 cubic feet of water. The catchment area is 28.94 square miles. The cost of the reservoirs and dams to date is $246,707.51, including the cost of distribut- ing reservoirs.

The Rudyard or English reservoir of the Milton Com- pany since its enlargement contains 650,000,000 cubic feet of water, having a high-water area of 395 acres, fed from a catchment basin of 12.1 square miles. The reservoir is formed by three dams. The back wall of the centre dam has a vertical height of one hundred and thirty-one feet. The walls are of dry rubble stone covering a solidly filled timber crib. The total cost of the reservoir to date is $155,000.

The storage reservoirs of the Eureka Lake and Yuba Canal Company consist of the French reservoir, 661,000,- 000 cubic feet capacity, area 337.32 acres; Weaver Lake reservoir, 100,000,000 cubic feet capacity ; and Faucherie reservoir, 58,800,000 cubic feet capacity, high-water area 90 acres; having, therefore, an aggregate capacity of 819,800,000 cubic feet of water.* The catchment basins of most of these reservoirs are in a rugged, mountainous region, and in ordinary seasons 60 to 80 per cent, of the rain and snow fall flows into the reservoirs.

Distributing Reservoirs. — Independent of these reservoirs, all mines, at convenient distances from their works, have what are called distributing reservoirs, which receive the water from the main ditch for delivery to the

See report of J. D. Hague, M.E., pp. 15, 16, and 17.

94 Reservoirs.

individual claims. These reservoirs are usually small, containing only sufficient water for a few hours* or a few days' run.

The principal distributing reservoirs in the mining dis- tricts of California are :

Waldron, N. Bloomfield Mining Co 5t352,ooo cubic feet.

Marlow, N. Bloomfield Mining Co 1,734,000 cubic feet.

Pine Grove, Milton Mining Co 11,150,000 cubic feet.

Empire, Milton Mining Co 2,230,000 cubic feel.

Excelsior No. i, Excelsior Mining Co 15,610,000 cubic feel.

Excelsior No. 2, Excelsior Mining Co 6,690,000 cubic feet.

Dams.

Dams arc required for the purpose of impounding water in reservoirs, for diverting it from streams, or for storing in the caftons or elsewhere the d6bris coming from the mines.

Foundation.— The first object sought in selecting a site is a foundation sufficiently solid and impervious to prevent settling of the dam, leakage under its base, and wear in front by water running over its top. Where pos- sible the entire foundation should be in solid rock.

A hard, level, compact rock always affords the best foundation, but where that cannot be obtained any thick, impermeable stratum strong enough to sustain the pres- sure will suffice. Gravel soil is better than earth, but re- quires sheet piling to prevent sipage beneath the base of the dam. No reliance can be placed on vegetable soil. In India, where it is impracticable to go down to the bed-rock, stone wells filled with concrete and connected by rows of piles have been used.

In preparing the foundation the soil and all porous material, sand and gravel, is stripped off, and when the solid ground is reached it should be carefully and thor- oughly tested by shafts or borings. Where the rock is fis- sured all loose material should be removed ; some engineers recommend covering the foundation with a layer of pud-

Reservoirs.

Table Ii.

Reservoirs

on the Yuba Bear Feather and American Rivers constructed for mining purposes.

Name.

Bowman

Shot Gun Lake

Island Lake

Middle Lake

Round Lake

Weaver Lake

Eureka Lake

Faucherie

Jackson Lake

Smaller Lakes

English

Fordyce

Meadow Lake

Sterling

Omega and Blue Tent

California

£1 Dorado

Smaller reservoirs on the Feather, Yuba, and American rivers

Total storage.

Owner.

North Bloom field Co,

Eureka Lake Co.

Milton Co

South Yuba Co.

Blue Tent Co. California Co.

Capacity in cubic feet.

930,000,000

3,4238i6

23o27,558

2,3958oo

21907,630

150,000,000

661,000,000

58,800,000

15,000,000

50,000,000

650,000,000

io75,525,ooo

107,950,000

300,000,000

600,000,000

1,070,000,000

700,000,000

6,454,004,804

Note. — The capacities of the reservoirs whose names are given in italics are derived from official sources. The capacities of the other reservoirs are given on the authority of Hamilton Smith, Jr.

96 Dams.

die rammed solidly, which is torn off afterwards, bringing with it all the loose pieces of rock.

Where a hard-pan bottom is used great care should be taken not to crack it. Fanning recommends in such cases that the soil should be carefully removed down to the im- pervious stratum, on which a puddle of well rammed clay, rolled with not less than a two-ton weight, should be placed, and a puddle wall built. He also suggests the covering of the ground in front with a layer of gravel and clay, and at the toe of the inside face of the dam sheet piling should be driven through the hard-pan to prevent any leakage under the base of the structure, which must be water-tight and have a strong apron placed in front of it to prevent the water from scouring the bed.

Wooden Dams. — On light soil, where there is dan- ger of undermining from the overflow, wooden dams can be built in step form (i vertical to 3 or 4 horizontal) and provided with aprons ; sometimes the aprons are inclined towards the dam, against which their lower ends abut, while at the further end sheet piling is driven and the bed around it protected with rip-rap. The same object is accomplished likewise by two dams erected a short distance apart, the lower one forming a pool or water-cushion for the discharge from the upper one.

There are various forms of wooden dams. They are generally constructed of round logs or hewn timber one to two feet in diameter, laid on each other so as to form in plan a series of cribs from eight to ten feet square, and pinned together by wooden treenails. In the bet- ter class of crib-work the timbers are notched and bolted to each other at each intersection with iron drift bolts, the round logs being flattened or notched where they lie upon each other. The bottom timbers are bolted to the bed-rock, the ties are notched and bolted to the stringers, and the cribs are filled with rock. The face of the dam is made water-tight by an outer skin of plank spiked to

Dams. 97

the face ribs. These planks are fitted with an outgauge or battened or otherwise calked.

Abutments. — Where abutments are used they should be constructed so as not to contract the width of the stream. They must be securely connected to the ends of the dam, and, if possible, carried so far inland that high water cannot sweep around them ; they must be sunk deep and protected from all action of the water, and the ends adjacent to the dam should be rounded. They are constructed of stone or cement, or are built of timber cribs.

Masonry Dams. — Hydraulic mining from its nature does not justify the expense of masonry dams, unless perhaps the reservoirs are designed also for other and more permanent uses. The subject of the construction of masonry dams has been thoroughly investigated by engineers. The annexed profile (Fig. 3), the bounding lines of which are logarithmic curves, has been calculated by Prof. Rankine to serve as a type for masonry dams of any practicable height. " It presents many strong points not found in the usual rectilinear profile, and deserves especial consideration,"

The most desirable form of profile for masonry dams is the one which combines the greatest strength with the least amount of material. To determine this it is nec- essary to know the forces to which the proposed dam is to be subjected, whether constant or variable, and the effects they are likely to produce. The conditions of stability (that the dam may sustain its own weight and withstand both its own weight and the pressure of the water) are then considered, and the profile adopted which combines the greatest strength and stability with economy of material.

The weight of the material composing the structure, and the pressure or thrust of the water which it holds, are the only forces which may be regarded as acting with vigor on a dam. The former is constant ; the latter depends on the height of the water behind the dam, and

Dams.

is consequently variable. The thrust at any point acts normally to the immersed surface, and is not uniformly distributed over the entire face, being zero at the water- line and greatest at the foot of the dam.

Fig. 3.

30 so

Section of Dam

60 Feet

Proposed by W. J. M. Rankine, Esq.

A dam may yield by sliding on its base or at any hori- zontal joint, or by rotation about the toe.

In masonry dams the weight of the dam acting verti- cally, and the pressure of the water acting in directions normal to the surface immersed, are the two components of a resultant, and stability will be secured when this

Dams. 99

resultant pierces the base or any horizontal joint within certain defined limits. If the line of the resultant inter- sects any horizontal plane of the dam outside of these limits, stability is not assured.

The following conditions are indispensable for the stability of dams :

1st. The courses of masonry must be incapable of slipping one over the other, and the wall incapable of sliding on its base.

2d. Neither the material employed nor the foundation must be required to bear too great a pressure.

The stones must not be laid in horizontal courses ex- tending from front to rear, and binders should be freely used. The stability of all dams (or walls sustaining pres- sure) requires that there should be no continuous joints.

Earthen Dams. — For reservoirs of moderate depth earthen dams are frequently used. Experience sanctions for these dimensions not less than ten feet on top, and a height of over sixty feet is considered risky by many engineers. Trautwine suggests that in properly con- structed earthen dams the top width should be equal to two feet plus twice the square root of the height in feet." The inner slope should be (base) to i (height), and the outer slope i}i to i. Flat inner slopes are most desirable, as they increase the stability of the structure and likewise prevent displacement of the pitching. In some instances the toes of the slopes abut against retain- ing walls in cement. The inner slopes should be care- fully laced up to the top with dry rubble-stone pitching at least one and one-half feet deep.

The Pillarcitos reservoir, San Mateo County, has an earthen dam six hundred and forty feet long, twenty-six feet wide on top, and ninety-five feet high. The San Andreas dam is six hundred and forty feet long, twenty- five feet wide on top, and ninety-five feet high. The former has a slope of 2% (base) to i (height) on the inner, and 2}i to I on the outer side. In the latter the inner

lOO DAMS.

slope is 3J lo I. and the outer slope is 3 to i. In both cases the puddle walls have been carried down respec- tively forty-six and forty-seven feet deeper than the base.

The materials selected for the embankment play a very important part. The best combination consists of gravel, sharp sand, and clay, properly proportioned, which give weight, cohesiveness, stability, and imper- viousness.* The weight of the wall must be opposed to the thrust, the height and length are determined quan- tities, and the thickness is the only remaining factor for adjustment.

Puddle Walls. — Engineers differ in opinion as to the value of puddle walls. They are designed to prevent leakage through or beneath the embankment and reach from the top to below the base. They should be from six to eight feet thick on top, increasing downwards by offsets at the rate of about one foot for every three or four in depth.

Where the embankment is composed of loose material and the water comes in contact with the clay puddle, it is advisable to enclose the puddle in concrete, or a water- tight wall should intervene between the puddle and the reservoir.

A properly constructed embankment, with the inner slope and the bottom of the reservoir, especially near the toe, securely protected by means of puddle, concrete, or stone facing laid in cement, is considered by some en- gineers preferable to a puddle wall in the centre of the dam.

Shrinkage of Embankments. — The following are the approximate averages of the shrinkage of embank- ments according to Trautwine (1882, p. 630) :

Gravel or sand 8 per cent.

Clay 10 percent.

Loam 12 per cent.

Loose vegetable surface soil 15 per cent.

Puddle clay 20 per cent.

See Fanning, Water-Supply Engineering,*' pp. 33i>-342.

Dams.

lOI

Trautwine determined that one cubic yard of hard rock made on an average 1.7 cubic yards of embankment, or that one cubic yard of rock embankment required 0.5882 of a cubic yard in place. Also that a solid cubic yard when broken into fragments made 1.9 cubic yards of loose heap, if yards carelessly piled, 1.6 cubic yards carefully piled, 1.5 cubic yards very carelessly scabbled, or cubic yards somewhat carefully scabbled.

Dams in California. — Among the most important dams built in California are : the Bowman dam, height one hundred feet, length four hundred and twenty-five

Fig. 4. Dry-stone Dam.

feet ; three dams owned by the Milton Mining and Water Company, forming the English reservoir, the largest of these having a height of one hundred and thirty -one feet ; the Fordyce, of the South Yuba Canal Company, five hun- dred and sixty-seven feet long and seventy-five feet high, catchment basin about forty square miles ; the Eureka Lake dam of the Eureka Iake and Yuba Canal Company, length two hundred and fifty feet, height Sixty-eight feet.

Dams.

TABLE III. Angles of Repose and Friction of Embankment Materials.*

Material.

Dry sand, fine

" coarse

Damp clay

Wet clay

Clayey gravel

Shingle

Gravel

Firm loam

Vegetable soil

Peat

Masonry on clayey gravel . . . .

" dry clay

" moist clay

Earth on moist clay

" wet clay

Angle of Repose.

Coefficient of Friction.

28°

30°

45°

15°

45°

4*°

38"

36°

35°

20°

30°

21"

18°

45°

17°

Ratio of Slope.

H0r. Vert. 1.88 to

1.73 "

I.Oo "

I.Oo "

i.ii "

1.28 "

1.38 "

1.43 "

2.75 "

r.73 "

1.96 "

3.08 "

I.Oo "

See Treatise on Water-Supply Engineering," by J. T. Fanning, p. 345.

Dams. 103

All the foregoing dams are built of dry rubble stone and faced with a water-tight lining of planks.

The Tuolumne County Water Company has built seve- ral timber crib dams, the largest of which is across the south fork of the Stanislaus River. This dam, which is three hundred feet long and sixty feet high, rests for its en- tire base on solid granite bed-rock. The cribs, construct- ed of round tamarack logs from two to three feet in di- ameter, are about eight feet square from log to log (ten feet centre to centre), and the timbers are pinned together with wooden treenails. The cribs have no rock filling.

The face is formed of flattened three-inch timber pinned with wooden treenails to the crib and calked with cedar bark. The flood water passes over the crest of the dam for the entire length. The water is drawn off by several gates, one above the other, placed on the inclined water- face. The dam was built in 1856. Its total cost did not exceed $40,000. Pine dams owned by this company, con- structed on the same plan, have decayed, while cedar cribs are still in perfect order. The Spring Valley and Che- rokee Company's Concow reservoir in Butte County is formed by two earthen dams, each about fifty-five feet in height ; one of these, which is used as a waste, has its lower side built of heavy brush embedded in the earth.

The Bowman Reservoir And Dam.

This reservoir was designed for the supply of water during the dry season of the year to the gravel mines ope- rated by the North Bloomfield Mining Company. It is located in a mountain valley, on Big Cafion Creek, a branch of the Yuba River.

It is fed from a gross catchment area of 28.94 square miles. Higher up on the same stream there are several other reservoirs owned by the Bloomfield and Eureka Lake companies, the upper one (Eureka Lake reservoir) hold- ing 661,000,000 cubic feet of water. In ordinary seasons

Dams.

TABLE IV. Some of the Principal Dams in California*

b U

s'5

Name.

Owner.

£

H

H

u

u

Acres*

Feet,

Feet.

Feet.

Acres.

Bowman

North Bloom-

field Co

$151,521

5,450

Saw Mill Flat.

North Bloom-

§2

field Co

80A

39ft

t

Shot Gun Lake

North Bloom-

field Co

26A

, ,

c

u

6,410

Island

North Bloom-

a-

field Co

48/0

I2A

, .

6,690

Middle "

North Bloom-

field Co

IIto

, ,

§s .

6,460

Crooked "

North Bloom-

i-SS

field Co

lOl'o

6,510

Round

North Bloom-

-Jc 2"

field Co

8A

, ,

o£

6,590

Fall Creek...

North Bloom-

tn

field Co

. ,

6,690

English

Milton M. Co..

6,140

Milton Dam. .

Milton M. Co..

5,67017,637!

Eureka Lake.

Eureka Lake

Co

337A

68A

6,480

Jackson "

Eureka Lake

Co

1C\

Faucherie "

Eureka Lake

Co ! go

, ,

8,000

6,060

Weaver

Eureka Lake Co

83A

21A

Meadow "

South Yuba Co.

7,040

Fordyce (en-

larged)

South Yuba Co. 1200

7,000

Sterling

South Yuba Co.

7,200

Tuolumne Tuolumne Co. .

40,000

8,000

Pillarcitos

Spring Valley

Water Co 1

San Andreas. .

Snring Valleyi

"Water Co

—

♦ Includes cost of the three dams, which form the reservoir. The height and length given are for the main structure.

Dams. 105

these upper reservoirs retain all the water flowing into them, reducing the catchment basin of the Bowman to about nineteen square miles.

The mean annual rain and snowfall at the Bowman dam is about seventy-five inches, of which seventy-five per cent, flows into the reservoir.

Two dams are needed to impound the water. The main one, placed across the narrow gorge forming the outlet of the valley, has a maximum height of one hundred feet (96.25 feet above the datum base line) and an extreme length on top of four hundred and twenty-five feet, and is the largest on the coast.

The smaller dam, placed across a gap near the mouth of the valley, has a maximum height of fifty-four feet and an extreme length on top of two hundred and ten feet. It is fitted with waste-ways, and over it is discharged all the surplus water from the reservoir.

High-water mark is fixed at a point one and one-half feet below the summit of the main dam ; at this height the reservoir contains 918,000,000 cubic feet of water with a surface area of over 500 acres. By placing temporary flush boards on the top of the waste dam the water is raised to the ninety-six feet line (above datum base), increasing the quantity of water stored to 930,000,000 cubic feet.

The stream feeding the reservoir has a maximum flow during great freshets of 5,000 to 7,000 cubic feet of water per second. . The existence of other reservoirs higher up the stream adds to the danger from great floods, and there- fore the Bowman dams have been designed to withstand not only freshets in the cafions, but also any additional in- flux of water caused by the breaking of the upper dams.

Main Dam. — Figure 5 A shows a profile across the cafion, being a longitudinal section through the dam. Figure 5 B gives a cross section at its extreme height.

It rests on solid granite bed-rock, which is sufficient- ly free from seams to prevent any considerable leakage through crevices in the rock.

io6

Dams.

The dam was built in 1872 to the height of seventy-two feet, as shown by the sketch, being a timber crib formed of unhewn cedar and tamarack logs, notched and firmly bolted together, and solidly filled with loose stones of small size. A skin of pine planking, spiked to the water- face, forms a water-tight lining. During the years 1875 and 1876 the dam was increased to the height of ninety- six and one-fourth feet above datum line (one hundred feet extreme height) by filling in a stone embankment on the lower side of the old structure, faced with heavy walls

Section across Cauoii through main dam.

to

AiaioM

a

Do

w

Area tun

—

no

22

—

4n

it

—

Id

-"

m

"''nwr

) 1

2 —5 2 ,*l..l

Fig. 5A. The Bowman Main Dam.

of dry rubble stone of large size. The down-stream face wall is fifteen to eighteen feet thick at the bottom, dimin- ishing to six or eight feet at the top. Most of the face stones in this wall are of good size, weighing from three- fourths to four and one-half tons, and there are many of equal weight in the backing.

The lower portion of the wall is seventeen and one-half feet high, with a batter of fifteen per cent. It is built of heavy stone, with ranged horizontal beds and with the face stone tied to the backing by long iron ties.

The upper portion of the wall is built with a slope of forty-five degrees, and the face stones are bedded on an angle of twenty-two and one-half degrees, thus dividing

Dams.

the angle between a horizontal bed and a bed at right angles to the face. No attempt at range work was made

8h

is

in this upper portion of the wall. Above the sixty-eight feet line ribs of flattened cedar, eight inches thick, are built into the up-stream face wall and are tied to it by iron rods

I08 Dams.

three-fourths inch in diameter and five feet long. On these ribs a planked skin is firmly spiked. This planking is of- heart sugar pine, three inches thick and eight inches wide, with planed edges fitted with an outgauge, similar to ship planking. The plank was put on nearly thorough- ly seasoned, and swells sufficiently to make the face practically water-tight without battening or calking the joints. The openings at the joints made by the outgauge suck in small particles of vegetable matter, which take the place of calking to a great ext(int. At the bottom the plank is fitted to a firm bed-rock and calked with pine wedges. There are three thicknesses (nine inches) on the lower twenty-five feet, two thicknesses (six inches) on the next thirty-five feet, and one thickness on the upper thirty-six feet.

From past experience it is believed that the plank- ing will remain sufficiently sound for twenty years at least.

A culvert extends through the dam, as shown by Fig. 5 B, through which the water is drawn from the reservoir. This culvert is built with heavy dry-rubble foundation and walls, and is covered with granite slabs sixteen to eighteen inches thick and six and one-third feet long.

Three wrought-iron pipes of No. 12 iron, each eight- een inches in diameter, pass through the water-face of the dam. Their upper mouths are protected by a strainer, formed of two-inch plank, anchored to the bed-rock. A separate valve or gate is placed at the lower end of each pipe ; the water passing through the gates, aggregating a flow of 280 cubic feet per second when the three are open, discharges into a covered timber sluice, seven and one- half feet wide by one and three-fourths feet high, passing to the lower edge of the dam, and thence on to the solid rock of the creek bed. The gates are approached by a walk way above the sluice. The crest of the dam is formed by a coping of hewn heart-cedar timber, eight-

Dams. 109

een inches wide on top, securely anchored by iron bolts to the stone wall.

. It is not probable that any water will ever pass over the crest of the main dam, except in case of a break at the large reservoir higher up the stream. Great care was taken in building the down-stream face wall of the |dam for any such possible emergency. Should this hap- pen a large quantity of water would enter the structure, owing to the inclined beds of the face stone and the flat slope of the wall, which water would seek its discharge through the interstices purposely left in the nearly verti- cal portion of the lower wall. To prevent the consequent hydrostatic pressure, which would accumulate at the base of the dam to perhaps twenty pounds to the square inch, from forcing out the lower face, the wall was carefully built and tied with iron rods.

There are 55,000 cubic yards of material in this struc- ture, weighing about 85,000 tons ; the hydrostatic pres- sure, with the water-line ninety-five feet above datum, against a vertical plane of that height across the cafion at the dam site will be 21,745 tons. The dam is built V- shaped, with the vertex of the angle of 165° pointing up stream. This mode of construction adds somewhat to the stability of the structure. The cost was $151,521.44. The rather peculiar construction of this dam was due to the following causes :

The stone cliffs in the vicinky are composed of an ex- ceedingly hard granite with poor cleavage, but with great .numbers of short cross seams, making it most costly to quarry stone of large dimensions.

No limestone existing in the vicinity, the cost of trans- porting lime was so great as to prevent its use.

On the side of the mountain, at the distance of about one mile, there was a large pile of loose stone, too irregu- lar in shape to be used in wall-building, but of good quali- ty for an embankment. It was found to be cheaper to build a tramway to this stone and haul it to the work

no DAMS.

than to quarry from the cliffs nearer the dam. Hence, the supply of material being abundant, flat slopes of 45° for the wall were adopted, which allowed very much lighter face walls to be used with safety than would have been the case had they been more nearly vertical.

The stone for these face walls was quarried from solid rock, and cost in place three or four times more than the loose stone brought from the mountain side. When in the future the timber logs forming the cribs in the origi- nal seventy-two feet dam decay, there will be some slight subsidence of the superincumbent stone. The depth of the stone is so considerable and the slopes of the walls are so flat that it is believed this subsidence will not be noticeable.

Waste Dam. — Figures 6A and 6B show longitudi- nal and cross sections of the waste dam. This is a crib of round cedar timbers varying from twelve to thirty inches in diameter, notched down to heart wood at the joints, and firmly bolted with three-quarter and one-inch drift bolts. The foundation logs are all fastened to the bed- rock with one and one-half inch bolts.

The cribs are solidly filled with granite rocks vary- ing from several tons to a few pounds. No sand or fine stone was used in this filling. A plank facing of three- inch heart sugar-pine is spiked on the water-face, mak- ing a water-tight lining similar to that on the main dam.

The crest of the original dam is ninety-two and one- half feet above datum line, being four feet lower than the summit of the main dam. A light superstructure of four feet allows the water to be raised to the height of the main dam. The waste dam is provided with twenty- eight escapes, each four feet wide and eleven feet deep. These waste-ways are closed, when all danger from fresh- ets is passed, with boards two inches thick, eight inches wide, four and one-half feet long, laid horizontally, and sliding to their places one above the other on the inclined

Dams.

slope of the water-face. This style of gate has been found by long experience to be the best.

The weight of the dam is about 6500 tons, and the hydrostatic pressure, with the water-line 95 feet above

Section across Rayine.

im

Si —

n

hE

;M

r

jk

w

ia

pWtlLJ

— .

Rf

tt!

Ik Ik J

injection tbrongh waste dam.

etijjX WatitrmmrSL.

Wt.

Bedrock

Fig. 6. Bowman Waste Dam.

datum line, against a vertical plane of that height across its upper face, is 2571 tons.

It is believed that the structure is sufficiently stable to allow a flood of 16,000 cubic feet of water per second to pass with safety through the wastes and over its crest.

The water passing over the dam falls on bare granite bed-rock, and thence down a steep gorge.

112 Dams.

From past experience in the use of cedar timber it is safe to assume that the life of this structure will be from t wenty.fi ve to thirty years, and possibly longer. Its cost was $15,000."

D6bris Dams. — Debris dams are obstructions placed across the beds of streams for the purpose of holding back the sand and gravel coming from the mines, to prevent their entering into the navigable streams and damaging the land in the valleys below. They may be placed either in the mountain canons or in the valleys where storage room can be conveniently obtained. These dams or bar- riers may be composed of stone, wood, or brush, as cir- cumstances require. The structures are not designed to impound water, but simply to check the velocit}' of the current carrying the mining and other debris and to allow the deposit of the material behind them, and therefore they partake more of the character of retaining walls than of water dams.

"The deposits in the streams consist of stones several cubic feet in volume — cobble, gravel in all sizes, sand in various degrees of fineness, and a mixture of extremely fine sand and clay, popularly known as slick- ens.' This latter material, being easily transported, is constantly in motion, even in the low stages of the stream. The same is probably also true of the finer sands, and in particular streams is true of the gravel, at least in the upper portions, where the beds are confined and where the slopes are steep.

" When the high stages of water come they find the beds of the streams dotted at the ends of the mining sluices with mounds of detritus, which sometimes form dams across the beds of the stream.

The effect of the flood-water is to sweep these deposits, excepting perhaps the largest pieces of stone, and to carry them away to lower parts of the river. The fall of some of the principal streams serving as outlets to the mines is in places 50 and even 75 feet to the mile. A rise of 20 feet more or less in a narrow bed with such a fall is sufficient to move material with great effect.

"The periods and stages of high water vary very much here as else- where ; but the rainfall, be it large or small — and there is great variation in this respect — comes mainly in two or three months, so that there is, except

♦ The ahovi description of the Bowman dams is essentially the same as that written for the author by Hamilton Smith, Jr., who planned and constructed the danu.

Dams. 113

in very dry years, a period of some length in which the water is high from rains.

"There is also a period of high-water in the spring, due to melting of the snow which has accumulated during the winter on the higher altitudes of the Sierra.

The mass of material thus put in motion in narrow and steep river- beds is carried along to the lower parts of the rivers, each tributary contri- buting its share of flood-water and detritus, and uniting to form at or near the edge of the foot-hills the rivers to which we have given names. As the detritus reaches lower portions, the streams, less concentrated and with constantly diminishing fall in the bed, find themselves unable to carry to the lower course the load which they transported in the upper. When these streams, as they were before mining was begun, reached the plains of the Sacramento Valley, the fall of the beds diminished to a very few feet per mile, perhaps 3 or 4, so that, all along the whole lower course of the river, the bed first, and afterwards the plains bordering the river where the banks were low, became depository places for the material the river was no longer able to carry. The river bed in the plains first becomes obliterated by deposits, and then the alluvial lands adjoining become a waste of sand, gravel, and *slickens.* Instead of a river bed there is a wide plain over- flowed at high stage, through which, meandering in constantly varying channels, the summer river pursues its devious course."*

The topography of the country along the lines of the mountain streams, though rugged, affords every facility for carrying out successfully a plan for storing the tail- ings. The banks are generally of great height, with slopes which vary from fifteen to fifty degrees. The general slope is about thirty-five degrees, and " an elevation of fifty feet adds one hundred and forty to the width, which extended width," says Col. Mendell, " reduces the height of floods, the cubes of the heights being proportional to the squares of the widths. Doubling the width reduces the height one third, which reduction in height reduces the suspending power of the water and the exposure of the structure to floods." f The storage capacity is conse- quently increased by this additional width as the bed of the stream is elevated.

The chief obstacles to be encountered in the erection

Annual Report of the Chief of Engineers U. S. Army for 1881, Appendix MMy. t Col. Mendeirs Report on Mining Debris in California Rivers, p. 41.

114 Dams.

of these dams arise from the present condition of the beds of the streams, the accumulations of past years, and the current mining operations. The channels in their present state contain large quantities of such detritus. In the Yuba alone above Smartsville over 80,000,000 cubic yards are estimated to be deposited in the caftons, and be- tween Smartsville and the mouth of the Yuba some 700,- 000,000 cubic yards are said to be in the bed of the stream. According to the testimony given in the case of Keyes vs Little York Gold Washing and Water Company, 86,000,- 000 cubic yards were estimated in 1878 to have been de- posited in the bed of Bear River above the plains, and 36,- 000,000 cubic yards below the foot-hills to its mouth, a total of 122,000,000 cubic yards.

Without entering further into details of numerous other streams in which d6bris is or has been deposited for the past thirty-five years, suffice it to say that, mining or no mining, it is only a question of time as to when a large part of this mass will move down into the lowlands, un- less measures are taken to prevent the continuous eroding action of the waters and also to impound the material, which can be done only by the construction of a system of permanent dams. Such structures would prevent the streams from eroding the deposits to their original beds, which otherwise, under certain conditions, must sooner or later occur. They would hold in check the accumula- tions of sand and d6bris now stored in the caftons, and would permit the continuation of mining without detri- ment to the interests of others.

It may be asked/' says Col. Mendell, "whether the protection afford- ed in this way will be complete and include all grades of mining tailings. This cannot be claimed. The suspensory matter of fine sands and clay cannot be restrained in this way or by any other method which does not provide a settling basin in which the water can be maintained in a quies- cent state for some* time.

" It may also be expected that during the flood stages in the early period of development a certain portion of material of every grade may be suspended, and thus pass the crest of the barrier ; but it is to be remarked

Dams. 115

that as the width is increased the suspensory power is diminished, so that the degree of protection becomes greater as the system is developed. We can imagine a condition of a river when comparatively little is carried sus- pended, and nearly the whole of the material transported is rolled in waves on the bottom.

This condition is more and more approached as the dams are raised. It seems, therefore, to be good policy to give the first dam in the cafions considerable height.

" It will be understood that permanent protection can be attained only by building dams in proportion to the amount of detritus turned out by the mines. The system must be continued at least as long as the mines are worked.

If this system of restraint had proceeded pari passu with mining dur- ing the past thirty years it can hardly be doubted that the condition of the country affected would to-day have been much better than it is."

The height of floods in the Yuba is only twelve feet at the Narrows, and the water is fully loaded with all the material it is capable of transporting. To insure pro- tection permanent structures are therefore required. On sand or gravel bottoms mattresses of trees or brush may be used to prevent settling ; but where the supply of rock is abundant, convenient, and cheap, masses of stone can be blasted from the side hills, and, by means of derricks or otherwise, be easily arranged as required. The larger the rocks are the better; the largest being put on the down-stream s\de, so placed as to permit the draining through of the water ; the smaller rocks on the up-stream -side. The slopes on both sides should conform to the re- quirements of the structure. As the dam is built the ma- terial will gradually deposit itself against it on the up- stream face ; the water draining through the rocks leaves behind in the dam the sand, which gradually fills up the spaces as the bed of the river is raised. Waste- ways may be readily provided on one or both sides of the dam, which would have the practical effect of lengthening the crest of the dam and of thereby reducing the depth of water passing over it in freshets, in the proportion already

CoU Mendeirt Report on Mining Debris b California Rivers, p. 41.

Il6 DAMS.

stated. This arrangement will lessen the exposure of the lower face and toe of the dam.

In time of great flood the crest will be submerged to a greater or less degree, depending on the width of the structure and the volume of water discharged by the stream. This would be of little consequence, as the work should be especially designed to permit of the flood waters passing over it, the stability of the dam being as- sured by the size and weight of the stones exposed to the water.

The stability of a structure of this character is de- pendent upon conditions differing from those which ap- ply to a structure composed of stones united by a bond, such as an ordinary retaining wall. In the latter case, if the bond is sufficient to make the wall practically a mono- lith, its stabiUty will be complete if it be given weight enough to prevent it from sliding on its base, and such proportions that it can have no motion of rotation about its toe.

The force tending to move or overthrow the bonded dam is equal to the weight of a prism of water whose base is the area immersed, and whose height is the verti- cal distance of the centre of gravity from the water- level. The point of application of this thrust is situated at one-third of the height of the water* measured from the base. The direction of the thrust is normal to the surface.

The problem is an exact one. The thrust is known in its magnitude, its point of application, and its direction, and the problem of proportioning a wall of masonry to resist this thrust admits of complete solution.*

But the detritus barriers are composed of pierres-per- duesy or what is commonly known as rip-rap." There can be little bond in such a structure. Careful placing of stones may, it is true, impart something like a bond, but

See Rankin, Krantz.

Dams. 117

this cannot be safely relied upon as a source of strength. Each stone, being practically independent of its neighbors, must rely upon its own resisting quality to maintain its place in the structure.

It follows that where the floods are great and the ex- posure consequently large the stones must be proportion- ately large and heavy.

The interior of a structure of this kind, being protect- ed from the action of the water and held in place by superincumbent weight, may be composed of sizes of stone which it would be unsafe to place on the crest and exposed surfaces. The stones of the crest and on the lower slope are most exposed, and consequently must be of the largest sizes. The force that tends to move them is not hydrostatic pressure, but the force and impact of great volumes of water moving with high velocity.

Such a structure, composed of rubble stone and unable to impound water, would be exposed to the pressure of the material which is slowly deposited behind it. The maximum horizontal pressure from this source alone would be reached when the plane of fracture of the earth bisects the angle which will be formed by the earth slop- ing back from the foot of the wall on its angle of repose ; therefore the weight of such a prism can be easily cal- culated.

As the dam fills up, the pressure of the material on it- self, owing to its composition, would cause it to consoli- date (cement), thus continually changing the angle of re- pose, until finally, when even with the crest, there would be comparatively no horizontal thrust or pressure on the dam, the structure simply protecting the face of the de- posit from erosion. Therefore such barriers, constructed with proper materials on the well-known principles of dam-building, could not fail to hold back the debris.

As these dams are not water-tight, and are composed of large masses of rubble stone without bond, it is difficult to see how, in the event of a breach, the inhabitants below

Il8 DAMS.

would suffer, nor can it be conceived how a total destruc- tion of the structure could occur. The dam might settle and its usefulness be temporarily impaired, but the only effect that could result in the event of a breach would be a return to the condition of affairs at present existing. As the waters are already charged to their fullest extent, no larger quantity of d6bris could be transported to a greater distance in a single flood. The report of Lieut.- Col. G. H. Mendell to the Secretary of War (1882) treats in detail the remedial measures proposed, and shows " their necessity even in the event that no further con- tribution be made to mining detritus in the beds of streams."

Chapter Ix. Measurement Of Flowing Water.*

Weirs. — The direct measurement of flowing water in a stream or channel can be made in various ways. Occa- sionally gauge wheels are used, but the method is expen- sive. Gauging by rectangular overfalls (weirs) of certain dimensions and under certain circumstances gives results within one per cent, of absolute exactitude (Francis* for- mula).

In employing this method the height above the crest of the surface of still water, some little distance back from the weir, must be carefully measured. It is also de- sirable that there should be no considerable current to the water at the place of measurement.

Orifices. — Flowing water is measured also by its dis- charge under pressure through an aperture of regular section. Though it is not theoretically correct, there will be no practical error in assuming the average head to be from the centre of the aperture when the width is con- siderably less than the height of the water above the top of the opening.

Open Channels.-T-The measurement of the surface velocity of water passing through a flume or canal of uni- form size can be used to determine its discharge, and in some cases the simple calculation of discharge made by

For details on the subject of the measurement of water see The Mechanics of Engineer ing," by Julius Weisbach, translated by E. B. Coxe; Francis* " Lowell Hydraulics" ; "Re- port Mississippi River," by Humphreys and Abbot; "Hydraulic Manual," by Louis D'A. Jackson ; The New Formylae for the Mean Velocity of Discharge of Rivers and Canals," by W. R. Kutter ; " Hydraulic Tables," by Thos. Higham ; A Treatise on Water-Supply Engineering/' by J. T. Fanning ; " Experiments on the Flow of Water," by A. Fteley and £. P. Steams, vol. xii. Transactions of the American Society of Civil Engineers."

"9

120 Measurement Of Flowing Water,

multiplying the mean velocity due to the grade by the average cross section is sufficiently accurate. The dis- charge of small streams is obtained more exactly by fill- ing vessels of known capacity.

Formula for Discharge over Weirs.— In gauging large quantities of water over weirs Fteley and Stearns's general formula can be used for the discharge over the simplest form of sharp-crested weir, unaffected by end contractions or velocity of approach. If these conditions exist the corrections for them must be made separately.*

The formula is

Q 3.3i LH* + 0.007 L

Q is the quantity in cubic feet per second, L the length of the weir, and H the depth on the weir corrected for velocity of approach. This formula does not apply to any depth of the weir less than 0.07 feet.

Discharge througli Triangular Notclies.— The right-angled triangular notch of thin sheet iron is a very convenient way of measuring the discharge of water. According to Prof. Thompson's experiments, the dis- charge in cubic feet per second head (in inches) X

To use the notch, construct a weir box, O, with a tri- angular notch, Y, made of iron, fitted in one end. The edge of the notch must be sharp and bevelled out, and the inside face must be placed at right angles to the surface of the water, M. Place in the box baffle boards or strips, K K, to render the surface of the water near the point A uniform or still (A is taken about 18 to 24 inches back from the weir plate Y). Place a spirit-level or straight-edge C on the weir plate at E ; measure the distance at A from C to surface of water. Subtract this from H, and find the difference in column marked h of Table VII. Opposite A,

See Transactions American Society Civil Engineers," vol. xii. p. 33.

Measurement Of Flowing Water.

in column Q, will be found the number of cubic feet of water flowing over the notch in one minute.

Box

E

THE miner's inch.

Fig. 7. Construction of Triangular Weirs.

The miner s inch of water is a quantity which varies in almost every district in California ; no one gauge has been uniformly adopted, nor has any established pressure been agreed on under which the water shall be measured. In some counties there are 10, 11, or 12 hour inches, and in others there is a 24-hour inch. The apertures through which the water is mea- sured are generally rectangular, but vary greatly in width and length, being from one inch to twelve inches wide and from a few inches to several feet long. The discharges are through i-inch, i-inch, 2-inch, and 3-inch planks, with square or with square and chamfered edges, combined or not, as the case may be. The bottoms of the openings are sometimes flush with the bottoms of the boxes, sometimes raised above them. The head may de- note the distance above the centre of the aperture, or

Measurement Of Flowing Water.

TABI.E VII. Discharge of Water through a RiglU-angled Triangular Notch.

Calculated by W. R. Eckart C.E.

. Q

Q Quantity

k Head,

h Head,

Quantity

I inches.

per min., cu. ft.

inches.

"i'"' inches. ")'"'

inches.

per niin. cu. ft.

1.05 1 0.3457

7.65 49.53

7.70 150.34

22.20j

7.75 151.16

7.80 51.99

7.85 52.83

7.90 53.67

7.95 54.53

8.00 55.39

8.05 56.26

25.87 8.10 57.14'

1.55 10-9153

26.42 1 8.15 58.03 ,

1.60 ,0.9909

8.20 58.92

, 3.85

8.25 59.82

! 3-90

8.30 60.73

8.35 61.65

8.40 62.58

8.45 63.51

8.50 64.45,

3I.O9I

8.55 65.411

8. 60 66.37

8.65 67.34

8.70 168.321

33.60 [ 8.75 ,69.30

34.24 8.80 1 70.30

34.89,1 8.85 171.30

35.56 1 8.90 172.31

' 4.55

8.95 ! 73.33'

9.00 1 74.36 1

9.05 , 75.40

38.27 9.10

38.96:1 9.15

39.67 9.20

40.3811 9.25

41.10;; 9.30 80.71

41.83 9.35 1 81.80

! 5-00

9.40 1 82.90

, 5.05

9.45 . 84.01

17.97 '

9.50 '85.12

18.42 ,

9.55 186.24

18.87 t

9.60 '87.37

1932 '

' 9.65 1 88.52 '

, 5.30

9.70 .89.67;

47.92 j 9.75 90.83

48.72 1 9.80 92.00 1

X cubic foot 7.48 U. S. gals. ; i U. S. gal. 8.34 pounds.

Measurement Of Flowing Water.

Table Viil

Coefficients of Discharge for Rectangular Orifices in thin vertical partitions with greater dimension /lorizotitaL

From Fanning** Treatise on Watcr>Supply Engineering.**

Breadth and Height op Orifices.

Head upon

centre of

Orifice, Feet.

0.75 foot high.

a 50 fool high.

cas foot high. I foot wide.

0.1 as foot high. I foot wide.

I foot wide.

I foot wide.

I.Oo

25*

124 Measurement Of Flowing Water.

again that above the top, and varies from 4J inches to 12 inches above the centre of the aperture.

The Smartsville inch is calculated from a discharge through a four-inch orifice with a seven-inch board top ; that is to say, the head is seven inches above the opening, or nine inches above the centre. The bottom of the aper- ture is on a level with the bottom of the box, and the board which regulates the pressure is a plank one inch thick and seven inches deep. Thus an opening two hun- dred and fifty inches long and four inches wide, with a pressure of seven inches above tjie top of the orifice, will discharge 1000 Smartsville miner s inches. Each square inch of the opening will discharge 1.76 cubic feet per minute, which approximates the discharge per inch of a two-inch orifice through a three-inch plank with a head of nine inches above the centre of the opening, the said dis- charge being 1.78 cubic feet per minute. The Smartsville miner's inch will discharge 2534.40 cubic feet in twenty- four hours, though in that district the inch is reckoned for eleven hours only.

Other Inches. — The miner's inch of the Park Canal and Mining Company, in El Dorado County, discharges 1.39* cubic feet of water per minute. The inch of the South Yuba Canal Company is computed from a dis- charge through a two-inch aperture, over a one and one- half inch plank, with a head of six inches above the centre of the orifice.

At the North Bloomfield, Milton, and La Grange mines the inch has been calculated from a discharge through an opening fifty inches long and two inches wide, through a three-inch plank (outer inch chamfered), with the water seven inches above the centre of the open- ing.

Determination of the Inch; Experiments at Columbia Hill. — To determine the value of this miner's inch, a series of experiments was made at Columbia Hill,

Estimated by J. J. Crawford, M.E.

Measurement Of Flowing Water. 12$

latitude 39" N., elevation 2,900 feet above the sea-level. The module used was a rectangular slit fifty inches long and two inches wide, with head seven inches above the centre of the opening. The dis- charge was over a three-inch plank, the outer inch chamfered, as shown in Fig. 8. The size of the opening was taken with a measure (micrometer attached) which had been compared with and adjusted to a standard United States yard. Time was r .

read to one-fifth of a second ;

;4

the level of the water (drawn fig. 8.

from a large reservoir) was de- termined with Boyden's hook, micrometer adjustment. The following results were obtained :

One miner's inch will discharge in i second .026 cubic feet.

The coefficient of efflux is 61.6 per cent. These figures are within the limit of possible error.*

As the two-inch aperture requires too much space for gauging large quantities of water, custom has changed the form of the module, and an aperture twelve inches high by twelve and three-quarter inches wide, through a one and one-half inch plank, with a head of six inches above the top of the discharge, is now used. These openings discharge what is accepted as 200 miner's inches.

A series of experiments was made at La Grange, Stanislaus County, California, latitude 37° 41' N., eleva- tion 216 feet above the level of the sea, to determine the value of the inch thus delivered in the claims. The re- suits here given are the mean of a series of gaugings

The experiments were made in 1874 by H. Smith, Jr., C.E.

126 Measurement Of Flowing Water.

taken from nine different apertures, discharging in the aggregate i,8oo miner s inches.

The water was drawn directly from a flume and dis- charged into a small reservoir, across the lower end of which was fitted a gauge. The velocity of the water issuing from the flume was broken by several drops as it entered the reservoir, and the gauge at the lower end was raised sufficiently to prevent any flow due to an increased velocity which might have been acquired in the flume.

The level of the water was determined with a Boy- Qen*s hook.

The discharge from the module was caught in a flume and conducted to a box fitted and levelled for the pur- pose. Time was read to one-fifth of a second. The fol- lowing results were obtained :

One miner's inch discharged in i second .02499 cubic feet.

" " I minute 1.4994 "

Effective coefficient of efflux, 59.05 per cent.*

An experiment on a single aperture of this form, made by Hamilton Smith, Jr., gave a discharge of 2179.4 cubic feet per miner's inch in twenty-four hours. The 2,230 cubic feet of the North Bloomfield inch can only be con- sidered an assumed rough estimate of discharge in twen- ty-four hours for one miner's inch.

The theoretical velocity, in feet per second, of a fluid flowing into the air, through openings in the bottoms or sides of a vessel or reservoir, the surface level of which is kept constantly at the same height, is equal to that which a heavy body would acquire in falling through a space equal to the depth of the opening below the surface of the fluid, and is expressed as follows :

The experiments were made by the author.

Measurement Of Flowing Water. 12/

In which z/= velocity in feet per second. acceleration of gravity. A=the height fallen in feet.

This is called Torricelli's theorem, which supposes in- definitely small orifices with thin sides, and assumes that the upper surface of the water and the orifices are under the same conditions as regards atmospheric pressure. Conditions and size of sectional area of the aperture, fric- tion, resistance of the air to motion, and pressure of the atmosphere are all neglected.

The value of g varies in dififerent latitudes, but for all practical purposes is taken as equal to 32.2.

The theoretical head=--

The acceleration of gravity at latitude 45° =32. 17 feet per second, being represented by g; for any other lati- tude, /.

'=(1—0.002588 cos 2/)*

If g represents the acceleration of gravity at the height h, and r the radius of the earth, the acceleration of gravity at the level of the sea equals

Flow of Water in Open Channels.— There is no

generally accepted formula for determining the velocity of water in open channels. The tables based on the old formulas published prior to the works of D*Arcy and Ba- zin in France, and of Humphreys and Abbot in the United States, being founded on data which ignored the important factor of the nature of the bed and the sides of the channel, have proved unsatisfactory. Hydraulic en-

See professional papers, Corps of Engineers U. S. A., No. xa, page 96.

128 Measurement Of Flowing Water.

gineers have been compelled to rely for correctness of calculated results on the application of a combination of a few known laws with experimental data, which latter, though all-important, have been too restricted for the de- duction of a reliable mathematical theory.

The formulas, in terms of dimensions of cross section and slope, are based upon the supposition of either " per- manent or " uniform " motion. Permanent motion ap- proaches the condition of streams, permits changes of cross section and slope of the water-surface, excepting sudden bends, causing eddies and undulations, but de- mands that the discharge from the different sections should be identical. Uniform motion, in addition, requires an invariable cross section and constant slope of the fluid- surface. The general formulas based on permanent mo- tion differ from those restricted to uniform motion, by taking into account changes of living force produced by changes of cross section at the different points." If there are no variations, the difference between the for- mulas disappears.

Chezy considered that the resistances encountered by water in uniform motion were in direct proportion to the length of the wetted perimeter, to the length of the chan- nel, and to the square of the mean velocity ; from which he deduced the formula,

V is the mean velocity in feet per second. c a coefficient taken at a constant value. r the mean hydraulic radius in feet. s the fall of surface in a unit of length.

The equation indicates the relation of the mean veloci- ty to the slope and the mean hydraulic radius. The value of the coefficient c has been empirically demonstrated to

Humphreys and Abbot, Mississippi Report, p. 207.

Measurement Of Flowing Water. 1 29

have a wide range. This formula, however, has been considered the simplest, and has been used by many engi- neers, different values being given to r, varying from 84 to 100 for large streams, and being as low as 68 for small streams. " Though there is abundant evidence/* says Higham (p. 5), " that the latter is much too high for low values of v in earthen channels, and that 100 is too low for very large rivers, as high a value as 254.4 having been deduced from the Mississippi observations."

D'Arcy and Bazin, by their experiments on channels of moderate section with limited variation of grades, proved that the coefficient c involved not only r and j, but also a constant for the different degrees of roughness of the channel, the formula being applicable within certain limits of inclination and values of r.

Humphreys and Abbot make the velocity vary with the fourth root of the inclination, while Hagen assumes the velocity to vary with the sixth root.

Ganguillet and Kuttcr considered that the Chezy formula, v=c vvas the correct point of departure, but that the coefficient should be made variable, involving not only r and j, but likewise a constant for different de- grees of roughness in the bed or channel.

The final formula adopted by Ganguillet and Kutter, which within certain limits of inclination, and especially in regular channels, will give very satisfactory results, is the following:

, 1. 81 1 , 0.00281

v=.

rs

The coefficient of roughness, N, is dependent on the nature of the beds and sides. The useful values of this coefficient are as follows :

I30 Measurement Of Flowing Water.

Nature of Sides of Channel. Coefficient of Roughness.

Well planed timber A''=o.oo9

Plaster in pure cement o.oio

" " cement one-third sand o.oii

Unplaned timber 0.012

Ashlar and brick work 0.013

Canvas lining on frames 0.015

Rubble 0.017

Canals in ver>' firm gravel 0.020

Rivers and canals in perfect order and regimen, and perfectly

free from stones and weeds 0.025

Rivers and canals in moderately good order and regimen, having

stones and weeds occasionally 0.030

Rivers and canals in bad order and regimen, overgrown with

vegetation and strewn with stones or detritus of any sort. . . . 0.035

Torrential streanls encumbered with detritus 0.050

Ditches in California.— In the mining districts of California ditches are constructed boldly, with steep grades and on irregular lines with numerous sharp curves. The cross sections, originally uniform, become more or less varied. Absorption, percolation, evapora- tion, and leakage reduce the flow. A distinct, reliable factor for each of these sources of loss cannot well be in- corporated in the coefficient of discharge. If, then, it is intended to cover all of these common sources of loss by such a coefficient, its value must be a material modifica- tion of values commonly given in the text books. It would be certainly an affectation of accuracy to apply so complicated a formula as that of Kutter in such a case, since the modifying conditions, which can be estimated but roughly, call for a large reduction of the calculated result. This will be apparent from the measurements of discharge given further on. The simple formula, Q acVrSj expresses more fitly the result of experience in such cases, wherein —

Q is the quantity of water which the ditch is capable of carrying in cubic feet per second.

a the effective area of cross section of ditch, as origin- ally constructed, in square feet.

Measurement Of Flowing Water. I3I

r the hydraulic mean depth in feet. s the fall of surface in a unit of length. c a coefficient covering all common losses.

Examples of Value of Coefficient in Ditches. —

In its application to the North Bloomfield main ditch* (length 40 miles, sectional area 23.89 square feet, grade 16 feet per mile), with its abrupt turns and sinuous course, the value of the coefficient r, as determined, varies from 44.7 to 37.7 in accordance with the season of the year.

The Texas Creek f branch ditch is about seven-tenths of a mile long. Its sectional area is 13.5 feet and the grade is 20 feet per mile. The sides are rough and the curves are sharp. With a flow of 32.8 cubic feet per sec- ond, the ditch runs about full. The value of r 33. In connection with this ditch there is a rectangular flume 2.67 feet wide X 2.83 feet deep, made of unplaned boards, set on a grade of 32 feet per mile. The flume has some sharp but regular curves, and the water from the ditch runs it nearly full at these points. With the discharge 32.8 cubic feet per second, r=: 59.

On the Milton line, from Milton to Eureka, a distance of 19.4 miles, the sectional area of the ditch is 20.39 square feet, grade 19.2 feet per mile for the earthwork and 32 feet per mile for flume. The line is very irregular, hav- ing many drops and chutes. The distance from Milton to the measuring box at Bloody Run is 29 miles. The minimum established grade for the last 10. i miles was 16 feet per mile, with a sectional area for the ditch of 23.05 square feet. The coefficient r, determined from the gaug- ing at the measuring box, has varied from 22 in its leakiest condition to 31, which latter can be taken as correct for the present condition. In the succeeding 30 miles below the gauge, owing to a better character of ground, the co- efficient reaches 41.

Increased capacity of this ditch is limited by the pipes across Humbug Cafion. t For deuils of Texas Creek ditch and flume see paper by Hamilton Smith, Jr., Trans- actions Am. Soc. C.E./* vol. xiii. pp. 30-31.

132 Measurement Of Flowing Water.

The La Grange main ditch, 17 miles long, has a sec- tional area of 22.5 square feet, and a grade of 7 feet per mile. From the delivery, 56.5 cubic feet per second, at its Patricksville junction the coefficient c is determined to be 52, but it is based upon the assumption that the depth of the canal is 3 feet, whereas in the original construction ' it was supposed to have been made 4 feet deep ; the dis- charge therefore due to such a sectional area would nec- essarily diminish the ascribed value of

In all these canals, after the artificial banks are well consolidated, the water area is increased beyond the ori- ginal excavation in the natural ground.

Accuracy cannot be expected in calculating the values of Q for proposed ditches of such character. Important losses must vary in every ditch, depending on the nature of the ground, and the character of the construction of the work, and the season of the year. The feeders along the lines largely compensate for these losses. In order to be safe in estimating the capacity of a ditch, the value of the coefficient c for the dry season should be taken.

The following facts show the magnitude of the losses due to absorption, leakage, evaporation, etc.

Three thousand miner's inches of water (a flow of 75 cubic feet per second) turned in during the dry season at the head of the Bloomfield ditch will deliver 2,700 inches (67.5 cubic feet per second) at the gauge 40 miles distant. 2,400 inches of water (60 cubic feet per second) turned in at the head of the Milton ditch formerly delivered at the gauge, 29I miles distant, 1,450 to 1,600 inches (36.25 to 40 cubic feet per second) ; but at present 2,500 inches (62.5 cubic feet per second) turned into the head of the ditch delivers 2,000 inches (50 cubic feet per second) at the gauge. The exact loss of water between the head of this ditch and the measuring box is shown in the following

The grades given in all the above cases, from which the different values of c were calcu- lated, are otherwise independent of the drops, chutes, flumes, etc Sectional areas represent minimum cross sections.

Measurement Of Flowing Water. 1 33

summary, taken from the official records for the month of August for the years 1875 to 1882 inclusive. This month is taken as a dry month, as prior to that time the nume- rous side streams swell the amount delivered at the gauge :

Record For August.

Water turned in at Milton, — Water record at Bloody Run.- Year. a4-hour inches. 94-hour inches. Per cent.

1875 44.000 34,950 79.4

1876 59.700 42,625 71.3

1877 67,875 44,700 65.9

1878 70,050 58,875 77.4

1879 . 82,725 51.350 62.0

1880 74,080 55.325 74.7

1881 66,850 48,325 72.3

1882 68,300 50,984 74.4

The Eureka Lake ditch, with 2,500 inches turned in at the head, delivers at the gauge, 33 miles distant, about 1,800 inches in the dry season.

The above statistics lead to the adoption of values of the co-efficient r, varying from 31 to 45, in estimating the capacity of ditches* on heavy grades of forty miles length flowing from sixty to eighty cubic feet per second, such as referred to — that is :

(2 31 to 45 tf Vr7

The loss incurred in the distribution of water is de- noted by the following figures, taken from the official records of two mining companies. The amount received is measured at or near the distributing reservoirs; the amount used, at or near the pressure boxes. The differ- ence shows the losses from leakage, evaporation, absorp- tion, and wastage arising from excess of constant sup- ply over the amount needed, with interruptions at the claim :

These ditches are constructed on the rough mountain sides in rock more or less disin- tegrated.

134 Measurement Of Flowing Water.

North Bloomfield Company (34-Hour Inches).

Year. Amount Received. Amount Used. Loss.

187010 1879, incl,. 51838,865 5,504.758 334,107=6 per cent.

1880 945.550 920,612 24,938=2

1881* 950,340 866,962 83,378=9

1882 1,025,880 1,005,977 19,903=2

1883 862,660 836,251 26,409=3

14 years 9,623, 295 9, 1 34. 560 488, 735=5 per cent.

Milton Company (24-Hour Inches).

1882 685,933 635,884 50,049= 7 per cent.

i883t 446,224 361,877 84,347=19

2 years 1,132,157 997,76i 134,396=13 per cent.

*Much water ran to waste during four months, owing to cessaticm of work caused by litigation.

t English reservoir, from which source the main water-supply was obtained, was de- stroyed June 18, 1883.

Chapter X.

Ditches And Flumes.

Ditches.

The demand for water throughout the mining districts has caused the construction of thousands of miles of ditches. The cost of these has been immense, but the returns on legitimate enterprises have well repaid the capital invested. On account of the rugged character of the country traversed by the ditch lines, in order to lessen the cost and expedite the work, steep grades were used, high trestles were built (in some instances supporting large flumes at elevations of two hundred to two hundred and fifty feet), and wrought-iron pipes were introduced for conveying the water across the valleys and cafions. The boldness with which these works were undertaken was characteristic of their originators.

liocation aud Construction Principles.— In lo- eating and constructing ditches the following rules should be observed :

(i) The source of supply should be at sufficient eleva- tion to cover the greatest range of mining ground hi the smallest expense, great hydrostatic pressure being always desirable.

(2) An abundant and permanent supply of water dur- ing the summer months should be secured.

(3) The snow line, when possible, should be avoided, and the ditch, especially in snow regions, located so as to have a southern exposure.

(4) All water-courses on the line of the ditch should be secured ; their supply partially counteracts the loss by evsporaEtion, leakage, and absarptkm, and frequently fur-

136 Ditches.

nishes an additional quantum of water during several months of the year.

(5) At proper intervals waste-gates should be arranged so as to discharge the water, when necessary, without risk of damage to the ditch. In regions of heavy snow these waste-ways should be provided at intervals not greater than one-half a mile.

(6) Ditches, when practicable and the cost not being excessive, should be preferred to flumes.

Surveying a Ditch liine.— In the preliminary ex- amination for the location of a long ditch, by means of careful comparative observations made with good aneroid barometers, the elevations not only of the termini, but also of intermediate points from which different surveying parties can start on the subsequent location of the line, can be approximately determined.

The various necessary points once established by sur- vey, the line is staked. In levelling, all turning points should be made on grade. The stations should be pro- perly numbered and staked, and pegs driven to grade. Every four or five stations the rodman should be required to call oflf the reading of the rod, which is checked by the notes of the surveyors. Stations may be from fifty to one hundred feet apart on ordinary ground, but a very irregular country demands shorter intervals, sometimes of a rod only. Bench marks should be placed every one- fourth or one-half mile for convenient reference.

All details of tunnels, cuts, and depressions which re- quire fluming or piping should be worked out in full. In this work the hand level can often be employed with ad- vantage. Complete notes should be made of the charac- ter of the ground along the entire line, and also of any possible changes.

The size of a ditch is regulated by its requirements. Its form will be modified often by circumstances of which the engineer is the judge. The smallest section for any given discharge is when the hydraulic mean depth is one-

Ditches. 137

half of the actual depth. As a general proposition, this is the most economical form of profile for water-channels with given side slopes. The amount of excavation is the least in that channel where the wetted perimeter for a given area is the smallest. In practice the forms common- ly adopted for ditches and flumes are trapezoidal and rect- angular.

With rectangular profiles the resistance due to friction is the smallest when the width is twice the height.

Of trapezoidal profiles, the half of a regular hexagon is generally used in canals and ditches.

Circular and square profiles are employed only in stone, wood, and iron constructions.

Narrow and Deep vs. Broad and Shallow Ditches* — In a mountainous country narrow and deep ditches with steep grades will generally be found prefer- able to large conduits with gentler slopes. The first cost of excavation is much less, as is also the cost of repairs rendered necessary by snows and severe storms, the nar- rower aqueduct being more easily protected. The ex- perience of the ditch-builders in this State has been uni- formly favorable to these steep grades, but little trouble being caused by the washing of the banks due to high velocities. In the valleys with ashy soil such grades, of course, would not be practicable.

Ditches in California with carrying capacities as large as 80 cubic feet per second have been built, and are now in successful operation, with grades of sixteen to twenty feet per mile.

Excavating the Ditch. — Before the work of exca- vating is commenced the line is cleared of trees and un- derbrush for a sufficient width to render work afterwards easy and to prevent subsequent damage to the ditch. All trees which are liable to fall and injure the work should be removed before construction begins. On a flume line the brush for at least ten feet on each side is burned as a precaution against fire. So far as possible, and especially

138 Ditches.

along a side hill, the ditch should be dug so as to have walls of solid, untouched ground, and not made banks. The top of the solid bank on the lower side should be fully three feet wide. In such cases the top soil is first re- moved for the width of the ditch and bank ; the material excavated to form the ditch is used to raise the lower bank, and in time consolidates to firm ground, thus in- creasing the capacity of the ditch.

The digging of ditches is usually let by contract at a given sum per rod, and heavy cuts per cubic yard. It is customary to excavate large ditches with a slope of 60° for the upper and 65° for the lower bank. These slopes, of course, the engineer will vary in accordance with the ground encountered. In practice they are changed even- tually by erosion and denudation ; but experience seems to warrant the above-mentioned slopes as the best to be adopted in laying out such works.

In large mining ditches constructed with high grades and running large amounts of water, the erosion and con- sequent enlargement of the ditch (when kept in order) is noticeable ; moreover, the banks gradually become solidi- fied, and thereby the loss by leakage and absorption is de- creased. It is roughly estimated that the capacity of a well-constructed ditch which is properly kept up is in- creased about 10 per cent, in eight years.

Ditches poorly built in the beginning subsequently require large and constant expenditures, and lose con- siderable amounts of water. The annual cost of running and maintaining large ditches, including all repairs and taxes, is estimated to be $400 per mile.

Examples of Ditches.- Among the principal ditches in the State are the North Bloomfield, the Milton, the Eureka Lake, the San Juan, the South Yuba Canal, the Excelsior or China ditch, the Bouyer, the Union, the El Dorado, the Spring Valley and Cherokee, the Hendricks and the La Grange.

Uortli BleennAeld. — The North Bloomld main

Ditches.

ditch, including distributers, is fifty-five miles long. Its size is 8.65 feet on top, 5 feet at bottom, and feet deep. The ditch and distributers cost $466,707. Its grade is six- teen feet per mile, discharging 3,200 miner's inches.

Milton Com- pany. — The Milton Company's ditch- es are eighty-four miles long, and their grades are from twelve to thirty- two feet to the mile. The size of the main ditch is 4 feet on the bottom, 7.6 feet F'- 9- North Bloomfield Main Ditch. deep, discharging 3,000 miner's inches ; cost, $462,998.

Grade 19? Ft. Per Mile.

Fig. 10. The Milton Ditch.

Eureka Lake.— The Eureka Lake main ditch is eighteen miles long and has a capacity of 2,500 miner's

I40 Ditches.

inches. Its cost, including water rights and flumes, was $256,003. The San Juan ditch and branches extend some forty-five miles in length ; the main ditch is thirty-two miles long, and its capacity is 1,300 miner's inches. The cost was $292,992. These two last mentioned ditches be- long to the Eureka Lake and Yuba Canal Company.

South Yuba Canal Company. — The main ditch of the South Yuba Canal Company (from the head of Bear River) is one and one-half miles long, six feet wide on top, and five feet deep, with a grade of thirteen feet per mile. Its present capacity is said to be 7,000 miner's inches. From Bear Valley (the junction of the main and the Dutch Flat ditches) the size of the canal for the succeeding thirty-one and one-half miles is six feet wide on top, four and one-half feet deep, with a grade of eight feet to the mile. The Dutch Flat ditch is thirteen miles long ; it is six and one-half feet wide on top, four feet deep, and has a grade of thirteen and one-half feet per mile. The capacity of this ditch is 3,150 miners inches. The Chalk Bluff ditch is six feet wide on top and five feet deep, with a grade of sixteen feet per mile, and has a capacity of 4,100 miner's inches. The several ditches owned by the South Yuba Company have an aggregate length of one hundred and twenty-eight miles.

Smartsville Ditches.— The Excelsior, or China, ditch at Smartsville is thirty-three miles long, five feet wide at the bottom and eight feet on top, and is four feet deep. The grade is nine feet to the mile, and the ditch discharges 1,700 Smartsville miner's inches.

The Bouyer and Union ditches are each about fifteen miles long, four feet wide on the bottom, eight feet on top, and three and one-half feet deep. Their grades are thirteen feet to the mile, and each discharges 1,200 Smarts- ville miner's inches.

There are several minor ditches which deliver wa- ter in and around Smartsville. The total capacity of all these ditches is 5,000 Smartsville miner's inches, and the

Ditches.

whole investment in this class of property approximates $1,200,000.

Spring; Valley. — The Spring Valley and Cherokee ditch is fifty-two miles long and has about four miles of iron pipe thirty inches in diameter. The size of the ditch averages five feet wide, three and one-half feet deep, dis- charging about 2,000 inches of water.

Rade Ft. Per Mile

Fig. II.

La Grange Ditch.

Fig. 12. Section of Wall Ditch on Line of La Grange Mining Company's Ditch.

Hendricks. — The Hendricks ditch, in Butte County, is forty-six and one-half miles long; grade of the upper line of ditch, 12.8 feet per mile ; grade of the lower line, 6.4 feet per mile; dimensions, 5 feet wide, 2 feet deep.

142 Flumes.

Total cost, including Glen Beatson ditch and Oregon

Gulch ditch, $136,150*

La Grange. — The La Grange ditch,t including the

Patricksville branch, is over twenty miles in length.

Size, nine feet on top, six feet at the bottom, four feet deep ; grade, from seven to eight feet to the mile. The greater part of the ditch is cut in granite, and in places there are solid stone walls fifty

Fig. 13. La Grange Flume. Crossing seventy feet hih.

It discnargea 2,400 mi-

ner's inches at the date of last measurement, and its cost

was over $450,000. Its capacity was formerly larger, but

the ditch is now in a bad condition.

Flumes.

In general, the use of flumes is to be avoided where- ever possible, long experience demonstrating that they are not economical, being too liable to destruction from fire, wind and snow storms, and by decay. Hence they are a source of continuous expense.

Flumes vs. Ditches. — There are instances where the formation of the country requires the use of flumes rather than ditches ; for example, where the water must be conveyed along the face of vertical cliffs, as in the case of the Miocene Gold-Mining Company in Butte County. There are also certain conditions of the formation of the ground, independent of the topography, where a ditch cannot be employed so economically as a flume — viz., when the ground is composed of either very hard or very

See Raymond's Report, 1873, pages 73 and 74.

t The original ditch, about nineteen miles long, is said to have cost $375,000. Since its completion the Patricksville ditch and reservoir have been built at a cost,of $75,000.

Flumes.

porous and shattered material. Likewise where water is scarce and the evaporation and absorption are great, flumes must necessarily be preferred. In such cases as these either flumes or pipes may be advantageously used.

Grades. — Flumes are set, where practicable, on grades of twenty-live to thirty-five feet per mile, and are consequently of proportionately smaller area than ditches.

The annexed sketch shows the general style of con- structing flumes.

Planking The

planking used ordi- narily is of heart su- gar pine (seasoned) one and one-half to two inches thick, twelve to twenty-four inches wide, accord- ing to the require- ments, and twelve to sixteen feet long, the twelve-foot length be- ing the most desirable.

Sills and Posts. — Where the boards join, pine battens three to four inches wide, one-half inch thick, cover the seams Sills, posts, and caps strengthen the structure every four feet. The dimensions of the timbers depend on the size of the flume. A flume two and one-half feet square requires 3X4 inch scantling for posts, caps, and sills, and 4x6 inch for the stringers ; while a flume 4X3 feet in the clear should use 4X5 inch stuff for the caps and posts, sills 4x6 inches, with string- ers 10X8 inches in size. These sizes are used in regions

Fig. 14. Flume Construction.

144 Flumes.

of heavy snow, and can be reduced somewhat in milder localities.

The width of the flume regulates the length of the sills and caps, and the length of the posts is determined by the depth of the flume, three inches or less being allowed between the top of the planks and the cap. In larger flumes these different sizes are slightly increased.

The posts should be set into the caps and sills with a gain of one and one-fourth inch, and not mortised. The sills generally extend from twelve to twenty inches be- yond the post (according to the size of the structure), and to them side braces are nailed to strengthen the structure, although these side braces are generally unne- cessary in properly constructed flumes. In the mountain regions snow and ice frequently attach themselves to the braces and sills, breaking them off and occasionally de- stroying the flume. On top of the caps there is placed a foot plank eight to ten inches in width.

Flumes should be placed on a solid bed on the re- quired grade. To avoid damage from slides, or snow and wind storms, the bed should be excavated in the bank of the side hills and the flume placed close to the bank. Stringers running the entire length of the flume are placed beneath the sills immediately outside of the posts. They are not absolutely necessary, but are desirable, as they preserve the sill timbers from decay.

Curves. — When curves are necessary they should be laid with great care, so as to insure the maximum flow of water. The boxes must be cut in two, three, or four parts, as the case may demand. This necessitates an in- crease in the number of sills, posts, and caps. To secure the better curving of the side planks they are sawed par- tially through in different places, so that they bend easily, the sawed portions closing thoroughly by the curving of the plank.

To distribute the water equally over the entire flume and prevent slack water, irregular currents, and splash-

Flumes. 145

ing, the outer side of the flume is raised in accordance with the curve. No rule can be given for the exact amount of rise, but it can be readily determined by wedging up the flume. This is very essential in cold climates, as ice forms where any splashing occurs.

Waste-Gates. — Waste-gates should be placed every half-mile, so that the water can be readily turned out, as may be required from time to time, and are especially necessary in case of any accident. They should dis- charge the water clear of the line to prevent any under- mining. They are useful also for clearing the canal of snow and ice.

Precautions against Cold. — In the snow belt the flumes are covered with sheds in the most dangerous places where they are exposed to snow slides. The most approved form of snow shed consists of sets of timber 4X6 inches to 7x9 inches in size, placed at intervals of four feet and covered with boards or lagging. Where the flume is set in close to the bank the circulation ol air around it during the winter is partially prevented by snow, and freezing of the water is not so probable as where the flume is exposed on all sides.

Great difficulty is experienced sometimes in keeping flumes and ditches open during long continued very cold weather, on account of the formation of anchor ice on the bottom. When this occurs it is necessary imme- diately to turn out the water, otherwise they will fill up solidly with ice and remain closed until spring. Should snow fill the flume when empty, it can be readily run out if the water is turned on before it is allowed to pack.

In Nevada County, at the head of the Bloomfield ditch, the snow falls in depths of from six to thirteen feet on a level. The temperature ranges as low as zero, but ordi- narily has a winter mean of 30° Fahr. The Bloomfield ditch, carrying 80 cubic feet of water per second, is sel- dom troubled by the forming of ice or snow blockades. This ditch is supplied from a reservoir, the water of

146 FLUxMES.

which is of a temperature of 36° Fahr. The canal for the first twenty miles collects but little snow even during heavy storms ; in the lower twenty miles, the water hav- ing become more chilled, snow collects rapidly at times, and the ditch has upon a few occasions been blockaded.

Other ditches in the same locality, of nearly equal ca- pacity, but lying on the cold north hillsides and drawing water from creeks and rivers, have great difficulty in running water in cold, stormy winters, owing to the formation of ice, snow slides, and snow blockades.

The head of the Milton ditch being on the north side of a cold caflon, the temperature at times falls as low as Fahr. Notwithstanding this excessive cold, the ditch is kept open the greater part of the winter when there is a sufficient supply of water, and with a flow of 80 cubic feet per second probably but little difficulty would be experi- enced in keeping up a constant supply.

Experience in tlie Blaclc Hills.— In the winter of 1 879-80, on the line of the Wyoming and Dakota Water Company's open flume, at the head of the Spearfish River in the Black Hills, Dakota, with the mercury ranging from 5° to (Fahr.) below zero, no difficulty was experienced in running the water a distance of about six miles (the portion then finished) during the entire season, the tempe- rature of the water varying from 42° to Fahr.

On one occasion the thermometer reached 43° below zero, as indicted by the spirit thermometers, the mercu- rial thermometers bursting at Fahr. The temperature of the water at this time fell to Fahr. The extreme cold lasted but a few hours, still no ice formed in the flume. The water (a continuous flow of 350 cubic feet per minute) in the flume was drawn directly from the Spearfish River (supplied at the upper end by springs), which was at this season frozen over. The water did not freeze because the flume was well protected and set in close to the bank, thus allowing no circulation of air under the sills, the outer ends being covered with

Flumes. 147

snow ; the boxes were set to an exact grade and the curves were constructed carefully, so that along the en- tire line there was no splashing or slack water or irregu- lar currents ; and, furthermore, the water, coming from springs, was warm and the distance run was short.

The Wyoming and Dakota Water Company's main conduit from Spearfish was designed with the view of conveying water to the mining camps of Deadwood, Cen- tral, and Lead. The total length of the projected line to its main distributing point was thirty-five miles, consisting of twenty-six miles of flume (including a mile of tunnel and approaches) ; two and three-fourth miles of twenty- two-inch diameter wrought-iron pipe for inverted si- phons, crossing depressions from thirty-four feet to seven hundred and sixty-eight feet ; thirty-five hundred feet of trestle-work (the longest piece being three hundred and ninety feet long and seventy-five feet high), and the re- maining portion of the line was to have been ditched. The capacity of the conduit was estimated at 1,000 twenty- four-hour miner's inches. The principal supply was to have been drawn from a reservoir at the head of the Spearfish River, and additional amounts were to have been obtained from seven different tributaries or feeders along the line of work.

Owing to conflicting interests and litigation this ex- tensive work was never completed. The accompanying plan (Fig. 15) is a profile of the projected line, showing the grade, depressions, and work completed in 1879.

Details of Construction.— In constructing a line of flume, the bed being prepared, the stringers are put in place and the sills laid on them four feet apart. The bot- tom planks (the ends being sawed off square) are then nailed to the sills, the end joints being carefully fitted. The side planks are nailed to the bottom planks and to the posts, which last are set in a gain in the sills, an occa- sional cap in the beginning being placed on the posts to hold the flume in shape. The size of the nails for planks.

148 Flumes.

posts, and caps depends on the thickness of the material, six teen-penny and twenty -penny nails being those gene- rally used. The battens are securely fastened over the various joints or seams with six-penny nails. Each box as completed is carefully set on the established grade and firmly held in position with wooden wedges. The remain- ing caps are put on whenever convenient.

Where a flume connects with a ditch the posts for. a distance of several boxes back are lengthened sufficiently to permit of the introduction of an additional plank on each side. The end boxes of the flume are flared, to per- mit a free entrance and discharge of the water. An outer siding, nailed to the posts, at the junction with a ditch, or wherever else a bank of earth is passed through, protects the flume and also strengthens it materially.

When large amounts of lumber are to be used, it is oc- casionally economical for a company to erect a portable saw-mill and cut out the lumber. In most cases, how- ever, it is cheaper to contract for the material required.

All lumber should be inspected and measured by a competent scaler, whose duty it is to reject all knotty, sap, wind-shaken stuff, and slabs. As only dimension stuff is used, everything should be prepared at the mills of the exact sizes required, so that the flume can be constructed as rapidly as the material is received.

The material should be delivered at the head of the flume, or at such convenient places as the engineer may direct. Lumber stored should be carefully piled, and spaced so as to permit a free circulation of air through the material.

Sufficient water is generally obtained along the line of work, and is turned into the flume as fast as constructed, to assist in the delivery of the lumber which is floated. A few inches* depth of water is all that is necessary. One or two or more men are required to attend to the floating of the material, according to the distance.

As occasion may demand, the flume is trestled, the

Flumes. 149

main supports being placed every eight to twelve feet. The lumber, scantling, and struts for bents are used in accordance with the demands of the work. The founda- tions must be made secure to hold the superstructure, and no mortises used, heavy spikes and strong timber and braces being sufficient. Guy ropes are employed when necessary to prevent any vibration or movement of the flume caused by severe wind storms.

It is the usual practice to distribute along the line of a ditch and flume a certain amount of lumber, to be ready, in case of accident, for repairing any breaks. Breaks on ditch lines, especially during the winter, are repaired more easily with pieces of flume than with dirt. A supply of ten per cent, of lumber is not an excessive amount to have on hand. The life of a flume, under the best of circumstances and care, will not exceed twenty years, and generally not over half that time.

Lumber. — The following tables show the amount of lumber required in the construction of twelve-foot flume- boxes of different widths and depths :

TABLE IX. Flume two and one-half feet wide, two and one-half feet deep; twelve-foot box.

3 Caps, 4feetlongX 3 inches X 4 inches 12 feet b.m.

9 Planks, 12 - " X iH " x] !!

3 Sills. " X 4 '' X 4 " ...

I Foot plank, 12 Xio " X i) "

=135

18

48

18

15

Total lumber in one box 264 feet b.m.

Number of boxes per mile 440

Iso Flumes.

TABLE X. Flume four feet wide three feet deep; twelve-foot box.

Planks, 2 inches thick, 12 feet long =240 feet b.m.

6 Posts, 4 inches X 5 inches X 3 feet 9 inches long.. =38

Total lumber in one box 549 feet b.m.

TABLE XL Flume seven feet wide four feet deep; twelve- foot box.

Planks, inches thick, 12 feet long =270 feet b.m.

6 Posts, 4 inches X 6 inches X 4 feet 4 inches long. 52

Total lumber in one box. 689 feet b.m.

Bracket Flume. — A novel method of carrying flumes along the face of precipitous cliffs has been de- signed by W. H. Bellows and adopted on the line of the Miocene Mining Company's ditch in Butte County, to avoid the construction of a trestle-work one hundred and eighty-six feet high.

The line of ditch was run some two hundred yards up the cafion, abutting against a perpendicular wall of ba- saltic rock, along the face of which, one hundred and eighteen feet above the bed of the ravine and two hun- dred and thirty-two feet below the top of the cliff, the flume was carried on brackets for a distance of four hun- dred and eighty-six feet. Fig. 16 gives a general view, and Fig. 17 shows the method of hanging the flume.

The brackets are made of T-rails of thirty-pound rail- road iron bent into the form of an L. The longer arm,

Flumes.

Isi

O 1J

O

o

n

CO c,

H

-5

w

n

o

Flumes.

Ui

u

O

U

o

fx.

u]

Flumes. 153

ten feet long, is placed horizontally (for the bed of the flume to rest on), with its end supported in a hole drilled in the rock. The shorter arm, two feet long, stands vertically and has at its upper end an eye into which hooks a suspender of three-fourth-inch round iron, which in turn is fastened above to the rock by means of a ring- bolt soldered into a hole drilled for the purpose. The brackets are set eight feet apart, and were tested to sus- tain a weight of fourteen and one-half tons. The flume is four feet wide and three feet deep, inside measurements, and has a capacity of 3,000 miner's inches.

The general view shows a trestle eighty-six feet high. Along the line of the ditch there is a trestle one thousand and eighty-eight feet long and eighty feet high ; another has been built one hundred and thirty-six feet high. The total length of ditch and flume is thirty-three and one- third miles.

Details and Costs of Milton Ditch and Flumes. — The following official statement shows the details and cost of construction of the Milton ditch and flumes from Eureka to Milton Dam.

Built by the North Bloomfield Gold-Mining Company in the years of 1872-3-4.

Lengths.

Eureka to South Fork 563 chains= 7.04 miles.

South Fork to Drop-off. 96 =1.20 "

Drop-off to Milton 894 " =11.17

Total 1,553 chains=i9.4i miles,

102,484 feet,

measured from head of Eureka drop-off to Milton dam. Flumes.

Eureka to South Fork 961 twelve-foot boxes=say, 11,536 feet.

South Fork to Big Bluffs 264 3i68 "

Big Bluffs to Milton 1,113 t3352

Total 2.338 twelve-foot boxes=say, 28,056 feet.

The above 2,338 boxes include 56 boxes of flume built in the ditch, most of which is supported by heavy cribbing.

Flumes.

Waste-Ways.

Eureka to South Fork 14 wastes, aggregating 113 feet.

South Fork to I5ig Bluffs 12 48 "

Big Bluffs to Milton 24 114

Total 50 wastes, aggregating 274 feet.

There are also several branch flumes, one large crossing flume, and about one hundred and thirty feet of ditch lining.

Table Xil

Cost of Milton Ditch, from Mil ton to Eureka 19.41 miles*

Excavation, etc*

Ditch

Dis- tance.

Labor.

Explo- sives.

Tools.

Steel.

Coal.

Totals.

Miles.

$69,664 92

$4,098 46 a.866 72

$1,606 67

$319 48 ca 18

$76,642 91

18,919 73 3,67a oi

Flume Foun- dation

Clearing Line..

30X I J

$88,260 33

$6,965 18

$2,222 17

$532 48 $1,254 49

$99234 65

Flume, Lumber, etc., Milton to Feet.

lower end Big Bluffs . . 1,083,434 Less sold to Milton Feet.

Coinpany 200,000 883,434

Eureka to Big Bluffs, 1,225 boxes 765,911

Total on hand and used for 2,338

boxes 1,649,345 $32,015 28

Note, — Of the above amount of 883,434

feet it is supposed that there is on hand,

say, 130,000 feet, thus leaving 750,000

feet as the amount used for 1,113 boxes

from Milton to lower end of tlie bluffs. Timbers cut by hand, stringers, posts, etc. 1,301 49 Hauling timber to Milton, Little Poor

Man's, etc 1,650 00

$34.966 77

Carry forward $134,201 42

Flumes.

TABLE Xlh— continued. Brought forward $134,201 42

Carpenters etc.

Gang.

Boxes 13 ft. long.

Labor.

Naib and Iron.

Tools.

Totals.

♦24,559 85

Young

Marriott

M45

$io,9oa 81 10,497 90

$'.499 57 1,559 57

$5000

$12,452 38

12,107 47

2,338

$21,400 71

$3-059

$100 00

$24,559 85

General Cost. Surveys. — Engineer (who was also fore- man) and assistants $4,610 50

Roads, — South Fork to Bow- man's, 3J miles $1,200 00

South Fork to Little Poor

Man's, 2] miles 200 00

1,400 00

Hauling, — Transportation of tools, mate- rial, and men 1,450 94

Boarding. — Loss in boarding laborers, who

were charged 75 cents per day 685 75

General Expense. — Being a portion of North Bloomfield Gravel - Mining Company's cost of management, office, taxes, etc., while ditch was being built 3*564 63

11,711 82

Damages. Eureka Lake Company — damage to it by breaking its

miner's ditch by blasts 1,635

Total cost $172,108 96

Collected from Milton Company for account extra

work 689 30

Leaving Milton Ditch account (November 10, 1874) on Company's books $171,419

Flumes.

Note, — If the 130,000 feet of lumber supposed to be at Milton is sold for cost ($20 per thousand), the total cost of the ditch will be reduced to $169,508 96, or, say, $8,700 per mile. In that event —

Cost per foot etc. Ditch. — 74,442 feet long, cost for, say, 117,600 cubic yards,

$76,642 91, or 65 cents per cubic yard, or $1 03 per lin. foot. Flume. — 28,056 feet long, cost for excavation '

$18,919 73, or 67 cents per lin. foot

cost for lumber, labor, etc., $59,526 62, or $212 per im. foot

The ditch is graded in from slope pegs from 6 to 36

'$2 79 per lin. foot.

Jtpxte of sccurln-ff tijtume on thfMQunUiin side.

Fig. 18. Milton Flume.

inches. The general grade is 19.2 feet per mile. All trees within 15 to 25 feet of the edge of the upper bank are cut.

Flumes. 157

The logs, brush, and leaves from the lower bank (under the artificial bank) are carefully removed. The founda- tion is generally cut for the entire width of the flume. The sketch (Fig. 18) shows the method of posting along cliffs, where the foundation is occasionally narrower than the flume. Where flumes connect with the ditch, the posts of the flumes, for a distance of several boxes, are 4 to 4j4 feet high, allowing an additional side plank. The grade of the flume is 32 feet per mile. The planking is 2 inches thick.

Chapter Xi.

Pipes And Nozzles.

Wrought-Iron Pipes. — Wrought-iron pipe is used extensively in California on account of its cheapness of construction, its adaptability for crossing depressions, the facility with which it can be moved (changes of the posi- tion of the line being often necessary), and other advan- tages arising Irom its lightness combined with great ten- sile strength.

It is used as —

(i) A water-conduit, replacing ditches and flumes. Where large depressions are crossed it is called an " in- verted siphon."

(2) A "supply or feed pipe,** conveying water from the " pressure box to the claim.

(3) A " distributing pipe,** taking the water from the "distributer,** or "gates,** at the end of the supply pipe, and delivering it to

(4) the " discharge pipe or " nozzle.**

Large mining companies often have their pipes con- structed at their own workshops, although generally the iron plates of proper size and thickness are punched and rolled before delivery, and put together on the claim.

Inverted Siphons. — According to Father Secchi, there is near the town of Alatri, in Italy, an " inverted siphon with a depression of three hundred and thirty- eight feet, supposed to have been constructed by the Romans two hundred years before Christ. The pipes

Pipes And Nozzles.

are of earthenware, embedded in concrete, and are said to be still in a good state of preservation. There is, there- fore, no novelty in the construction of this kind of water- conduit ; but the use of wrought-iron pipe for this pur- pose was very limited until adopted in California, where it has been very largely employed, and where there have been obtained valuable data of the strength of materials and methods of construction, as well as of the flow of water through long pipes, essentially modifying theories and formulas previously accepted.

Thickness of Iron. — The thickness of the iron is determined by the pressure of the water and the diame- ter of the pipe, allowance being made, of course, for the quality of the material and the method of riveting. The factor of safety against damage from accident is regu- lated by the importance of the line. On account of va- riations in plates marked as being of the same size and number, it would be well, as a precautionary measure, to

Table Xiv.

Thickmss and Weight of the Principal Sites of Iron used for Hydraulic

Pipe.

No. B.G,

Thickncss.-Inchet.

Weight per sq. ft.— Pounds.

No. B.G.

Thickneu.— Inches.

Weight per q. ft.— Pounds.

A +=.065

i+=.259

i-=.I20

A- =.300

1 + =.380

A-=.i8o

l6o riPES AND NOZZLES.

weigh each plate used, as thereby any essential difference in thickness could be detected. Iron plates which have been subjected to the action of salt water are undesirable.

The Spring Valley Water Company, of San Francisco, California, strain their pipes from 11,400 to 13,000 lbs. per sectional inch.

The Virginia City and Gold Hill Water Company, of Nevada, has an inverted siphon (of inferior English iron) with a maximum pressure of 1.720 feet head, equal to 746 lbs. per square inch, No. o iron, with -inch rivets, being used at the lowest point of depression and sub- jected to a tensile strain of 13,310 lbs. The No. 9 iron is strained fully 15,000 lbs., and the No. 7 over 14,000 lbs., per sectional inch.

The Texas Creek pipe, four miles below the Bow- man Dam, Nevada County, California, is an inverted siphon 4,438.7 feet long, 17 inches in diameter, made of riveted plate iron. Its inlet is 303 feet above the outlet, and with a full head it will discharge about 1,260 miner's inches. It sustains a maximum pressure of 770 feet or 334 lbs. per square inch.*

At Cherokee,t California, there is an inverted siphon of ordinary English plate, 30 inches in diameter, with a maximum pressure of 887 feet head.

The maximum strains on the several sizes of iron used in practice are given in the following tables :

See Official Report North Bloomfield Mining Co., 1878. t For further description see p. 173.

Pipes And Nozzles.

M 00

?

Diameter.

?

M M M p p

lid

? ? ? 5 s.*

M H H

8. -a S 5 s

r

P

M M M

M

.- r p p p

vt ui en

3 M

Mmmmmmmmiom

3 a

Cd .

§

y. ?

w

r

sr

Mmmmmmmmmmmmmmmm.

2a:

5?

pa:

?9

MMMMt-ii-iiMi-ii-iM

en w M OO b oo r

if If

;g: S: a:

r : 9 . r . . P' . S

1?

5:

8: s: 3:

S: t::g: 3-. s

00

M

M

00. "vl . o.

; p; ; M ; 00; g

1?

:?

w

Pipes And Nozzles.

Riveting. — For ordinary pipe under light pressure a very common style is to have the seams single-riveted, the rivets (say of an inch in diameter for an i i-inch pipe) being spaced i or inch apart on the longitudinal seams, and sometimes as much as 3 inches apart on the circular seams. Pipe thus put together becomes water- tight in use through the particles which naturally float in the water, or can be made so by throwing in a few bags of sawdust or shovelfuls of dirt, and will remain tight even when subjected to a pressure as great as 200 lbs. per square inch.

For heavy pressures and more careful construction the circular seams have a single row of rivets i inch apart while the longitudinal seams are double-riveted, with rivets spaced i inch apart in two rows about J4 inch from each other.

Cold-riveting is common. In yery particular work only is hot-riveting resorted to.

Table Xvil

Sixes of Rivets used in General Practice,

No. 18 and 16 iron, No. 10.9 and 8 iron, %y %

12 and II

i%y.%

HxiH

TABLE XVIII. Dttttils of Riveting a Vi-imh Pipe of the Spring Valley Water Co.

U

H§

l-sj

"0

.2*C

us

5"

l.sl:§

No. 13

A in.

H in.

I in.

iH in.

%in.

H

A "

fi "

I "

iH "

H "

" 9

H "

"

ift "

full lA "

H "

A in.

H "

iH "

" iH "

A"

M "

H "

H "

lA "

" iH "

Pipes And Nozzles.

Joints. — The pipes in general use in the mines are II, IS, 22, 30, and 40 inches in diameter, of riveted sheet iron Nos. 8, 10, 12, 14, or 16 (Birmingham gauge) made in sections of 30 to 36 inches, riveted into lengths of about 20 to 30 feet, which latter are very frequently put to- gether in stove-pipe fashion, neither rivets, wire, nor other contrivance being necessary to hold the joints in place. This stove-pipe connection is sufficient in ordinary cases. When it will not suffice iron collars and lead joints are used.

The annexed sketch (Fig. 20) shows the style of joint

Fig. 20. Lead Joint.

originally used on the siphon of the Virginia City and Gold Hill Water Company.

The cut shows the joint which is made between every two lengths of pipe, or 26 feet 2 inches : a is a. wrought- iron collar, 5 inches wide, of an inch thicker than the iron of the pipe, and with a play of of an inch between the inside of the collar and the outside of the pipe ; d is the lead, which is run in and then calked tight from both sides ; r is a nipple of No. 9 iron, 6 inches in width, rivet- ed on one end of each pipe by means of six -inch rivets.

Pipes And Nozzles.

Fig. 21 shows the method of tightening leaky joints: a shows the clamp and its application for forcing back the lead which has worked out through the expansion and

contraction of the pipe. This is shown both in perspec- tive and in cross section. The clamp b is used to keep the lead in place after it has been forced back by the

Pipes And Nozzles.

clamp a. The two lower sketches of this clamp b show both the side view and the elevation.

Fig. 22 shows the elbow used in making short curves. a a are angle irons riveted on the pipe on the outside of the curves, and, by means of iron straps, connected

Pipes And Nozzles.

with the corresponding angle irons on the next pipe, as

denoted in Fig. 23, which shows the manner in which the pipes and elbows were strapped together when- ever the curve was suffi- ciently short to require this precaution against an out- ward movement.

Air - Valves, Blow- offs. — On a long line of pipe, or a siphon, " blow- offs " and air-valves are pro- vided to allow the escape of the air from the pipe while filling, and especially to prevent a collapse of the pipe in case of a break. The valves in use are of varied make. A simple construction is a piece of leather loaded on the inside of the pipe, and arranged to cover an opening from i inch to 4 inches in diameter. A bet-

FiG. 24. Air-Valve for 22' Water-

PlPES.

Fio. 25.

ter class of valve is shown in Fig. 24,

Pipes And Nozzles.

This sinks and opens when the water leaves it, and floats and shuts when the water rises to it.

The contrivances used on the Virginia City and Gold Hill Water Company's siphon are shown in Figs. 25 and 26.

Fig. 25 shows the blow-off used in every low place (also marked with a triangle in the profile, Fig. 27).

Fig. 26 shows the self-acting air or vacuum valve used at each high point on the line. When the water is on, the valve a is kept open and the valve c closed, while the self-acting valve b is shut by the pressure. If any air ac- cumulates in the pipe it is blown off occasionally by opening the cock, c. Should a break occur in the main pipe-line at a point lower than the air-cock, and within its district, the valve b falls down and admits the air so as to prevent a vacuum. After a break on the main line is repaired and the water is let on again, the valve b being down or open, the air rushes out, the valve-stem being weighted, d, so as to close only when the water reaches it.

Preservation against Rust and Accidents. — In order to protect the pipe it should (as far as possible) be laid in a trench and covered with earth to a depth of at least one foot for the ordinary conditions of hydrau- lic mining.

Wrought-iron pipes should be treated externally and internally with asphaltum or coal-tar, the life of a pipe being dependent to a very great extent upon this bitu- minous coating, which preserves the iron from rust and

Fig. a6. Self-acting Air-Valve.

l68 PIPES AND NOZZLES.

the corroding action of water. Thin iron pipes well coat- ed are still in good condition after fifteen years of ser- vice.

The following preparations have been found valuable in practice :

Crude asphaltum 28 per cent.

Coal-tar (free from oily substances) 72

Or

Refined asphaltum i(i% per cent.

Coal-tar (free from oily substances) 833

The (Santa Barbara) asphaltum, in small pieces, and the coal-tar are heated to about 400 degrees Fahr. and well stirred. The pipe is thoroughly dried and immersed in the mixture, where it remains until it acquires the same temperature as the mixture. When coated it is removed, placed on a trestle to drip and dry in the sun and air. For convenience of immersion wrought-iron troughs, some 30 feet long, 3 feet wide, and 2 feet deep, are used. No. 14 iron requires immersion for about 7 minutes, and No. 6 for 12 to 15 minutes.

Filling Pipes. — A pipe-line being finished, water must be admitted in such a way as to prevent the air from being sucked in, which will happen (and to a great extent) unless care is taken. The best plan is to put a gate in the pipe below the level where the water enters, and thus regulate the flow, maintaining a steady pres- sure and avoiding violent oscillations. The common plan of admitting the water through a pen-stock, which is kept filled so that the water is quiet, will answer if proper care is exercised.

Statistics Of Pipe-Lines.

La Grange Hydraulic Mining Company.— The

following are the details of the cost and construction of I,233j4 feet of 22-inch wrought-iron pipe made at the works of the La Grange Hydraulic Mining Company, Stanislaus County, California.

The iron used was No. 16, U. S. wire gauge, or 0.05

Pipes And Nozzles. 1 69

inch thick. The pipe sections averaged 19 feet in length, containing each 8 sheets of iron 6 by 3 feet. The laps were inches at the joints and single-riveted, the rivets being driven inches from centre to centre in -inch- diameter holes. To each sheet of iron 77 rivets were used, 28 on the longitudinal and 49 on the circular seams. The heads of the rivets were inch in diameter by inch thick, and the shanks % inch in diameter by 0.44 inch long. The rivets weighed about ounce each, or 128 to the pound.

Cost Of Onr Running Foot Of Pipe.

Iron 57 6 sq. ft., or 11.82 lbs., at 4 cts $0 53

Rivets, 32, or 0.25 lb., at 13 cts o 03

Punching and rolling o 12

Freight on iron and rivets, at i ct. per lb o 12

Labor contract per foot o 25

Tarring o 03

Total cost per running foot $1 08

Table Xix.

North Bloomfield.— Cost of iron pipe at North Bloomfield, 22 inches diameter. No. 10 iron, double-riveted, per length of 17 feet 3 inches:

Six sheets iron 36' X 72', No. 10 540 lbs., at 4.38 cts $23 65

Freight, Sacramento to Bloomfield, 80 432

Labor by contract, 17' 3', 25 "per ft.. 431

Wear and tear of tools, 3 cts. per foot; tarring, 3 103

Total cost of 17' length $34 51

or $2 per lineal foot.

B. Cost of iron pipe 22 inches diameter. No. 12 iron, double-riveted, per length of 17 feet 3 inches:

Six sheets No. 12 iron, 36' X 72' 480 lbs., at 4.38 cts $21 02

Freight, Sacramento to North Bloomfield, "80 384

Rivets, A' Xi' 10 lbs, "10 i 00

Labor, 21 per ft.. 3 62

Wear and tear of tools, and tarring, 6 i 03

Total cost of 17' 3' length $30 51

or $1 77 per lineal foot.

170 Pipes And Nozzles.

The above pipe was double- riveted on the longitudi- nal seams, and single-riveted on the circular seams. The long-seam rivets were spaced ij inches; the rows were I inch apart. The circular-seam rivets were spaced inches apart. The sheets of iron were not cut, but punched so as to make a pipe full 22 inches diameter.

The No. 10 iron is used under 450 feet head, with noz- zles as small as six inches in diameter. The No. 12 iron is used under 410 foot head, with nozzle as small as 7% inches in diameter.

The cost of an outfit of tools for large-pipe making (iron up to No. 10, B. G.) is as follows :

Rollers $150 00

Stake 50 00

Punch 100 00

Hammer and tools 25 00

Fitting up, etc 75 00

Total $400 00

Spring Valley Water Company, San Francisco.

— The following figures, given in tabular form, show the details of the construction of an 18-inch wrought-iron pipe, 5,800 feet long, made for the Spring Valley Water Company, which supplies the city of San Francisco. This pipe has a tensile strain of about 5,000 or 6,000 lbs. per sectional 'inch, and was made with this low co- efficient in order to withstand the pulsations caused by a single-acting plunger pump making as high as 36 (four-foot) strokes per minute. These pulsations in prac- tice vary from 5 to 9 lbs. per stroke when the air-vessel is properly charged, but through carelessness they may exceed 50 pounds.

Details by Joseph M oore Supeiinteiuleiit of the Risdon Iron-Works, San Frandsco.

Pipes And Nozzles.

is;

bT

Thickness of the bonds.

M

A

Width of the bands.

Thickness of the sleeves.

£

Cm

Width of the sleeves.

%

t

t

t

t

t

t

t

Width of the sheets used in the pipes.

W

u

m

M M

?1

i:

P

Thickness of the iron used in the pipes.

"1

a:

i;

P

Diameter of rivets used.

M

Pitch of the circle seanu in the outside courses.

Ok

Pitch of the drde seams in the inside courses.

r

Cn

M

w

M

P

Amount of two laps.

s

k

k

M

M

Space between double row.

is S

S3

S5

in

N

M

t

S

a

Length to the joining holes in the ouuide courses.

is

%

M

a

a

Length to the joining holes in the inside courses.

? s

Whole length of the outside courses.

s

!

Whole length of the inside courses.

%

%

%

%

%

!g

pr

Spaces in the circle seams.

p

Pitch of the double row.

£

£

,2

s

s

s

Spaces in the double row.

p

Amount of the two outside spaces of the double row.

M

Amount of two laps for the double row.

w r w

172 Pipes And Nozzles.

Virginia City. Water-Works.— The Virginia and Gold Hill Water Company have an inverted siphon across the Washoe Valley, Nevada, 7 miles long, inches in diameter, of riveted wrought iron. The total weight of the siphon is about 700 tons. The pipes were hot-riveted, with a single row on the circular and a dou- ble row on the longitudinal seams, a million rivets being used. The separate lengths were united by lead joints, previously described (see p. 163). For these 35 tons of lead were required. The pipe was constructed in 1872 of inferior English iron, but is still (1883) in good con- dition. The No. 9 iron is strained fully 15,000 lbs., and the No. 7 over 14,000 lbs., per sectional inch. The pipe is said to have been tested to a pressure of 1,400 lbs. per square inch.

The annexed sketch (Fig. 27) shows the profile. The numbers along the line give the thickness of iron, B. G., used under the various pressures which are indicated in the perpendicular columns of figures from 100 to 1,700 (feet), at the points where the parallel lines strike the pro- file. The triangles below the line denote the locations of the blow-oflfs, and 0, above the line, represents the air- valves. These have been previously described (see pp. 166, 167).

Spring: Valley and Cherokee Hydraulic Mining Company. — At Cherokee, Butte County, California, the Spring Valley and Cherokee H. M. Company has an in- verted siphon of wrought iron, 30 inches in diameter, which discharges 53 cubic feet of water per second. This was the first large construction of the kind on the coast. It has been in continuous use for 12 years, and is still in good condition. The material was ordinary English plate. The greatest pressure is 887 feet.

The sketch (taken from the original survey) shows . the profile and the different sizes of iron used. The maxi-

♦ The Mining and Scitniijic Press of January 7, 1871, contains a detailed account of the construction of thispipe and a diagram of the line.

Pipes And .Nozzles.

PIPES AND NOZZI.es.

mum strains on each size are given in the following table:

Table Xxi.

Details of Spring Valley and Cherokee Pipe,

Size of Iron.

Greatest Pressure.

Maximum tensile

strain, in pounds

per sectional inch.

Birmingham Gauge.

Feet head.

Pounds per square inch.

No. 14

13,374

a 12

17,202

" Ii

15,875

17,240

15,080

15,420

I

15,360

Flow of Water through Pipes.— A series of ex- periments on the flow of water through circular pipes was made by Hamilton Smith, Jr., at the works of the North Bloomfield Mining Company and at New Alma- den, in Santa Clara County, California. The details of these experiments were communicated by him to the American Society of Civil Engineers.

The following table (XXII.), compiled by Mr. Smith, shows the results of 88 experiments as to the discharge of water through circular pipes varying from 4 feet to inch in diameter," and with velocities varying from 20 feet to of a foot per second. The standard of mea- sure used was that of the United States Coast Sur- vey. The temperature of the water in Nos. 35 to 87 was about 65° Fahr.; in the other experiments, from 50° to 55° Fahr.

f

h new gas-pipe, untarred, and funnel at mouth.

;i

7Q 8t

8a

8?

ch new gas-pipe, tarred, with funnel.

uh gas-pipe, with funnel ; pipe had been several years in use.

-inch new gas-pipe, no funneL

£;h glass pipe, with funnel.

fourths-inch glass pipe, no funneL

2lf- glass pipe, no funnel.

35

one-and-a-quarteT'inch pipe, no funnel, rcf ully tarred and comparatively new.

npwittHi

Pipes And Nozzles.

'75

o

o

z

Js.

H

s

S.S

Is,

,A .

q

ai

ifS

fi

a 2

nl

S

§

s-5

,.

W

-l

P

2*.

'i

pj?

n

Is

-r

?S

ff

%

,

og

P

ig

r

r

y

?2.

's

Si

ki:

,

s

tfs

is

?

N

F

"5

j

Q

€

Sz

i3 T]

s

§

'

J' 3

tl 1

n

rg

f

Ok

F

r

'

a

-K

'?!

5*-

§

i- CO

'

'

Tis

a O

?B

s

§

S

s

r

Z

?§

1/6 Pipes And Nozzles.

The experiments are all reduced to the formula :

(dk'Y

where v velocity in English feet per second.

d mean diameter. / length.

// effective head.

m variable coefficients. The effective head h' was derived from the total head h as follows, c being coefficient of contraction at en- trance :

The Pressure Box.

The pressure box is situated at the end of the ditch in a commanding position above the claim, and from it the water is delivered into the supply pipe. The box derives its name from the fact that the head or pressure is measured from this point. Connected with or forming a part of the pressure box is the sand box, which is sunk below the level of the flume or ditch, and arranged to catch the gravel or sand carried along by the current. It is emp- tied by a side gate as circumstances may require.

The pressure box is a large wooden receptacle, gene- rally constructed of i)-inch planks, and securely held together with timbers. It is sufficiently large and deep to keep the head of the pipe, which enters it, under water with a steady pressure.

A grating of bars is arranged to catch all floating ma- terial, such as sticks and leaves. The water should be quiet and sufficiently deep to prevent any air from being carried into the pipe. For this purpose the box is divided into compartments, one of which receives the water and

See Trans, of the Am. Society of Civil Engineers,'* vol. xii. No. 304, pp. lao-iaj.

Pipes And Nozzles. 1 77

quietly discharges it into the second through lateral open- ings. There should be no perceptible difference between the water-supply and the discharge, or, if any, the former should be in excess, and the surplus should be regulated and discharged by a waste-gate placed near the end of the flume. Some pressure boxes are arranged for two pipes.

La Granse Pressure Box.— The following is a de- scription of a pressure box at the La Grange Mine, Stan- islaus County :

Some 350 feet to the rear of the pressure box there is a sand box in the ditch connecting with the waste- way. This sand box is 2 feet deep (below the bottom of the ditch), 4 feet wide, and 4 feet 3 inches long, and com- municates with the waste-way by means of a gate which slides clear to the bottom of the box. At the pressure box the four end posts and the two caps belonging to them are made of 6x8' lumber. The six intermediate posts, three on a side, are of 6x6' material, and their caps are of the same dimensions. All the sills, and the two longitudinal stringers on which they rest, are of "stuff." Up to high-water mark the box has a double lining made of two i>-inch planks battened at the joints with strips inch by 4 inches. A 22-inch pipe takes the water. Nine feet from the box there is a 5-inch diameter stand pipe which extends 2 feet above the top of the pres- sure box.

In large claims the pressure box ranges from 10 to 20 feet in length with a single pipe, and, where two pipes are used, from 12 to 30 feet. Larger boxes are also built where the pressure, sand, and measuring boxes are com- bined in one.

The pressure box at the Bloomfield Mine is 18 feet long and 6 feet wide, so arranged that the sand falls under a wooden diaphragm into a large chamber pro- vided with a gate.

178 Pipes And Nozzles.

The Supply Or Feed Pipes.

The water is conveyed in iron feed pipes from the pressure box to the claim, and by means of iron gates on the lower end of the feed pipes it is distributed to the discharge pipes. The supply pipe is funnel-shaped where it connects with the pressure box, and from there on it is usually of uniform diameter as far as the gate or discharge nozzle.

Where 22 to 30-inch pipes are used it is not advisable to use lighter iron than No. 14, B. G., even under ex- tremely low heads, as lighter pipe of that size will not bear handling.

The main supply pipe should descend in the most con- venient and direct line into the diggings, avoiding, so far as practicable, angles, rises, and depressions. Air-valves should be arranged at proper distances to allow the es- cape of air when filling the pipe, and also to prevent any collapse. Where the pipe passes over steep banks into the claim it is carried on a trestle and braced, care being taken to prevent any movement of the column. When necessary the pipe is secured with frame-work and weighted with stones. At all angles the pipe is braced and weighted.

In filling the supply pipe the water should be turned on gradually, all sudden straining of the column being thus avoided. Leakage in the slip joints can be readily stopped with a few bags of sawdust or by wedging them with thin pieces of soft pine. Large leaks have to be closed by iron grip-bands drawn together by means of screws or wedges.

The lower end of the supply pipe was formerly fitted into a distributing box of cast iron, from which one or more branch pipes were taken by means of gates. These are now abandoned owing to their great cost and liability to burst.

The present practice is to fork the main pipe wherever

Pipes And Nozzles.

an attachment is required, cast-iron gates being placed on each branch. The annexed sketch (Fig. 32) shows the form of these gates used in the mines, and also as a dis- charge gate for reservoirs.

Where several branch pipes are supplied from the same main pipe they are usually of smaller diameter.

Fig. 32. Distributing Gate.

Their use arises from the greater convenience of moving the smaller pipes. They are generally 11 and 15 inches in diameter. It is recommended, however, in order to prevent a loss of head, to continue the branch pipes of the same size as the feed pipe, and to regulate the dis- charge by the size of the nozzles. At the Southern Cross and Polar Star Mines the supply pipes at the pressure box are 40 inches and 48 inches (respectively) in diameter, tapering for 500 feet to 22 inches, which size they retain for 2,800 feel, then branching into two pipes each of 15 inches. At the Malakofl the pipe at the head is 27 inches, narrow-

l8o PIPES AND NOZZLES.

ing to 22 inches and 15 inches for the branches. At this mine nozzles of 6 inches to 9 inches diameter are used under a head of 450 feet. At the American Mine the pipes are 34, 22, and 1 5 inches. At the Bonanza Mine all the pipes are 16 inches. At the Milton Company's Manzanita Mine the pipe is 22 inches from the pressure box to the nozzles. This pipe is 4,000 feet long, with a head of 430 feet.

The Discharge Pipe Or Nozzle.

Goose Neck. — The first improvement in discharge pipes was a flexible iron joint formed by two elbows, one working over the other, with a coupling joint between them. These elbows were called Goose Necks.

Fig. 33.

Their construction was very defective. The pressure of the water caused the joint to move hard, and when the pipe was turned horizontally it was apt to "buck," or fly around in a contrary direction. The same thing occurred in elevating and depressing the pipe.

Globe Monitor. — The Goose Neck was succeeded by the Craig Globe Monitor, a simple ball-and-socket joint, which was difficult to work, often requiring several men to manipulate it.

A subsequent invention of Mr. Craig was the interior tripod and belt. This was a tripod with a centre hav- ing a hole to take a bolt with a knob on the end ; the other end passed out through the top of the elbow and had a nut with a lever. By tightening the nut it threw

Pipes And Nozzles.

the strain on the bolt and reduced the friction on the joint proper/* These machines were hard to manage and soon became leaky at the joint.

Fig. 34. Craig's Globe Monitor.

Hydraulic Chief. — The invention of Mr. Craig was succeeded by the " Hydraulic Chief," sometimes known as the Knuckle-joint and Nozzle,*' invented by Mr. F. H. Fisher. The main features consist of two elbows placed

Fig. 35. The Hydraiiic Chief.

in reversed position when in right line, connected by :i ring in which there are anti-friction rolls. The ring is bolted to a flange on the elbow, but gives the upper elbow a free horizontal movement, while the vertical mo- tion is obtained through the knuckle-joint, which is placed

1 82 Pipes And Nozzles.

in the outlet on the top elbow. This joint is simply a concave surface fitted to a convex one, the former having an opening for the pipe to pass through.

The interior of the machine is unobstructed by any bolts or fastenings, and the man at the pipe can operate it by means of the lever without personal danger. Vanes, or rifles, are inserted in the discharge pipe to prevent the rotary movement of the water caused by the elbows, and to force it to issue in a straight line, concentrated and in a solid form. These machines soon become leaky and are expensive to keep in drder.

Dictator. — In 1870 the Hoskins Dictator was patent- ed. This was a one-jointed machine, having an elastic packing in the joint instead of two metallic faces. The joint worked up and down on the pivots, and in rotating it the wheels ran around up against the flange. This ma- chine, though simple, is but little used.

Little Giant. — Mr. Hoskins subsequently invented

Fig. 36. The Little Giant.

the " Little Giant," a two-jointed machine, which, on ac- count of its simplicity and durability, rapidly superseded all others. It is portable and easily handled, having a knuckle-joint and lateral movement. The Giants have rifles, and nozzles from 4 to 9 inches in diameter, 5>i to 7-inch nozzles being most generally used.

Pipes And Nozzles. 1 83

In setting Giants they must be firmly bolted to a heavy piece of timber, and this timber securely braced against the solid gravel or rock. The machine and adjacent length of pipe must also be weighted to the ground. The bearings should be lubricated. Tallow or axle-grease is preferable to oil for this purpose.

Hydraulic Giant.— The Hydraulic Giant is a modi- fication of the Little Giant. The several sizes, as con- structed by Joshua Hendy, are as follows :

Inlet, Outlet, Inside Diana. Weight,

No. inches. inches. Nozzle Butt. lbs.

1 7 54 4 Jn. 245

2. 9 7 5 " 450

3.' II 7i 5or6'* 665

4 II 9t 7" 750

5 15 9i 875

Fig. 38. The Hydraulic Giant.

Monitor. — Fig. 39 represents a Monitor Hydraulic Machine with a deflecting nozzle,** the invention of Mr. Henry C. Perkins.

Deflector. — By means of the " deflecting nozzle the Giant can be turned to any point and the stream directed with the greatest facility.

Ay Cast-iron nozzle.

By Deflecting nozzle of wrought iron, attached to A by a joint similar to a compass gimbal.

Pipes And Nozzles.

C, Lever to govern the movement of B.

D, Rest for lever B,

The operation is as follows : When the lever, C, is in the rest, Dy the deflecting nozzle, B, being of a larger diameter than nozzle, A, allows the stream of water from nozzle, A, to pass through without obstruction. To move the pipe the lever is taken from the rest and thrust in the direction in which it is desired to throw the stream. Any move- ment of the lever, C, either to the right or left, or up or

Fig. 39. Monitor Hydraulic Machine.

down, throws the end of the nozzle, into the stream of water. The force of the water striking B changes the course of the discharge, the entire machine moving in ac- cordance with each change of the deflector.

Hoskins* deflecting nozzle is of cast iron, of the same size as the main nozzle, to which it is attached by a packed universal joint. This deflector is operated by a lever in a manner similar to that already described. It has the disadvantage of causing a constant interference with the stream of water, and is somewhat dangerous to use.

Chapter Xii. Various Mechanical Appliances.

Derricks. — Strong derricks are used in hydraulic mines to facilitate the removal of large boulders and rocks, which are of frequent occurrence. The present style of bed-rock derrick has a mast lOO feet high, and a boom 92 feet long, which is set in a cast-iron box placed on sills. The mast is held in position by six guys of galvanized iron wire rope one inch in diameter. A whip block, with three-quarter inch diameter steel rope, is used for the hoisting tackle. A twelve-feet diameter Hurdy-gurdy wheel is attached, and, using 30 inches of water under 275 feet head, it lifts stones weighing eleven tons. The guys are held by double capstans.

This derrick can be readily moved 100 feet in ten hours without being taken down.

Hurdy-gurdy Wheels. — Derricks and electric- light machines necessitate the employment of a motor, par- ticularly one driven by water, and capable of utilizing high heads. Hence the use of water-wheels of the class known as "Impact* Wheels," locally called Hurdy- gurdys.'*

These are wheels moved by a stream or jet of water issuing under pressure from a conical nozzle and striking open buckets on the circumference of the wheel. The buckets, originally flat, have been modified in shape, and thereby the efficiency of the wheel greatly increased.

Experiments at North Bloomfleld. — The first

See comment on the use of this term, p. 194. i8s

Various Mechanical Appliances.

Ground Pun

®

rT

\i/

®

Fig. 40. IIuRDY-GuKOY Wheel and Derrick-Hoist.

Various Mechanical Appliances.

Various Mechanical Appliances.

noteworthy experiments recorded were made about ten years ago by Hamilton Smith, Jr., at North Bloom- field. The wheel was of the ordinary pattern with flat buckets, 1 8 feet in diameter on the outside and 17 feet 4 inches in diameter to inner line of buckets (17 feet

Fig. 42. HuRDY-Gu&DY .

8 inches in diameter at centre line of buckets). The buckets were 4 inches deep, with flanges on each side. The work done was measured by a Prony dynamometer. The following table shows the result obtained. The head given shows the real head in feet at the point of the discharge.

Various Mechanical Applianxes. Table Xxiii.

Dtwription of aoule.

Nonleupered

Wmi

Nonlc tapered

Ring

Nonle

Nonle tapered, uncut,

Nonle

Noislecutoff

.s

g

3aa-3

axa.i

Stx

3i9.a

x.xxo

(3ia.6

(335-9

h

C/3

X4S.8

jl

Sua S

a-7

.,96

8-a,

c/3

66,1

5A

190 Various Mechanical Appliances.

Experiments at the Empire Mill.— An experi- ment at the Empire Mill, French Corral, was made under the following circumstances, giving the annexed results: Ten stamps, weight of each 693 pounds. Drop, 0.768 feet. Speed oi stamps, 62.2 drops per min- ute. Work done by 91.68 cubic feet of water per min- ute head, 130.1 feet. Size of wheel, 131 feet outer diameter. Diameter of wheel, 12.58 feet to centres of buckets. Size of buckets, 4 inches wide and 6 inches deep, set 10 inches apart. Water conducted to wheel through an 11 -inch pipe 866 feet long. The wheel was direct on the cam shaft; single cams used. The mill crushed 60 tons of gravel in 24 hours ; one-quarter-inch screens were used.

Description of nozzle Ring.

Diameter of nozzle in feel 182

Head, in feet, at nozzle 130. i

Discharge of water per second in cubic feet 1.528

Velocity of water due to gravity 91.4

Actual velocity of water at small diameter of nozzle 58.5

Speed of wheel at centre of buckets when running light

Highest horse-power developed lo.o

Ratio of work done to theoretical power of water 445

Speed of wheel at centre of buckets when giving most

work 41.0

Number of nozzle (sec sketch) 8.

The head at French Corral was the height of the water in pen-stock above the nozzle, no allowance being made (as in the North Bloomfield experiments) for the loss of head by friction in pipes and by leakage.*

Curved Buckets. — Recent patterns of wheels with curved buckets have given an efficiency very much in ex- cess of that described above.

Tests at the Idaho Mine. — A series of comparative tests was made in the spring of 1883 the Idaho Mine,

All the data given on pages 189 and 190 concerning Hurdy-gurdy wheels were com- municated by the author to the American Institute of Mining Engineers in a paper read at the Wilkesbarre meeting, May, X877. See vol. vi. Trans. Amer. last. Mining £n- jjineers.'*

Various Mechanical Appliances. I9I

Grass Valley, with the Fredenburr, Pelton, Knight, and Taylor wheels, the results of which are given below. The tests were made in public, all owners of wheels having a right to compete. Prony's Friction Dynamometer was used, the brake acting on wheels 6 feet in diameter. The point of contact with the scale beam (57.3 inches) described a circumference of 30 feet. The supply main was 6,900 feet long, 22 inches in diameter, with a head of SS6}4 feet at nozzle. A pressure gauge placed a short distance back from the discharge nozzle (1.89 inches (?) in diameter) is said to have registered standing 165 pounds, and running 162 pounds. The water from the wheel was discharged into a flume 36 feet long, 36.5 inches wide, and 24 inches deep. There were three check-boards placed in the flume below where the water entered. The hook gauge, arranged on one side of the flume, was set 24 inches back from the weir. The water passed freely around the hook and was very quiet in the flume. A weir, 12 inches deep and inches wide, made of yi- inch iron, over which the water flowed without contrac- tions, was placed at the end of the flume. Francis* for- mula for the discharge of water over weirs was adopted as the basis of the calculations.

The following are the official returns :

Fredenburr

Wheel.

Weight on brakes, lbs.

Revolu- tions.

Horse- power.

Head of

water over weir,

inches.

CuWcft. of water per min- ute.

444H

361K

338M

Other tests were made of this wheel, resulting in an average of 82.925- 1000 horse-power [?], utilizing 69.6-10 per cent, of the force and impact of the water.

Various Mechanical Appliances.

Pklton Wheel— First

Test.

Weight on biakM,lb.

Revolu- tions.

Hone, power.

Head of

over weir,

inches.

Cubic ft.

of water

permin-

ute.

2S4!4

"

(i

Second Test.

46s

256K

i(

257K

Lower Nozzix.

254K

Still Lower.

tt

46s

High Nozzle.

46s

Average horse-power, 107.49-100, or 90.2-10 per cent

Knight Wheel— First Test.

Weight on brakes, lbs.

Revolu- tions.

Horse- power.

Header

water over weir,

inches.

Cubic ft. of water per min- ute.

The cubic inches of water in this test were reckoned on the amount of miner's inches used, allowing 1.40 cubic feet per minute for X miner's inch ihis shows 77. 18 per cent, of the power of the water.

Second Test.

Average per cent, of first test, 76. 5-10. Average per cent, of second test, 71,2-10. These were the only tests made of this wheel, the nozzle breaking and there being no other on hand.

Various Mechanical Appliances. 193

Taylor Wheel.

Weight on Revolu. brakes, lbs. tions.

Horse, power.

Head of water

over weir, inches.

Cubic ft. of water per min- ute.

3121 254

n

Average per cent, of

first

test, 55.1-

Average

per

cent, of second

test, 60.5-10.

The accuracy of the weir measurements may be con- sidered doubtful. From the data obtained it did not ap- pear that the increased discharge due to velocity of ap- proach had been taken into account. To check this es-

FiG. 44. The Pel ion Wheeu

timate of flow the diameter of the nozzle above given could not be used, as it was not accurately measured and the coefficient of efflux had not been established. How- ever, sufficient is known to justify the assumption that the efficiency of the Pelton wheel is at least 86 per cent.

Tests at the University of California. — The latest and most accurate data are derived from a monogram by Ross E. Browne, of the University of California ; these, with the permission of the author, are here given entire.

Hurdy-gurdy wheels are commonly called " Impact

194 Various Mechanical Appliances.

wheels/* though such a name is misleading, and entirely loses its significance when the bucket is given its best form. When a jet of water strikes a stationary bucket shaped as shown in Fig. 45 or in Fig. 46, as soon as the motion has become permanent the wedge-shaped portion of the water shaded with horizontal lines be-

X comes practically station- ary. We have actual im- pact only for a minute in- terval of time — i.e., while Fig. 45. the wedge is forming. Af-

ter this the water is simply deflected from its course, and the bucket becomes almost instantaneously a pressure bucket.

When such a bucket is used for a wheel it is plain that this shaded portion of the water is " carried " and must subsequently escape with nearly the full velocity of the bucket. Its useful effect is therefore very small as com- pared with that of the water actually deflected. No ad- vantage comes, then, from impact ; on the contrary, serious losses are due to it.

The originally flat bucket (see Fig. 45) has been ma- terially improved :

I St. By giving it curvature (see Fig. 46). 2d. By filling in the wedge and making it a part of the bucket. This second improvement brings us to the " Pelton wheel " (see Fig. 53), which is by no means an " impact " but distinctly a " pressure " wheel. By filling in the wedge impact is avoided. The same thing in prin- ciple could be accomplished with the simply curved bucket by having the jet strike one side instead of the centre (see Fig. 47).

A prominent distinction between the Hurdy-gurdy wheel and the Partial Turbine rests in the fact that the former has " open " and the latter " closed buckets. When properly constructed the one is no more an " im- pact wheel " than the other.

Various Mechanical Appliances.

Fig. 47.

The principal sources of loss in Hurdy-gurdy wheels are in general :

I St. The energy remaining in the water after being discharged from the bucket

2d. The heat developed by impact of the water in striking the bucket.

3d. The fluid friction of the water in passing over the surface of the bucket.

4th. The loss of head in the nozzle. The loss in the supply pipe is not charged to the wheel.

5th. The journal friction. 6th. The resistance of the air.

In the formulas below all of these sources of loss but the first are neglected ; and for the purpose of weighing the importance of curvature in the buckets, it is assumed that all of the water escapes from the bucket with the same velocity — i.e.y no water is " carried with the wheel. Let c designate the velocity of the bucket in feet per

second. V " velocity of the jet escaping from the

nozzle. u " " relative velocity of discharge from

the bucket. w " absolute velocity of discharge from

the bucket. Q " " quantity of water supplied per sec-

ond in cubic feet. y " " weight of one cubic foot of water.

L " " useful work (in foot lbs. per second)

under the above conditions. rj " " efficiency of the wheel under the

above conditions. g acceleration of gravity.

5 " " angle made by the discharge end of

the bucket with its line of motion (see Fig. 48).

Various Mechanical Appliances.

Then u v — c

V 2 (l +COS S) ( 3)

And by varying the velocity of the bucket we have for the greatest effi- ciency —

Fig. 48.

(I)

i.e. J the velocity of the bucket should be one-half the velocity of the supply water (the jet) escaping from the nozzle, and this is not very materially modified by intro- ducing the other conditions. Hence the greatest ef- ficiency —

7,= -(i+cos

(2)

The smaller we make d the greater will be this efficiency.

Flat Buckets. — If the bucket is fiat, 5 90 degrees, hence 37, 50 per cent. ; t.e.y 50 per cent, could not be reached with fiat buckets, on account of the sources of loss neglected in these formulas.

A series of experiments were made with such flat buckets (see Fig. 50) with a -inch nozzle.

The curve of efficiency for various

Fig. 49.

speeds, as established from these experiments, is shown

Various Mechanical Appliances.

in Fig. 56. A -inch nozzle gave results but slightly dif- fering from these.

Fig. 50.

The highest result was 40.4 per cent, under 50.2 feet head.

The velocity of the jet being approximately v .98 V64.36 X 50.2 55.7 feet per second, we should have for best efficiency, if the conditions were such as led us to equation (i), the velocity ot point P oi the bucket

27.85. This corresponds to 6.8 revolutions of the

wheel per second, which is marked by a heavy vertical line crossing the curve very near the point of the best efficiency actually obtained.

Fig. 51.

(scale >ft) r

Fig. 52.

Curved Buckets. — If d could be made =0, we should have, under our assumed conditions, jy, 100 per cent. ; w would be o, and the water would simply fall from the bucket by its own weight. Evidently, then, 8 should

Various Mechanical Appliances.

be made as small as is compatible with clearance of the supply jet and the following bucket. Experiments were made with such a bucket as shown in Fig. 5 1 in section, in other respects shaped and set upon the rim of the wheel as the Pelton bucket (see Fig. 53).

(tCAclM.)

Fig. 53. Pelton Wheel.

A -inch nozzle was used under head of 50.4 feet. The best result reached was 65.6 per cent. The curve of efficiency is shown in Fig. 56. The heavy line crossing the curve again shows the best speed as calculated

by making -. This marks a speed about one-half

revolution per second greater than that actually found by experiment.

The Pelton Wheel. — Mr. Pelton kindly furnished a pattern from which buckets were cast, and thirty of them attached to the wheel as shown in Fig. 53. A

Various Mechanical Appliances.

section and an isometric projection of the bucket are shown in Fig. 52. The angle 3 is just sufficient to provide against interference of the discharged water with the buckets following.

The face of the bucket is inclined to the diameter of the wheel.

cmciCNcv

o

p

t

M'

r

)

/

-H

♦

P

zz

Experiments were first made with seven differen set- tings of the nozzle. For direction (Fig. 53) of jet the efficiency was 68.1 per cent, for rf 80.5 per cent., for 78.4 per cent. The nozzle was permanently set to give direction d to the jet.

Various Mechanical Appliances.

The efficiency was then determined for various veloci- ties of the wheel :

ist. With a -inch nozzle giving 82.5 per cent, as best result (see Figs. 54 and 56).

2d. With a -inch nozzle giving 75.6 per cent, as best result (see Fig. 54).

3d. With a Vi"ch nozzle giving 82.6 per cent, as best result.

Doubtless the .nozzle might have been increased to

inch without materially re- ducing the efficiency.

Another set of experi- ments was made with the -inch nozzle under various heads, from 50 feet down to 8 feet, showing a gradual decrease in useful effect (see

Fig. 55).

At 8 feet the efficiency still remained as high as 73 per cent. In experimenting with the curved buckets " the efficiency might possi- bly have been raised 2 or 3 per cent, by attending more carefully to the curve and to the size of nozzle used. Still there was probably a gain of more than 12 per cent, due to the introduction of the wedge in the Pelton bucket.

In comparing the three Hurdy-gurdy wheels experi- mented with, it is evident from Figs. 52, 46, and 45 that the "Pelton bucket" will carry** the least, and the curved bucket the greatest, quantity of water. This

Bo

Pelton Wheel .

y

So

Jo

N- 1

2(

9 S

hiao o' watch in . Fig. 55.

In view of the fact that Mr. Pelton claims a stiU higher efficiency for his wheel, it should be stated that although he furnished the pattern for the bucket, the wheel does not precisely conform in all particulars to his standard.

Various Mechanical Appliances.

"carried" water is the most important of the sources of loss not taken into account in equations (i) and (2). Hence the approximate best speed as calculated from equation (r) differs least from the actual best speed as found by experiment, in the case of the Helton bucket," and most in the case of the " curved bucket " (see Fig.

EmacNCY

g

56). It is perfectly sale to say the Pelton bucket should have one-half the speed of the supply jet for best effect. It is plain that the Pelton wheel has certain advan-

The Partial Turbine here mentioned is a Tangential Wheel with inner feed, and was specially designed for 4 small supply jet.

202 Various Mechanical Appliances.

tages over the Tangential wheel. It is more easily built, has a decided advantage in the setting of the nozzle, and is not so dependent on the precise size of nozzle used. The capacity of these wheels may be doubled by adding another nozzle.

It is quite likely that a wheel considerably larger than the one used at the University could be made to gve a still higher efficiency than the 82 per cent, found. The angles in the pattern for bucket castings could be made more accurate.

The Pan.

The pan, an mdispensable companion of the gold- miner, is pressed from a single piece of Russia sheet iron. It is 12 inches in diameter at the bottom and 15 to 16 inches on the top, the sides inclining outward at an angle of about 30 degrees, and turned over a wire around the edge to strengthen it. It is used in prospecting, cleaning gold-bearing sand, collecting amalgam in the sluices, and, in fact, in every branch oi the business.

Its proper manipulation for washing dirt requires a certain skill, which can be acquired only by practice. The pan, filled with dirt, is submerged in a tub or pool of water and the gravel worked with the hands until all cemented material is disintegrated. The coarse stones are cleaned and thrown out. In washing the residue the pan is held in a tilted position. By a circular motion and by careful use of the water, into which the pan is continually dipped, all the lighter dirt is worked to the top and over the edge (pebbles being picked out by hand) until only the fine gold and black iron sand remain.

The Bate A.

The batea is a shallow wooden bowl commonly used in Brazil and the Spanish-American States for separating, on a limited scale, grains of gold from sand, pyritic mat- ter, and magnetic iron. A disc of 17 inches diameter.

Various Mechanical Appliances. 203

being turned conical I2 degrees, will have a depth of iji inches from centre to surface. The thickness may be of an inch. The outer edge, perpendicular to axis, will require wood 2j4 inches thick for its construction. The best wood is Honduras mahogany

The Rocker.

The rocker is a box 40 inches long, 16 inches wide on the bottom, i foot high, with sides sloped like a cradle, and with rockers at the middle and back end.

The upper end is a hopper, 20 inches square, 4 inches deep, with a perforated iron bottom with half-inch-diame- ter holes. This top hopper is removable. Under the per- forated plate there is a light frame, placed on an incline, upon which a canvas apron is stretched, forming a riffle.

In washing with the rocker the material is thrown into the hopper and water is poured on with a dipper held in

Fig. 57. The Rocker.

one hand, while with the other hand the cradle is kept rocking. The water washes the sand and dirt through the bottom of the hopper, and the gold or amalgam is either caught in the apron or picked up in the bottom of the rocker, while the sand and lighter material are discharged at the end, and the coarse material in the hopper is thrown aside. In California rockers were extensively used before the introduction of ditches, but now they

See paper by Melville Attwood, Transactions Cal. State Geological Soc."

Various Mechanical Appliances.

are employed only when cleaning up placer claims and quartz mills, for the collection of finely subdivided parti- cles of amalgam and quicksilver.

The Tom.

The tom, said to have been an importation from Georgia, was first used in Nevada County in the latter part of 1849. is a rough trough about 12 feet long, from 15 inches to 20 inches wide at the top, 30 inches wide at the lower end, and 8 inches deep. It is supported on timbers or stones, and set on an incline of, say, 12 inches

Section Of The Tom

Fig. 58. The Tom.

(or I inch per foot). A sheet-iron plate, perforated with holes half an inch in diameter, forms the bottom of the lower end of the trough, which is bevelled on the lower side, so as to have the plate on a level.

The material, when fed in from sluices, on striking the riddle (or perforated plate) Is at once sorted, the fine dirt with the water passing through it, while the coarser stuff is shovelled off.

Under the perforated plate there is a flat box set on an incline, into which the finer gravel passes. By the con- tinual discharge of the water through the plate, and with the occasional aid of the shovel, the sand is kept loose, allowing the gold to settle. Since the introduction of sluices the tom has disappeared.

Various Mechanical Appliances. 20$

The Puddling Box.

The puddling box is a wooden box, usually 6 feet square and i8 inches deep, arranged with plugs for dis- charging the contents. The box is filled with water and clayey dirt containing gold. By continuous stirring with a rake the clay is dissolved in the water and run off. The concentrated material collected in the bottom is washed subsequently in a pan or rocker. The puddling box has been used to a very limited extent in California, but in Australia, according to Forbes, no less than 3,950 of them, worked by horse-power, were in use in Victoria alone in i860.*

Amalgam Kettles.

The amalgam and quicksilver kettles are ordinary sheet-iron buckets or porcelain-lined iron kettles. In cleaning up they are especially used as receptacles "for floating the gold amalgam. The amalgam, previous to straining and retorting, is floated in quicksilver in order to free it of all foreign substances.

J. R. Forbes, Mining and Metallurgy of Gold and Silver.'*

Chapter Xiil Blasting Gravel Banks.

Where the deposits are very strongly cemented blast- ing is necessary.

The ordinary method of blasting gravel banks is as follows : A drift is run in from the face on the bottom of the deposit a distance proportionate to the height of the bank (as a general rule not over three-quarters of this for high banks) and the character of the ground to be moved. From the end of this drift a cross drift is driven each way (forming a T). The cross drift is charged with kegs of powder, the main drift is securely tamped by filling it up solid with the material which has been extracted, and the powder is exploded by means of a time fuse or an electric battery. In some instances when the ground is " heavy and bound** several cross drifts are used The amount of powder used is determined by the position, character, and height of the bank, a quantity sufficient only to shat- ter the ground being employed.

Blast at Siuartsville. — The following details of several large blasts are given as illustrating the general facts. A blast of 450 kegs of black powder was made at Smartsville in hard cement with an 80-foot bank, the ground being ordinarily bound with two sides free). The main powder drift was run in from the face of the bank 85 feet, cross drifts being opened each side 40 feet and 85 feet from the mouth. Each cross drift was 45 feet long, and from its ends and centres two " lifters were driven at right angles to it, extending respectively half way to the next cross drifts and to the face of the bank. After charging the cross drifts the main drift was tamped and the powder exploded by means of an electric battery.

ao6

Blasting Gravel Banks.

15'

iplB.

15'

ly

The arrangement of the powder chambers for a 1,201- keg blast made by the Smartsville Hydraulic Mining Company in December, 1868, is shown in the following diagram.

X was a shaft 74 feet deep, from the bottom of which the main drift, A, was driven 185 feet. The cross drifts,

B, three in number, were driven at distances respectively of 70 leet, 120 leet, and 170 feet from the shaft, X. They extended each 20 feet on one side of the main drift and 40 feet on the other side. The several drifts marked C are called " lifters." Each " lifter " was 1 5 feet long. The total length of the drifts aggregated 5 70 feet. They were 2J feet wide and feet high. The cross drifts were charged with 1,201 kegs (25 pounds each) of black powder. The main drift was securely tamped from the shaft to the first cross drift, a distance of 70 feet. The pow- der was simultaneously ignited by electricity at 12 different points.

The ground moved was 270 feet long, 180 feet wide, with an average depth of 100 feet. The cost of the blast was about $6,000.

Blue Point Blast.— A large blast of 2,000 kegs (25 pounds each) was exploded De- cember 29, 1870, at the Blue Point Mine, Sucker Flat, Nevada County. The main drift

-BHf-

X ©SHAFT Fig. 59.

n

208 Blasting Gravel Banks.

was 325 feet long. Commencing at the upper end ol the drift, a cross drift was run 80 feet to the right and 120 feet to the left. Five additional cross drifts of similar length were driven from the main drift 50 feet apart, the last one being opened at a point 75 feet distant from the entrance of the tunnel. There were three lifters in this last cross drift, two in the left arm and one at the end of the right arm. The main drift was tamped from the entrance to the first cross-drift. The drifts were 3 by 4 feet in size. The blast was simultaneously fired at ten different points by electricity. The mass shattered was reported as 200 feet long, 1 50 feet wide, and 73 feet deep.

At the Enterprise Mine, Nevada County, with 250 feet bank, a blast of 1,700 kegs was fired.

Paragon Mine Blast.— In 1874 there was a blast of 700 kegs black powder set off at the Paragon Mine, Placer County. The details of the drifts arranged for the blasts are shown in Fig. 60.

The main drift, A, was tamped for 75 feet from the near end, and the cross drifts tamped 10 feet each way, a space being left in the lifters for the expansion of the gas generated by the expIosion of the powder. The drifts were feet high and 5 feet wide, and the bank was 1 50 high. The blast was fired by electricity, and the ground covered by the drifts was thoroughly shattered.

A blast of 3,500 pounds of giant powder No. 2 was fired, in 1872, in the Harriman and Taylor claim at Gold Run, Placer County, and is reported to have thrown down 200,000 cubic yards of gravel.

Dardanelles Mine Blast. — At the Dardanelles Hy- draulic and Drift Mine near Forest Hill. Placer County, a blast was made with 36,400 pounds of Judson powder (old), shattering about 500,000 cubic yards of cement gravel. The gravel bank had a face of some 1,200 feet in length, with a height of 175 feet. This deposit reposed on a ris- ing bed-rock. Five parallel drifts, 180 feet apart, were run in from the face a length of 70 feet each. From the

Blasting Gravel Banks.

end of each of these drilts two arms (right and left) or cross cuts were driven 70 feet long, thus leaving a space of 40 feet between the ends of the cross cuts from the several main drifts. The powder, in 50-pound boxes, was charged in lots of 1,000 to 1,500 pounds in the different chambers. In each chamber three exploders were placed

B 60'

y

B

70'

3D'

A

3)

Fig. 60.

in the powder, each exploder being carefully connected by an insulated copper wire with the main wires on the outside of the drifts.

The drifts were all well tamped with clay and boul- ders. The wires from the exploders connected outside of the main drifts with two copper wires from an electro- magnetic battery which was situated to the right and about 200 feet from the face of the bank. When every- thing was ready (November 8, 1879) blast was fired. The back ground was raised bodily 4 or 5 feet, and the face was thrown forward.

2Io Blasting Gravel Banks.

At the Blue Tent Mine, Nevada County, in 1880, a bank 200 feet high was thrown down with 43,000 pounds of powder.

Blasting Powder. — Common blasting powder was almost universally used up to 1876. Since that time Judson powder has been introduced, and combinations of black blasting powder and Giant powder also have been experimented with. Giant powder is extensively used for breaking up lava, pipe-clay, boulders, trunks and stumps of trees, for all of which purposes it is found to be very efficient.

Methods of Blasting. — In certain districts it is customary to wash oflf the top or lighter gravel and subse- quently blast the bottom cement. For this purpose shafts 1 5 to 20 feet deep are sunk to the bed-rock, and a small chamber is excavated at the bottom. This chamber is charged with a few kegs of powder and tamped, and a blast is fired by means of a fuse.

The want of proper information concerning the use and application of powder to bank-blasting has undoubt- edly caused a great waste of explosives, and the subject is well worthy of investigation with a view to future im- provement.

In blasting gravel banks it is desirable to thorough- ly shatter the material. To accomplish this purpose one must be governed by the character of the ground in the selection of the powder. In hard cemented de- posits quick powders like the Judson (a low-grade nitro- glycerine powder) and the Vulcan B B are found to work better than black powder ; while the latter does fully as much work in softer ground, a slow-lifting poWder is in such cases all that is requisite.

With very high banks it is more economical to blow out the bottom and not attempt to raise the superincum- bent mass. The charge should be placed so that the line of least resistance is horizontal.

With banks from 50 to 1 50 feet high, and likewise in

Blasting Gravel Banks. 211

cement gravel of ordinary tenacity, the following method has been found to give excellent results.

The main drift should be run in a distance of two-thirds the height of the bank to be blasted. The cross drifts from the end of the main drift should be driven parallel with the face of the bank, and their lengths determined by the extent of the ground which is to be moved. A single T is all that is necessary.

The minimum amount of powder required is from lo to 20 pounds per 1,000 cubic feet of ground covered by the drifts. The quantity used necessarily varies with the character of the gravel. When the banks are strongly bound or the gravel is very tenacious the quantity must be increased. Small blasts, everything else being equal, require a larger amount in proportion to the ground than large ones, varying in practice from 10 to 50 pounds for each 1,000 cubic feet. It is usually expected that a blast will prepare nearly double the quantity of the ground covered by the drifts;

The annexed table is a record of all the large bank blasts fired on the Milton Mining and Water Company's property at Manzanita Hill, Sweetland, Nevada County, during a period of three years. These blasts were made under the immediate direction of Richard Thomas, foreman.

The top gravel had been previously washed off, leav- ing banks from 50 to 1 50 feet in height. The gravel is usually hard, and cemented for 50 feet (rarely higher) from the bottom. Above this cemented material the gravel is comparatively soft and easily broken, and therefore the amount of powder employed is propor- tionately lessened as the banks increase in height.

From the appearance of the ground subsequently washed it was estimated that 225 to 230 cubic feet were shattered per pound of powder exploded.*

♦ " Report upon the Blasting Operations at Lime Point, California, by Lieutenant- Colonel G. H. Mendell, Corps of Engineers, U. S. A.," gives interesting details of large blasts in rock formation.

TABLE XXIV. Bank Blasting at the Manzanita Mine, Sweetland Nevada Co. Cal.

A

B

It of der pet cub. ft. round.

Date.

"S X u

f

c'C

r

¥

W

Feet.

Feet.

Feet.

Cubicfeet.

Lbs.

Lbs.

February, 1 879. .

550,000

March, " ..

173,000

2,150

i,454,oco

15,250

212,000

2,000

April, W

SIO.iXX)

5,500

May,

June, ..

662,000

8,500

(t

?3

1,304,000

16,000

July, - ;:

400,000

August, " ..

f)6

i7

602.00 )

10,500

September," ..

200,000

4,000

41 t(

I2J,<Xx)

2,000

712,000

11,250

15.80 '

October ..

"3

419,000

7,000

January, i83o. .

72A

111,000

2,000

28S,coo

5,100

February, . .

1 T

76

183,000

3,100

April,

13S

973,000

14,500

i(j9,ooo

3,250

May, " W

855,000

16,250

June. ..

27,000

5,625

691,000

13,000

July, " ::

343,000

6,300

August, . .

988,000

14,500

September/* ..

628,000

12,000

November," ..

305,000

5,000

936,000

December, " . .

1,344,000

18,750

March, 1881..

1,418,000

14,000

April, " ..

1,336,000

14,000

35'

87,000

2,500

Mav, " W

553,000

8,750

958,000

13,750

June. " !!

1 no

1,449,000

17,500

(4 44

275,000

3,800

July, ;; ::

613,000

8,000

4t ((

no

672,000

August, ..

157,000

loo

1,397,000

16,000

".45

4( (4

909,000

13,000

September," ..

418,000

1,024,000

15,000

October, " !!

13,000

670,000

8,000

November," ..

lOI

465,000

6,500

180,000

6,500

Totals

202,000

4,500

3,632

5,352ft

30,098,000

425,400

Averages

February, 1883..

65A

1,530.735

9,500

1 March, " ..

2,093,040

14,000

In the blasts here recorded Judson powder chiefly was used, only a small proportion being Black powder and Vulcan B B.

Blasting Gravel Banks.

Firing by Electricity.— The firing of blasts by means of electricity requires that great care should be taken of the wires while tamping, and where dynamite exploders with platinum wires are used the "compound circuit'* is most desirable. A paper entitled "On the Simultaneous Ignition ot Thousands of Mines," by Julius H. Striedinger, published in the Transactions** for June, 1877, of the American Society of Civil Engineers, con- tains much valuable information on the subject.

In charging the drifts the powder (in boxes or kegs) is piled up in rows; two wires, A A and D D (see Fig. 61),

extend along the middle row, the tops of the boxes on which wires rest being removed. The exploders, b, are inserted in giant-powder cartridges and placed on top of the paper covering the powder.

The wires A A and D D are then connected with the wires Y Y' and Z Z', which extend to the battery.

Taiuping. — Great care should be used to prevent the " blowing-out of the tamping, which results not only in considerable loss of effect, but often causes great destruction to property and even to life. It is advisable, when firing blasts by fuse, to tamp nearly the entire main drift. The gravel extracted from the drift is used for this purpose, and should be fairly dry and as free as possi- ble from large stones, which cause great damage in case

214 Blasting Gravel Banks.

of a blow-out. The tamping must be firmly rammed by wooden mauls, so that it will not settle from the roof of the drift. In order to guard against failure through defective fuse it is customary to use' two or three lines, which are simultaneously ignited.

Firing by electricity has the advantage of requiring less tamping and of permitting it to be placed in the cross drifts between the two chambers of powder, which are simultaneously fired — a result that could not be effected by fuse. The force from the explosion from the two chambers, acting upon the tamping from opposite sides, prevents its being blown out ; and therefore when drifts are fired in this way it is necessary to tamp but a short distance in the cross drifts and but a few feet in the main drift.

Owing, however, to the many failures arising from de- fective batteries and connections, the miners generally have abandoned the use of the electric battery.

Chapter Xiv. Tunnels And Sluices.

Tunnels. — Tunnels are run for the purpose of open- ing gravel claims (where open cuts are impossible on ac- count of the formation of the ground), and also to afford proper facilities for removing the washed material.

A tunnel should be driven well into the channel be- fore any connection is made with the surface.

Shafts for Tunnels.— The shaft which connects with the headings should be vertical, though in some cases inclines have been used. Its size is determined by the requirements of the work, and varies, for ordi- nary cases, from 3 by 3 feet to by 9 feet in the clear. When raising from the tunnel due precaution should be taken against accidents arising from the rush of water, sand, and gravel, which is liable to occur on tapping the bottom of a deposit. A shaft by 9 feet should be divided into two compartments, one of which will serve as a man-way. A compartment 4 by 4 feet in the clear is ample for the water-way.

It may be noted that a vertical shaft, when properly timbered, is the most desirable and economical for open- ing hydraulic claims, and with drops of 300 feet no trouble has been experienced. There is no difficulty in connect- ing directly with the tunnel where the work is done well and the mine properly opened. But where washing is going on through a shaft into a tunnel in process of ex- tension, it is convenient to have the shaft located at one side and connected with the tunnel by a short drift. By this means the work in the tunnel can progress while the washing is carried on.

2l6 TUNNELS AND SLUICES.

Shaft Timbering.— Where a shaft is in hard rock, and no man-way is needed, timbering is unnecessary ; but in soft rock or gravel, to avoid any accident or delay the shafts should be strongly timbered, closely lagged, and lined on the inside with blocks (6 to lo inches thick) to within 8 to 30 feet of the surface, the depth being depen- dent on the softness of the gravel. This top, being the first washed ofif, thereby gives the initial grade for the ground sluices. As washing proceeds the upper lining and timbers are removed to enable the material to be drawn into the shaft. A shaft in hard rock can be par-* titioned for a man- way with stoU-timbers firmly wedged and blocked.

No extraordinary precaution is required for the pro- tection of the bottom of the shaft, the material washed being allowed to drop directly on the bedrock, where it soon wears a hole, in which the large stones from the mine lodge and form a pavement. At the junction of the shaft and the tunnel the latter should be increased in height at least 50 or 75 per cent.

Second Sliaft. — With long tunnels it is advisable to sink a second shaft at a convenient distance from the heading. Formerly, as a precautionary measure, a man was placed in the tunnel to watch the washings, and in such cases a second shaft was indispensable. It is now customary, when washing into a shaft, to provide a swing- ing door over the sluice, about 75 feet below its head, and connected by chain and ropes to a signal on top of the shaft which gives the pipe-men notice in case of overflow.

Should an accident occur at the main shaft by its cav- ing or closing up, the second shaft might afford the neces- sary facilities for continuing the work. When a line of pipe is carried down the second shaft for the purpose of assisting in opening the closed one, great precaution must be used in piping, particularly if the closed shaft is filled with water. When this expedient has to be resorted to it is usual to place the pipes in position and withdraw the

Tunnels And Sluices. 21/

workmen before the water is turned on ; and if the block- ade is not broken in a reasonable time the water is shut ofif, men go down and extend the pipes nearer the block- ade, and again the water is turned on, and the operation is continued until the blockade is broken. If the shaft or tunnel is closed by gravel mixed with heavy boulders it is necessary often to employ powder.

First Washing. — The first washings through a shatt should be done with care, and the surface within as great a radius as can be conveniently washed and drawn should be cleared on all sides before taking off the top timbers. Attempts to push this preliminary work have frequently caused an overcrowding of the shaft, resulting in its filling up or caving. It is therefore essential that the gravel should be run so as to avoid the rush of material Irom caves.

Size of Tunnel. — The size of the tunnel is generally dependent on the size of the sluice. It is usually driven 2 to 3 feet wider than the inside width of the sluice, and to 8 feet high. These proportions permit the proper construction of the sluice and give sufficient room for the blocks and for the workmen when cleaning up. The grade depends on the topography of the country.

Location of Tunnels. — In locating the mouth of a drainage tunnel (or of an open cut) that point is to be selected from which the sluices, running on the most direct practicable line, with a given grade, can bottom the maximum extent of the " pay channel at the smallest expense. Due regard should be had to the dump, and allowances made for contingencies arising from changes, such as depressions and holes in the bed-rock.

Where the bed-rock disintegrates on exposure to the air an extra allowance for depth is advisable. This ad- ditional depth is a matter of judgment, and is regulated by the character and peculiarities of the bed-rock, extent of ground to be worked, and the position of the shaft. It is always possible to " ease up" the grade ; but if the main

21 8 Tunnels And Sluices.

line of drainage is once fixed and proves to be too high, it is a source of endless expense, frequently fatal to the enterprise. Many instances could be cited where, for want of properly conducted preliminary investigations, tunnels have been driven on too high a level and thereby the enterprises have resulted in failures.

At the Pioneer Mine, Grass Flat, Plumas County, the original owners in opening their claim ran a tunnel 4,000 feet long. When midway in the channel the tunnel was found to be 22 feet above the bed-rock. The sum of $60,- 000 expended in this work was a total loss, and the sub- sequent purchasers were obliged to expend over $100,000 in properly opening the mine.

Sluices.

The name "sluice** was originally applied by the miner to the sluice box. Subsequently several sluice boxes were joined together for permanent washing, and the word " flume " was used synonymously. The word sluice used in the text refers only to troughs, cuts, or boxes in which or through which gravel or dirt is washed, in contradistinction to the term flume which is applied solely to wooden structures used for water con- duits.

To secure the maximum discharge sluices should be set on straight lines so far as possible, and where curves occur the outer side of the box should be slightly raised, in order to cause a more general distribution of the ma- terials over the riffles. When lines of sluices have fre- quent curves it is customary to make no changes in the grades, although to secure the greatest flow of material doubtless provision should be made to overcome retarda- tion by increased grades at and below the curves. Sluices with drops are highly desirable for saving gold.

Grade. — The facility with which gravel can be moved depends mainly on the inclination which is given to the

Tunnels Axu Sluices. 219

sluices. The question of grade is therefore one of vital importance, and to properly investigate and determine this point great care and skill are requisite. When the topography of the country admits of unlimited fall the grade upon which the sluices arc set should be regulated by the character of the gravel. Where the wash is coarse and cemented, requiring blasting, or where there is much pipe-clay, a heavy grade is necessary. Strongly cement- ed gravel requires drops to break it up.

General Grade Adopted.— Experience thus far has led to the adoption in most localities of what is called a 6 or e-inch grade, meaning 6 or inches to the box 12 feet long, or, say, a 4 to 4}4 per cent, grade. In some places, where large quantities of pipe-clay are washed off, 9 and 12-inch grades to the box are used (6 to 8 per cent.) In others, on account of natural obstacles encountered, a 1 per cent, grade, or 2 J4 to 3 inches per box of 16 feet, is used.

Light gravel containing clay or earthy matter can be moved on an easier grade and with less water than heavy gravel ; nevertheless, when a 4}4 per cent, grade can be obtained it is desirable, as it lessens the labor of handling rocks and more material can be washed. Moreover, as light gravel is generally poor in gold, this deficiency can be made up only by washing large quantities. Light gravel requires that the water should be run with suf- ficient force to carry off the rocks washed through the sluice, and yet be in only sufficient volume to prevent the packing of black and heavy sand. If too much water is used by superincumbent pressure the sand drops and packs the riffles.

The best results are obtained with shallow streams on light grades. Coarse gravel demands from four to seven per cent, grades and a proportionate increase of water. In washing this heavy material the water in the sluice should be deep enough (10 to 12 inches) to cover the largest boulders ordinarily sent down.-

220 Tunnels And Sluices.

As a larger volume of water is sent through a sluice running heavy cement gravel, more material can be trans- ported and washed if a proper proportion of light and heavy gravel is made. The rocks and cement, as dis- charged into the sluices, keep the sand stirred and pre- vent its packing, while the cement, rolling along the sluice, is disintegrated.

At Forest Hill Divide some of the mines use a grade of lo to 24 inches per 12 feet. The reason for this exces- sive grade is the scarcity of water and the heavy material, it being necessary to run rocks as large as can pass through a four-foot flume.

Size of Sluice.— The size of the sluice depends on the grade, character of the gravel, and quantity of water to be used. A sluice. 6 feet wide and 36 inches deep on a 4 or 5 per cent, grade will suffice for running 2,000 to 3,500 inches of water. One 4 feet wide, 30 inches deep, on a grade of 4 inches to 16 feet, will suffice for 800 to 1,500 inches of water, and on a 4 per cent, grade it is large enough for 2,000 inches. A sluice 3 feet wide and 30 inches deep, with a i yi per cent, grade, is suitable for 600 to 1,000 inches.

As to the length, the principle is to construct the line sufficiently long to insure the most complete disintegra- tion of the material, affording ample surface for the grind- ing of the cement, and the best facilities for the gold to settle in the riffles. The length of the sluice employed should be governed by its yield, the rule being to keep extending the sluice so long as the yield exceeds the ex- pense.

Details of Confltructiou.— Sluices of a width of 4 feet and upward are made of i or 2 inch plank, with sills and posts of 4 by 4 or 4 by 6 inch scantling. To guard against leakage of quicksilver it is important that the bottom should be tight. To secure this the bottom planks should be of half-seasoned lumber, free from knots, and the joints grooved and a dry, soft pine tongue in-

Tunnels And Sluices. 221

serted. The bottom and sides are spiked together gene- rally with nails four inches apart. It is not necessary to plane either the bottom or side planks. In many cases the planks are simply fitted well and closely nailed together.

The sills are placed from 3 to 4 feet apart, depend- ing upon the size of the scantling used, which is regulated by the width of the sluice ; thus a 4-foot sluice would re- quire a sill 7 feet long, of 4 by 6 or 4 by 4 inch stuff. The posts are halved into the sills and firmly spiked, and every second or third post should be supported by an angle brace. The bottom planks should be solidly secured to the sills by a liberal use of heavy spikes. The bottom of a new sluice is liable to be raised by the pressure of the water which collects under it and finds no discharge. To avoid this the flume should be heavily weighted down by loading the ends of the sills with stones. In tunnels the ends of the sills can be held down by braces extend- ing to the rock overhead.

North Bloomfield Tunnel Sluice. — The annexed diagrams give the detailed construction of the tunnel sluice box used at the North Bloomfield Mine. The box is 6 feet wide and 12 feet long, with sides 32 inches deep.

To each sluice box are used :

8 Posts 4 inches X 6 inches X 3 (cet 2 inches.

4 Side planks i) " X 16 X 12 "

2Toprails 2 " X 8 " X 12 "

On the outside of the tunnel the sills and braces are longer. The nails for the bottoms are 30/., for the sides 20cl. The side lining, composed of worn blocks when available, is 3 inches thick, 18 to 20 inches deep, and is set to inches above the bottom. The riffle strips, between the blocks, are i Ji by 3 inches and 5 feet 1 1 inches long. The blocks are 13 inches deep and 2054 inches square, and average about 19 to the box. Where

Fig. 64.

Fig. 62.

Figs. 62, 63, and 64. Tunnel Sluice Box at North Bloomfield.

X 6 inches X 7 feet,

Xi4 "

xH

Xi4 "

Xi4 "

Tunnels And Sluices. 223

stone riffles are used the bottom of the sluice is lined with rough plank.

The top sluice on one side is for carrying sipage water when the blocks are being set. It is 13 inches wide and 14 inches deep, and is made of i-inch plank.

Bed-Bock Claim Sluice Boxes. — At the Bed-Rock Claim, Nevada County, the tunnel sluice boxes are 14 feet long, 5 feet wide, and 32 inches deep. The details of a box are as follows :

4 Sills 4 inches X

8 Posts 4 X 6 X 3 ainches.

16 Braces

2 Top rails 2

3 Bottom planks "

3 Tongues I

2 Side planks

2 " " lA"

9 Riffle strips ijf

28 Lineal feet side lining (blocks 3 inches X 20 inches).

28 Lineal feet bracing to hold down sluice, 4 inches X 6 inches. 27 Blocks, 17 inches square, 13 inches deep.

In the construction of a box there are used :

Lumber and side lining, 650 feet, at $20 $13 00

Blocks, 704 $14 986

Nails, 20 lbs. 5 cents i 00

Labor at $2 50 to $3 per day 7 00

Cost per box $30 86

La Grange Sluice Boxes.— At the La Grange Mine, Tuolumne County, a sluice box 4 feet wide, 32 inches deep, and 16 feet long is built as follows :

4 Sills 4 inches X 6 inches X 7 feet.

2 End posts 4

6 Intermediate posts 4

16 Braces i

4 Side planks iH

2 Side linings ij

12 Riffle bars 1%

Aggregating 420 feet of lumber. 36 Blocks, 14 inches square and 8 inches deep.

2 inches.

2

224 Tunnels And Sluices.

To each box 15 pounds of nails are used— viz. :

12 Nails, iod,j side lining to sides.

160 i2d.t braces to posts and sills.

40 20., posts to sills.

76 sides to bottoms.

36 blocks to riffle bars.

32 " " bottom sides to posts.

50 3a/., bottoms to sills.

50 " top rails to posts and sides.

The cost per box was : !

420 feet lumber, at 3 cents per foot $12 60

Labor at $1 to $2 50 per day 2 50

Toul $28 34

RiflBes. — The use of riffles dates back to the earliest days of gold-washing. Blankets, hides with the hair turned uppermost, and grass sods were employed by the primitive South American miners, and also steps cut in the bare bed-rock. In California every variety has been tried, but blocks and rocks are now generally used.

The character of the riffle employed is dependent upon the length of the sluice, while the length of the sluice, in turn, depends upon the hardness of the gravel, and more especially upon the character of the gold — scale gold, with large amounts of black sand and tine sulphur- ets, escaping all riffles for long distances.

Block Riffles. — Block riffles are square wooden blocks 8 to 13 inches deep, set on end in rows across the sluice, with each row separated by a space of i to inches. They are kept in position by riffle strips, i % inches thick by 2 or 3 inches wide, held crosswise on the bottom, between the rows, by the side lining, and secured to the blocks by means of headless nails. Block riffles are also set and firmly held in position by means of soft pine wedges driven between the blocks and the sides of the

Tunnels And Sluices. 22$

sluice. When wedges are used the sides of the blocks should be square where they adjoin one another. A side lining is required in all sluices. In cement claims blocks 3 inches thick, and covering i8 to 20 inches (in depth) of the side, are used for side lining.

Advantage of Block Biifles. — The advantages af- forded by blocks, which should always be used at the heads of sluices, are :

1st. The cross riffle which they make is not excelled by any other form.

2d. Their cheapness under ordinary conditions of timber supply.

3d. The convenience of cleaning up, which can be quickly and cheaply done.

This last circumstance is of especial importance, be- cause it is often desirable to collect the gold at frequent intervals, as it is injudicious to expose amalgam collected in the riffles to wear by the gravel running over it for long periods.

Experience shows square block riffles to be the best for saving gold. The objection to their use is the cost of wear and tear. Rocks are the most economical substi- tute, but sluices set with them require steeper grades and more water.

Life of Blocks.— The life of a block depends on the quality of the wood, the grade, the character and quan- tity of the gravel, and the amount of water. The larger the amount of water (on the same grade) in proportion to that of gravel, the less the wear of the blocks. The quality of the wood varies greatly in different localities. The best and most desirable timber comes from the higher sierra. Wood which is long-grained and "brooms up'* makes the best riffle. Hard timber which wears smooth (as oak) is not desirable. Nut pine is the best, but it is difficult to obtain. Pitch pine answers all re- quirements. As a rule the price of lumber governs the selection.

226 Tunnels And Sluices.

In the 6-foot sluices of the North Bloomfield Mine, with a per cent, grade, the blocks, which are 13 inches deep and 20 inches square, last for a run of 175,000 to 200,000 inches of water. At the Manzanita and French Corral mines the sluices are 5 feet wide and have a grade of per cent. The blocks, of the same size as the last, but of rather poorer timber, have a life generally of 125,- 000 to 150,000, sometimes of only 100,000, inches of water.

At La Grange, in 4-foot sluices on 2 per cent, grades, the blocks, 14 inches square and 8 inches deep, are esti- mated to last an average of six months, during which time about 100,000 to 110,000 inches of water are run over them.

After each run the blocks are turned and replaced in the sluice, if not worn down too much. A block reduced to 5, or at most 4, inches in depth is considered unservice- able. In repaving with old blocks the edge worn down the most is placed up-stream. As the blocks do not fill the whole width of the sluice, the alternate rows are fitted so as to break joints.

Bock Riffles. — In many localities stones instead of blocks are used for riffles, and where heavy cement is washed the former are considered preferable on account of their cheapness. At Smartsville they have been found to serve fully as well as blocks, and are claimed to be cheaper. It must be stated, however, that they are more costly to handle, as longer time is required to clean up and repave the sluices.

The stone riffles as quarried are of irregular size and shape, and are set in the sluice with a slight tilt down- stream. The hard rock used at the Manzanita Mine, Sweetland, Nevada County, costs about $10 per box (14 feet long and 5 feet wide).

Blocks and Bocks. — A system of riffles consisting of a row of blocks alternating with an equal section of rocks has been found to work successfully. This arrange- ment of the sluices reduces materially the wear and tear

Tunnels And Sluices. 22/

of the blocks, and has given excellent results. The block- and-rock riffles are not desirable for those sluices which have to be frequently cleaned up.

liOngtudinal Riffles. — In some districts longitu- dinal riffles, made of scantling placed lengthwise in the sluice, are preferred. At the Paragon Mine, Placer County, where the banks contain many large boulders, the riffles are made of 6-inch scantling i yi inches wide, 8 feet long, separated by blocks i yi inches wide ; and an iron bar, i inches wide and i inch deep and 8 feet long, is fastened on top of each scantling. The grade of the Paragon sluices is i8 inches per 1 2-foot box, and the width of the sluice is 44. inches.

Bed-Rock Riffles.— In the tunnel of the North Bloomfield Mine the lower 6,000 feet are run without a sluice, the bare bed-rock being used. Up to 1877, 7,000,- 000 cubic yards were washed through the tunnel, and an examination at that period showed that the tunnel had been deepened about 16 inches, and, though the sides were worn smooth, troughs and holes were found hollowed out at different places. A partial examination of the tunnel made in the fall of 1882 showed the existence of many holes in the bottom, in some instances 6 feet deep, but the wear on the entire line may be said to average 3 feet, about 22,000,000 cubic yards of gravel having passed through it.

On long sluice lines it is common to use several kinds of riffles.

Braucli Sluices.— Where the topography of the country compels the building of branch sluices, or a light dump requires the frequent change of the tail- ings discharge, great care must be taken in construct- ing the connections with the main sluice ; otherwise, in "turning into** and "turning from a sluice, the gravel forms a bar either above or below the junction.

Where heavy grades can be obtained no difficulty is encountered ; but where the inclination is slight, good

Tunnels And Sluices.

judgment must be exercised in fixing the grades and curves, in order to make the sluices run uniformly and draw the material.

Turn-in Sluice. — The diagram shows a " turn-in " sluice adopted, after many experiments, at the Delaney Claim, Patricksville. It was set with what is perhaps the sharpest curve that can be given, for successful work, to a sluice 4 feet wide and 32 inches deep, on a 3-inch grade to 16 feet.

The amount of water used was from 1,000 to 1,400

Tunnels And Sluices. 229

twenty-four-hour inches. The grade was light, and dump for the tailings could be obtained only by means of direct connection made with the Patricksville main sluice line.

With any decrease of the radius the sluice would not run uniformly, but would deposit tailings. The smallest radius of the curve having been ascertained by experi- ment, the next question that presented itself was. Would the main sluice carry the tailings discharged into it ? As the main sluice was straight, and the general fall of the ground slight, an attempt was made to economize grade and run this sluice, with its original grade of 3 inches to i6 feet, below the junction, but the experiment was un- successful. The main sluice was then taken up, and a i-inch drop was given from the turn-in sluice at the junction, and the first two boxes from this point were set on a grade of 4 inches to i6 feet, while the remaining boxes had a 3)4-inch grade to 16 feet. This improved matters, but material still accumulated in the main sluice at the junction and in the one box below. The turn-in sluice was then given a drop of 4 inches at the junction, and the discharge opening was increased from 11 to 14 feet ; the sluices then ran uniformly.

The outer curve of the sluice was set a half-inch higher than the inner side. The boxes forming the curve were made in lengths of 8 feet each, and a grade of 2 inches given to each length. The head of the sluice was straight, as well as the lower end below the junction.

Turn-out Sluice. — The turn-out " sluice is gene- rally used when the dump-room is very limited. It is more difficult to operate on a light grade than a " turn- in " sluice.

At the La Grange Company's mines the grades varied from inches to 4 inches per 16 feet, and the dump- room was very limited, necessitating many turn-out sluices and frequent sharp curves. As the dumps filled up the sluices were extended, and every available space was utilized which could be reached with a branch sluice.

Tunnels And Sluices.

The opening at the points of divergence was origi- nally made 14 feet wide, and a drop of I inches- given from the main sluice to the turn-out sluice, which latter was set on a " swing of 4 inches to 16 feet.

The sluices thus constructed were found to run satisfactorily ; but on increasing the swing (as became necessary) to 5 inches the boxes on either side of the junc- tion choked, only partially dis- charging the material, which diffi- culty could not be obviated by in- creasing the grade. On increasing the width of the discharge opening from the main sluice, which was gradually widened from 14 feet up to 24 feet, the sluices ran uninter- ruptedly and no further difficulty was experienced. ;8 The first box bottom was cut

in the form shown in Fig. 66 — that is, from a point to full width ; the succeeding half-box, of 8 feet, was high on the outside, set with a slight increase in grade, and given a 4-inch swing. All the other boxes were set with a swing of 8 inches to the box, and on the grade of the main sluice for a total distance of 200 feet, after which it was found necessary to straighten the sluice for some dis- tance to give the water opportunity to regain its velocity. These ex- periments showed that in a 200-foot swing on a 2 per cent.

Tunnels And Sluices. 23 1

grade this was the greatest possible curve that could be successfully given to a 4-foot sluice. The curve, how- ever, could be increased in proportion to the grade.

At the turn-in and turn-out it is necessary to place a board diagonally across the main sluice. This concen- trates the discharge and prevents the forming of bars.

Undercurrents. — In order to relieve the sluices of the finer material, and thereby aid in saving the gold, un- dercurrents are introduced into the sluice line. These may be described as broad sluices set on a heavy grade at the side of and below the main sluice.

Where a -drop off can be made in the main line, par- allel steel or iron bars, i by 4 inches, with intervals of i inch between them, and 10 to 20 in number, according to the size of the undercurrent, are placed edgewise across the sluice. A set of such bars is called a " grizzly." It is set I inch below the sluice pavement, which is raised as it wears down. If too low, the grizzly clogs with gravel.

The coarse material passes over the grizzly, and, if the topography permits, is dropped and picked up again in sluices at a lower level.

The finer gravel drops through the bars into a box about 20 inches deep, lined with blocks and set at right angles to the main line. This box carries the ma- terial to the chute at the upper end of the undercurrent.

This chute is lined with cobbles and provided with " dividers of wood to evenly distribute the material over the surface of the undercurrent. It has a 2 or 3 per cent, grade and gradually narrows towards the lower end.

The undercurrent proper is a shallow wooden box, 20 to 50 feet wide, 40 to 50 feet long, with sides about 16 inches high. It should have, if possible, 8 to 10 times the width of the main sluice. The bottom is made of i-inch plank tongued and grooved, and set on a grade of 8 to 10 percent., according to the smoothness of the riffles em- ployed. It is paved with cobbles, wooden rails shod with strap iron, or small wooden blocks. With the smooth

Tunnels And Sluices.

rails a grade of 12 inches in 12 feet is sufficient; but with blocks the grade should be increased to 14 inches in 12 feet, and with cobbles to 16 inches in 12 feet.

The gravel escaping from the undercurrent is led back to the main sluice.

The chief cost of maintenance is occasioned, not by the undercurrent itself, but by the repairs on the main sluice and grizzly, caused by the introduction of the latter into the sluice line. The running expense of a wide under- current is no more than that of a narrow one, excepting in the slight matter of pavement and cleaning up.

At French Corral, with a tail sluice 5 feet wide, the yield of the first undercurrent, which was 20 feet wide,, was 20 per cent, of the yield of all the undercurrents. An addition of 10 feet to the width increased its yield to 27 per cent, of the total, and the grizzly in the main sluice was not changed.

Table Xxv.

Lengths and Grades of the principal Tunnels in the Mining District of Smartsville Yuba County California,

Average Grade of Tunnel.

Name of Tunnel.

Locality.

length of Tunnel.

Inches per Sluice Box.

Feet per 100.

Feet.

Babb

Timbuctoo

1,200 1,700

$% in. to 12 ft. 6 " to 12 "

Pactolus

Rose's Bar

1,600

Blue Gravel

Sucker Flat

1,100

t% " to 12 "

Pittsburg

6 to 12 "

Blue Point

2,250

6 " to 12 "

Enterprise

1,200

6 " to 12 "

4.t6

Deer Creek

Mooney's Flat. . .

2,200

5 " to 12 "

Tunnels And Sluices.

yc c

S.S

8pp

2

A a.

is

Mo- 00

r " c H? 2-

J? a.

2 err*

£n p

a?

11 w-

S-Sp - 3 r 2.

1|r So:?!

?i mi

2.3- JJEp

iS

88

I

1st

"S§i

M00 Ul "4

5J Ovobo M

U4 o VI o

?

o 6 VI o

Is

: t

H

o

E.

o

??

H o

H o

E.

??

H

e

"8

o

1?

ft o

p

td

W

Tunnels And Sluices.

TABLE XXVI. Lengths Grades and Cost of important Tunnels in Nevada County.

Name of Mine or Tunnel.

Locality.

.

If

.2

Average Grade.

Cost.

Per Sluice Box.

Per Cent.

Bcteton

North Bloomfield .

Karrell

English

American

Manzauiita

Woolsey's Flat

Humbug Cafion

Columbia Hill

Badger Hill

Below San Juan

Sweetland

1,600 9,200t

2,200

2,000t 5,000+ 3,500+

2,aoo

4,400+

5,048+

loH in. to 12 ft.

6 " to 14

7 to 14 -

S Is

$40,000 528,ooot$

160,000+ 92,ooot 90,000 75.ooot

190,0007

Sweetland Creek.. .

Bed-rock

Below Sweetland... French Corral

French Corral. ...

Originally extracted from J. D. Hague's Report on the Eureka Lake and Yula Canal Co. t All figures marked thus arc corrections of the original. % With eight auxiliary shafts.

TABLE XXVI IL Cost of Construction of Tunnel and Sluices at Manzanita Mine,

Expenses.

Labor, etc. : Sup*t and Accoun- )

tant (

Office expenses

Travel of Sup't

Hauling

Miners and laborers. .

Supplies and Materials:

Explosives

Lumber

Lights

Tools and misccl- laneous supplies, f

Steel

Charcoal

Iron

Nails

Blocks for sluice...

Machinery : Pipes, shafting, etc. . Water-power

f 1,400 20 xiq II

19,459 24 1'

Manzanita Tun- nel.

$1,4005

121,12a 48

603 6s

Igal Expenses :

Counsel fees, etc. ... I Taxes :

Taxes before com- 1 I

... fl

pletion. ,

I"

$a5..S99 51

Manzanita Shaft.

Maiuanita Tail Sluice.

",777 99,

"4 35

772 43*

l.3,489 77

1,733 70

1,267 61

6,134 67

ao 00

1,098 43

8,48987

1,417 61.

Total.

$17,577 3oi

$17,476 94 $60,653 75

10,905 ten-hour inches.

NoTB. — The item $25,599 51 shows the cost of driving the Maiuanita Tunnel from a point

Tunnels And Si.Uicks. 235

756 feet from iu mouth to a point of junction with the heading from the shaft, a distance of 851 feet ; cost $30 08 per linear foot. The amount $17,557 30 is the cost of unking the shaft 123 feet and driving a heading from it 93 feet to connect with the lower (tunnel) heading ; cost $81 38 per linear foot. The amount for tunnel and shaft ($43,176 81) is the cost of the entire tunnel to the Milton Company. Previous, however, to the formation of this company the tunnel had been driven in 756 feet at a cost of about $35 per foot, or, say, $19,000 ; adding this $19,000 to the $43,176 81 expended by the Milton Company gives $62,176 81 as the total cost of tunnel and shaft, or nearly $35 per linear foot. The third item of $17,476 94 repre- sents the cost of construction of a tail sluice, 4,774 feet long, from the mouth of the tunnel to the Yuba River, 7 large undercurrents of the most approved pattern, and the labor of putting a flume in the tunnel 1,700 feet long. The three accounts summing $60,653 75 +$19000 (.nmount expended on tunnel before organization of the cdmpany), say $80,000, represents the entire cost of tunnel and sluices ready for washing. Size of tunnel, 8' X 8'.

Chapter Xv.

TAILINGS AND DUxMP.

Tailings. — The refuse material thrown aside in quartz, drift, hydraulic, or other mines, after the extrac- tion of the precious metal, is called tailings." The tail- ings from hydraulic mines are called " d6bns " also.

The number of cubic yards of d6bris from the various gravel mines discharged in 1 880-1 into the streams and valleys of California, between Chico Creek on the north and the Merced River on the south, has been estimated at about 46,000,000. To this amount, according to Professor Price, there should be added 1,000,000 cubic yards from the tailings from the working of 1,500,000 tons of quartz by 12,546 stamps in mills..

Composition of Tailings.— The tailings from mills consist of pulverized quartz particles. The refuse from gravel- washing is of all forms and dimensions, and is com- posed of the most diversified materials. The light particles of soil, loam, and sand are easily carried forward by run- ning water, while the rocks and boulders, though readily transported through sluices, lodge and distribute them- selves, when discharged therefrom, in the creeks and streams in accordance with their size, shape, and specific gravity, and for their further removal the agencies of time and flood are necessary.

Cemented material and pipe-clay are more or less disintegrated and ground down in the process of sluic- ing. When subjected to the action of running water further pulverization and disintegration ensue, the ac- tual amount of which is unknown.

Wear in Running Water. — The wearing down of

Tailings And Dump. 237

solid cobbles and boulders by running water after lodg- ment in the beds of large streams, at a distance from the mine, is not great. When these materials are carried further forward by floods or torrents they move along the bottom until they find permanent lodgment, conse- quent upon a decrease in the grade of the bed of the stream or from some other cause. In water the weight of rocks is materially lessened, and the friction which would be due to their weight is correspondingly de- creased.

The constant collision and rubbing of the harder rocks against each other smooths and polishes them, somewhat changes their form and lessens their surface, and, to a certain extent, reduces them to fine powder but not to sand. Experiments made to ascertain the wear due to erosion of solid materials transported by rivers or streams tend to establish the fact that no perceptible deposit can be attributed to such cause, as the sediment from such wear is found to be a very fine powder, which immedi- ately passes off in suspension.

The distribution of gravels along the course of any stream will be found to be in accordance with their size, form and specific gravity, and distance from the source. Thus the material composing the bed of a stream, which may at its source consist entirely of large boulders and cobbles, will become finer and finer through the succes- sive stages of gravel, pebbles, and sand, until it is finally discharged as muddy water into the ocean.

Effects of Hydraulic Debris.— The working of hydraulic mines in California has here and there given rise to disputes with farmers. These disputes have, un- fortunately, been carried into the domain of local politics, and thereby not only brought into undue prominence, but also exaggerated, and an equitable settlement prevented. Meantime manipulators have taken advantage of the situ- ation to the detriment of both the farming and the mining interests.

235 Tailings And Dump.

The navigable waters affected by the mines are the bays of Suisun and San Pablo and the Sacramento, San Joaquin, and Feather rivers. The smaller and non-navi- gable streams which receive more or less of the sands are (besides the Trinity and Klamath rivers, where so little washing is done that they need not be considered) : the American (tributary of the Sacramento) in the north ; and the Merced, the Tuolumne, the Stanislaus, the Cala- veras, the Mokelumne, and the Cosumnes (tributaries of the San Joaquin) in the south. The quantity of d6bris which has been washed into these streams is unknown, and data based on reconstructed topography in the mining regions are, from the nature of the case, simply guesses. The only available method of estimating with any ap- proach to accuracy the amounts of material mined seems to be that of taking the water used and averaging the duties of the inch, as surveys of the washings are kept up only in exceptional cases.

The inch differs as much as 20 per cent., the nature of the ground mined continually changes, and the character of the sluices varies not only in every district but in almost every claim. These estimates, therefore, must be consid- ered as the mean of many conjectures. It can be safely stated that only in a few instances do any of the ditches discharge the quantity of water which they are rated to deliver according to official statements or in the as- sessors' returns, from which sources chiefly the cubic yards mined have been estimated.

The following tables, XXIX. and XXX., are based on this method. Table XXIX. is from William Hammond Hall, State Engineer, Report of 1880, part iii. p. 24. Table XXX. is from Lieutenant-Colonel G. H. MendelFs Report upon Mining D6bris in California Rivers, 1882, p. 15:

Tailings And Dump. 239

Table Xxix. Table Xxx.

Season 1878-79. Season 1879-80.

Cubic Yards. Cubic Yards.

Table Mountain Creek 3,556,ooo 2,919,375

Butte Creek 84,000

Feather River 12,687,500 4407i770

Yuba River 22,326,500 19,103,598

Bear River 5.55o.ooo 3.35i|246

Dry Creek, No. 2 680,000 132,687

American River 8,604,000 8,615,250

Total 53,404,000* 38,613,926!

In the region south of the American River Mendell's Report shows the discharge of tailings to be 7,414,465 cubic yards.

The differences in the above tabulated estimates, which were undoubtedly prepared with care, show how difficult it is to arrive at exact data. In view of the fact that the details on which the calculations are made are not given, it is impossible to criticise with lairness. It would ap- pear that the duty of the inch is rather too large.:!:

By far the greater part of the material washed remains comparatively near the ends of the sluices in the cafions until removed by heavy freshets. In the Polar Star and Southern Cross mines, at Dutch Flat, I have estimated that nearly 50 per cent, of the material mined is of a cha- racter which need never be carried a mile below the dumps ; it is of heavy rock and cobble-stones, and prob- ably not over 45 per cent, of the whole need ever be- come sandy and sedimentary in character if reservoired before being transported very far ; so that all but about 1 5 per cent, could be held readily behind dams and other obstructions in the cafions.** §

The State Engineer's estimate of quantities washed is based upon the returns of the amount of water used, made by mining superintendents or secretaries, on blank forms fur- nished from the State Engineer office.

t Colonel Mendell's estimate is based u(>on returns of water used in mining, made by the county ossess'vrs to the State Engineer, as provided by law.

X The average duty of the inch for the region draining into the Sacramento Valley is (ac- cording to the tables) 3.6 cubic yards, and for the region south of the American River a.2 cubic yards. The latter is certainly, and the former probably, loo great.

$ Report of the State Engineer, 1880. p. 23.

240 Tailings And Dump.

The coarse detritus which gets into the streams and is subjected to the action of floods is moved along when the grades are over 40 feet to the mile, and is deposited mostly when the grade is lessened to between 30 and 20 feet. " The sands predominate greatly when the grade is reduced to 10 feet and less.*

The finest and lightest material is held in suspension until the velocity of the water carrying it is greatly re- duced. The amount of material suspended in the Cali- fornia rivers has been estimated from tests made of these waters, but these tests have not been continued for a sufficient length of time to afford any reliable results.

The deposition of this material on lands overflowed during high water was one of the original causes of the disputes mentioned above.

Up to the year 1880, the total area in the Sacramento Basin thus affected is estimated by the State Engineer at 43,546 acres, a large portion of which was of little value and had always been subject to overflow.

The catchment area on the east side of the Sacra- mento Valley is very large, and the descent from the high sierra to the valley is very abrupt and precipitous. During the stormy seasons immense quantities of water, caused by rainfall and melting snows, are rapidly dis- charged into the lowlands, where the river channels, having but small areas f and light grades, are unable to carry them off, and floods invariably follow.

The reservoirs which have been constructed by the hydraulic mining companies in the mountains partially mitigate the evils arising from this source.

The Dump.

It is impossible to lay too much stress on the import- ance of the dump, as without it hydraulic mining could not be carried on. Where thousands of cubic yards of

♦ Report of Lieutenant-Colonel Mendell, pp 33 and 34. t Sec vol. ii. p. 7 Trans. Tech. Soc. of the Pacific Coast.

Tailings And Dump. 24I

alluvions are being washed daily from their position, places must be provided at lower elevations where the travel can be deposited. A much larger superficial area is usually required for this than was primarily occupied by the material removed, as the dumps seldom have the depths of the original deposits.

Working on different Bed-rock Levels witli same Dump.— It sometimes happens in adjacent claims with small dump-room that the bed-rock of one is lower than the other. Where this occurs the claim with the highest bed-rock should be the last run ofif.

An illustration of this was afforded at Patricksville, in Stanislaus County, where three claims were worked, one tailing over the other. During the years 1876 and 1877 the lowest claim, called the " Chesnau," was closed each fall, the dump giving out, while the upper ones continued work. With the return of spring freshets the cafion was cleared of the d6bris, and washing was regularly resumed in the Chesnau, continuing as long as the dump lasted. The highest claim was closed while the Chesnau was working, to avoid the too rapid filling-up of the creek. If both upper claims had been worked at the same time the Chesnau would soon have been closed.

Tailing into Streams.— The want of dump is reme- died only in exceptional cases by discharging into a cur- rent or mountain torrent. This occurs where the gold placers are on the borders of large, rapid, and well con- fined streams ; but in the mountains, where the gold-bear- ing deposits are found, the rivers are narrow and shallow, only running water in quantity during the winter and early spring.

Experience at La Grange, on the Tuolumne. — Some of the annoyances and difficulties arising from tail- ing into a stream can be seen on the Tuolumne River be- low La Grange. The river, a large mountain stream which runs over a hard slate bottom, has for 17 miles above the town a fall approximating 18 feet to the mile,

242 Tailings And Dump.

and is well confined by abrupt banks. Opposite the old French Hill dump the river is 500 feet wide, and at La Grange, from which place to its mouth the grade is only a few feet to the mile, its width is 525 feet. Three hun- dred yards below the town, opposite the Light claim, it widens to 750 feet. Down the stream from this point the hills recede for the succeeding three or four miles, but subsequently form prominent banks to the river. During high water, opposite the Light claim, at its greatest width, its average depth was 10 feet, the centre of the channel being 14 feet deep. When the La Grange Com- pany commenced work, in 1872, the bottom of the chan- nel was a few feet deeper.

The Light claim was worked in 1873, and up to June 23, 1874, had discharged 720,086 cubic yards of gravel into the stream. During the same period 975,064 cubic yards were dumped into the river from the Kelly and French Hill properties. The results at the expiration of 21 months were, that the channel opposite the Light claim was filled up, the sluices were run out of grade, the river bed was shoaled on all sides, the water of a formerly rapid stream straggled over the accumulated d6bris with a barely perceptible motion, and it is hardly necessary to add that the claim was closed.

The spring freshets of 1875-76 were unusually severe, clearing the river at the claim for its entire width and leaving a dump of over 1 1 feet along its west bank. In the spring work was resumed, and 48,280 cubic yards were moved in the Light claim and 212,346 cubic yards from French Hill, which was a quarter of a mile up- stream. By September the river was filled up nearly its entire width to the height of the sluices, and the water was confined to a strip 30 feet wide, discharging i foot deep over a bar.

Exceptional Cases. — Where a small amount of tail- ings is discharged into narrow and steep cafions, winter rains and spring freshets suffice to clean them out ; but

Tailings And Dump. 243

where the quantity is large, in spite of the water the ra- vines fill up gradually, and hydraulic mining in these localities ultimately ceases. It occasionally happens that the want of dump-room is obviated by a tunnel, by means of which the tailings are conveyed into large and pre- cipitous ravines, there to await the action of time and water for their further removal.

Chapter Xvi. Washing, Or Hydraulicking.

Cliarging the Sluices. — The tunnel and sluices hav- ing been completed, water is turned into the pipes and washing commences. The sluices are run half a day in order to* pack them. The water is then shut ofif and a charge of quicksilver is put into the upper 200 or 300 feet of sluices, a small quantity being distributed along the entire line except the last 400 feet. In a 6-foot sluice the first charge will be about 3 flasks. The undercurrents are charged at the same time and a little quicksilver put into the tail sluice. Quicksilver is added daily during the run, in gradually lessening quantities, the object being to keep the mercury uncovered and clean at the top of the riffles ; and therefore the charge is regulated by the amount ex- posed to view. At the North Bloomfield Mine, where the main sluice is cleaned up nearly every 12 days, the amount of quicksilver used in a run varies from 14 to 18 flasks. A 24-foot undercurrent will require a charge of from 80 to 88 pounds of quicksilver.

In charging the riffles all splashing of the quicksilver should be avoided. When it is sprinkled into the sluice (a practice to be condemned) it divides itself into minute particles, the bulk of which is easily carried off by the swift stream, while the lighter portions will float even in the clear water. The buoyancy of these small particles is very considerable.

Top water from mining sluices often yields minute globules of quicksilver, and float quicksilver containing gold particles (microscopic) has been taken from the sur- face of the water twenty miles from where the amalgam

Washing, Or Hydraulicking. 245

entered the stream. In one case floating amalgam was observed on the North Fork of the Yuba River four miles below where the tailings were dumped. A flume (con- veying water to a pump) was set above the bottom of the stream, drawing direct without any dam. An examina- tion of the flume subsequent to its removal revealed the presence of about one ounce of gold amalgam, collected at the junction of the boxes.

Commencing Work. — The first work is started near the head of the sluice and the mine opened from that point. As the banks are washed away the bed-rock cuts are driven towards the face of the work and the sluices are advanced. (For blasting see Chapter XII.)

Caving Banks. — In order to cave a bank it is cus- tomary to use two pipes which throw streams from op- posite sides at an obtuse angle with one another, forming a cross-fire, against the lower part of the bank. This cross-fire was supposed to be particularly efficient, but in many cases where large quantities of water and great pressures (2,500 to 3,000 inches with heads of 350 to 450 feet) are employed better results have been claimed from utilizing water in a single stream than from its sub- division through two (or more) pipes. Any surplus water may be allowed to run over the banks, but such surplus should be avoided as far as possible and all the water utilized through the nozzles.

When washing with two pipes, and the dirt caves readily, one pipe should be employed to do the cutting while with the other the falling gravel is washed into the ground sluices.

The face of the bank should be kept square. Advan- tage should be taken of such corners as are left, and, under all circumstances, avoid working into what is called a " horseshoe form. When a cut is rapidly pushed ahead and the work is not squared, the men at the pipes become encircled by high banks, washing can no longer be ad- vantageously prosecuted, and the lives of the miners are

246 Washing, Or Hydraulicking.

imperiled. The majority of accidents arising from caves have been caused by this style of work.

High Banks. — Where the banks exceed 1 50 feet in height it is advisable to wash the deposit in two benches. At Malakofif and Smartsville single benches have been used to the limit of 250 feet, and above this double benches.

When the man at the pipe sees that the bank is about to cave the water should be immediately turned away from the falling masses ; if the cave falls upon the water in the ground cut, a rush of d6bris ensues, and in many instances the men at the pipe have to run for their lives. Such occurrences, arising either from carelessness or ac- cident, cause a loss of time and frequently entail damage to the pipe and machines. Caves, when practicable, are generally made towards evening, the night shift running them off.

Light. — Locomotive reflectors or fires of pitch- wood are used to illuminate the banks during the night. In some large claims electric lights have been substituted. No doubt the latter would be more generally used were it not for the cost attendant on their introduction.

Electric IJght.— The electric-light machine used in illuminating the North Bloomfield mine is of the Brush pattern and nominally of 12,000 candle-power. To run it requires four horse-power, supplied through a hurdy- gurdy wheel. The light is used in two lamps.

The machine, lamps, wire, and connections cost two thousand dollars set up. It has been in almost constant use for two and a half years, running from eight to twelve hours each night.

Its running cost per night is :

Six carbons, inch by 12 inches, Brushes and segments,

Oil, say,

Attendance, half one man's time. Power, 10 inches water, at 2.27 cts., say,

Total cost per night, $2 38

Washing, Or Hydraulicking. 247

The cost of the pitch- wood bonfires previously used was eight dollars per night, and these gave an illumina- tion very inferior to that of the electric light.

The lamps are placed in the open, where they are subjected to the severest winter storms without injuri- ous effect other than the increased consumption of car- bons.

Continuous Work. — The washing should be con- tinuous and no water be allowed to run to waste. It is therefore requisite to have several faces or openings, so that the water can be used from time to time on them whilst the cuts are being advanced and the sluices length- ened. These cuts, or " ground sluices," as they are called, are trenches made in the bed-rock towards the face of the bank washed, for the purpose of collecting the water and material and conveying them to the sluices. Some- times these cuts are very deep, say from 60 to 70 feet, and occasionally the expense of making them forms a large item.

When a claim is running the sluices are always guard- ed. As a protection against theft, where claims are worked intermittently, the sluices are run full of gravel before turning off the water.

Cleaning up. — The length of " runs " is dependent upon many circumstances, but chiefly upon the wear of the pavement. Some claims are cleaned up every twenty days, others are run two or three months, whilst a few, where the water season is short, are cleaned up only every season. All pavements should be cleaned up as soon as they begn to wear in grooves. Where a large quantity of water is used, and a relatively large amount of ground washed, it is considered advisable to clean up the first 1,000 or 1,800 feet of sluices (which are paved with blocks) every two weeks. With a gang of miners this work is done ex- peditiously, not occupying over one half-day. The tail sluices are cleaned up only once a year. The undercur- rents should be cleaned up whenever quicksilver is found

248 Washing, Or Hydraulicking.

spread over their lower riffles, with tendency to discharge over their ends.

When it is decided to "clean up," the bedrock and cuts are piped clean. No material is turned into the sluices, clear water alone being run until the sluices are free of dirt.

When thus prepared only a small head of water, such as men can conveniently work in, is turned through the sluice, and the blocks are taken out by means of crow- bars, washed to free them from amalgam, and laid at the side of the sluice. This is done in sections approximating 100 feet. Between each section one row of blocks is left in the sluice. These rows serve as riffles to prevent the gold and quicksilver from passing down the sluice. After the first section of blocks is taken up men follow the gravel and dirt as these are slowly washed down the sluices, and pick up the quicksilver and amalgam with iron scoops, with which they are put into sheet-iron buckets.

As each riffle is reached the amalgam and quicksilver are collected, the block riffles removed, and the residue is washed down to the next riffle, and so on down the en- tire line of sluice. When this operation is completed the water is turned off and the workmen attend to the nail- holes and cracks in the sluices, " creviceing '' with silver spoons to obtain the amalgam contained in them. After this the side-lagging is overhauled and the blocks are re- placed. Where the sluices are of great length the lower portions are usually lined with heavy rock, which can be used for longer periods without cleaning up.

It is customary in mines which have very long sluices, and which are run at night, to clean up during the day as long a section as can be cleaned and put in order for fur- ther work, and to resume washing at night, until the whole line is cleaned up. At the end of the water season the en- tire works are cleaned up and put in order for the next season's run.

Washing, Or Hydraulicking. 249

Treating the Amalgram, — The quicksilver and amalgam obtained is well stirred in buckets, and the coarse sand, nails, and other foreign substances which float on the surface are skimmed off. This residue (which holds considerable amalgam) is concentrated by washing in pans or rockers, and the concentrations ground in iron mortars and treated with more quicksilver. Any base material which floats on the surface of the bath is melted by itself to a base bullion. The remainder is added to the fine amalgam. The amalgam is strained from the quick- silver through drilling, and the dry amalgam is retorted in iron retorts.

Retorting. — Where the amount of amalgam obtained is small the hand retort is used, but at large gravel-mines the cast-iron retorts are made stationary, similar to those used at gold and silver quartz mills, only that they are smaller. Where large quantities of amalgam are retort- ed and the furnaces when fired are left unattended, as is frequently the case, the retort, which is set immediately above the fire, becomes overheated. The weight of the metal which it contains then causes the retort to " belly," which ruins it. To overcome this difficulty the retort should be set with supports and arranged with the fire to one side, that the heat may be evenly distributed over it. Retorts thus set are found to work well in practice. (See Figs. 70, 71.)

Before the amalgam is put in the retort the interior is coated with a thin wash of clay, which prevents the amal- gam adhering to the iron.

The amalgam should be carefully introduced and evenly spread. The iron pipe which connects the back end of the retort with the condenser must be clear of all obstructions, and under no circumstances should the amalgam be spread so that the pipe can possibly become choked, as in that case an explosion would probably ensue.

To avoid any danger arising from this source, after the cover has been put on, luted with either clay or a

Washing, Or Hydraulicking.

Washing, Or Hydraulicking. 2$ I

mixture of clay and wood-ashes, and securely clamped, the fire is lighted and the heat gradually raised, a dark- red heat being all that is necessary to thoroughly volatil- ize the quicksilver. Towards the end of the operation the heat is raised to a cherry-red color, at which it is kept until distillation ceases. The retort is allowed to gradu- ally cool, and when cold is opened.

During the operation the condensing-coil at the back of the retort should be kept cool by a continuous supply of fresh water entering from the lower end of the box which contains it, whilst the discharge of warm water is effected above.

The retorted bullion is cut or broken in pieces and melted in a well-annealed black-lead crucible, and the gold cast into bars.

Chapter Xvii. The Distribution Of Gold In Sluices.

In cleaning up sluices the largest portion (approximat- ing 80 per cent.) of the gold caught is found in the first 200 feet. The gross yield of the Gardner's Point claim for the season of 1874 was $63,000 for 100 days' run. Of this amount $54,000 were obtained in the first 1 50 feet, and $3,000 were taken from the undercurrents. The re- mainder was found lower down along the sluices. The first undercurrent was 790 feet distant from the head of the sluice, and yielded 50 per cent, of the total yield of the undercurrents. The second undercurrent was 78 feet dis- tant from the first, with a drop of 40 feet between them, and it contained 33 per cent, of the gross undercurrent yield. The third undercurrent was 91 feet distant from the second, with a drop of 50 feet between them. Its yield was nearly $500.

It sometimes happens that a hundred or a hundred and fifty feet at the head of a sluice are covered with gravel during the greater part of a run. In such cases the gold is found farther down. In the North Bloomfield tunnel the upper 300 feet of the sluice are generally filled from one to five feet deep with gravel, and still this por- tion yields much more amalgam per linear foot than the succeeding 300 feet of sluice. The following data from the report of this company for the year ending October 31, 1876, are worthy of note, as showing the position of the gold in the sluices at " No. 8 claim, where some 700,000 inches of water were run, washing 2,919,000 cubic yards of gravel :

The Distribution Of Gold In Sluices. 253

Sump $1,51000 0.80 per cent, of gross yield.

Flume (1.800 ft.) 176,900 73 92.00

Tunnel below flume. ..,. . 7,29000 3.75

Tail sluice (300 ft.) 1,800 00 0.95

Undercurrents. 5,235 00 2.50 "

$192,735 73 100.00

Mr. P. Wright, assistant engineer for water-supply, Beechworth District, Australia, in giving his experience on the subject of the distribution of gold in sluices, says : With a sluice 12 inches wide, on an incline of one foot to 48 feett using 600 gallons per minute, I have found 95 per cent, of the gold within three feet of where the gravel was filled, into the sluice — where the gold was lying on a smooth board, and yet a powerful current failed to move it.''*

Distribution in Tail Sluices.— The North Bloom- field tunnel (8,000 feet in length) has 1,800 feet of sluices, paved with blocks at its upper end ; but in the succeeding 6,200 feet no sluices are used, the tailings being allowed to run on the bare bed-rock (a tough slate).

From the rock-cut at the mouth of the tunnel a sluice paved with rocks receives the tailings. From here on they are carried through sluices and cuts and distributed over undercurrents which are set on different grades, paved, in some' instances, with rocks and blocks, and oc- casionally arranged with longitudinal riffles covered with strap iron. The grizzlies used are made of wrought iron, I by 4 inches in size, set on edge. The discharge from the several urfUercurrents is taken up by the main sluice and subsequently redischarged over the succeeding un- dercurrent until the lowest sluice and undercurrent final- ly discharge the tailings into the caRon. From December I, 1876, to June I, 1877, 354,000 24-hour miner's inches of water (2,230 cubic feet each), conveying the tailings, passed through the main sluice and tunnel and were discharged through the tail or lower sluice and undercurrents.

♦ The Gold Fields and Mineral DiAtricts of Victoria," R. Brough Smythe, p. 133.

The Distribution Of Gold In Sluices.

The annexed sketch shows the general arrangement of the tail sluices and undercurrents, which latter were sub- divided into compartments, as indicated.

96 ft.

Fig. 72.

The distribution of the gold along the line of sluices and in the several undercurrents was as follows :

Tail sluices from December i, 1876, to June i, 1877, miner's inches of water, 24 hours each, 350,000.

150 feet at head, down to No. i Undercurrent, yield $3) 150 00

150 feet, remainder of sluice, yield 350 00

Total $3,500 00

No. I Undercurrent — Size, 24 by 36 feet; grade, 13 inches in 12 feet ; chute, 2 feet wide at opening, contracted to 10 inches; iron-rail riffles. (The undercurrents are divided into four compartments. A, B, C, and D.)

A yielded

loSK

ounces

amalgam.

B

83%

" 3 clean-ups.

D

31

Chute

46M

tf

3i6ii " Value, $1,920.

No. 2 Undercurrent — Size, 24 by 24 feet; grade, 12 inches in 12 feet; chute, upper end feet, lower end 2 feet ; iron-rail riffles.

A yielded ounces amalgam. 36M

P D Chute

2 clean-ups.

Value, $874.

The Distribution Of Gold In Sluices.

No. 3 Undercurrent — Size, 24 by 36 feet ; grade, 1 5 inches in 12 feet; chute, feet upper end, 2 feet lower end ; rock riffles.

36 ft. It

Tail Sluices and Undercurrents.

n.

A y

lelded

5oJi

ounces

amalgam. '

B

35

18K

2 clean-ups.

D

Chute

8>i

Value, $883.

No. 4 Undercurrent — Size, 20 by 36 feet; grade, 12 inches in 12 feet; rock riffles.

yi ounces amalgam. Value, $430.

No. 5 Undercurrent (constructed in March) — 150,000 miner's inches of water; size, 24 by 24 feet; grade, 12 inches in 12 feet; chute, 2}i feet upper end, contracted to 2 feet lower end ; riffles i by 4 inch lumber, cov- ered with strap iron ; nails i inch apart.

A

yielded

ounces

amalgam.

B

n

Sh

y I clean-u

D

ti

Value, $150.

No. 6 Undercurrent— Size, 24 by 36 feet; grade, 17 inches in 12 feet ; rock riffles; chute, 2}4 feet upper end, 2 feet lower end ; 1 50,000 miner's inches of water.

The Distribution Of Gold In Sluices.

A yielded 8 ounces amalgam.

C " 3H "

D " 3

I clean-up. Value, $115.

The total yield of the undercurrents and tail sluices, for the period mentioned, was $7,872, while that of the claim was $145,000.

The amalgam from the main sluice is worth from $7 50 to $8 50 per ounce Troy, whereas that of the under- currents varies from $6 to $6 20 per ounce Troy.

The result of the undercurrents and tail-sluice clean- ups for the year 1876-7 was as follows:

Yield.

Cut A to B 334 ounces amalgam.

Tail sluice B to C i,38o>

Undercurrent No. 1 648

2 28o?i

3 .253% "

4 143%

5 U months.. ]

Total in cafton 3,170 "

This amount (3,170 ounces) equals in value about 7 per cent, of the total yield of the mine for the fiscal year, dur- ing which period 595,500 miner's inches of water have been used, extracting $291,116 90 gold.

Comparing these final results with those of the pre- vious year, 1875-6, the metal is found distributed through- out the sluices and undercurrents in the same relative pro- portions.

This fact is noteworthy, since in 1875-6 the bulk of the material moved was "top gravel," while in 1876-7 a much larger proportion of " cement gravel " was run through the sluices.

In the heavy cement at French Corral and Manzanita

The Distribution Of Gold In Sluices.

a high percentage of the gross yield of the mines is found in the undercurrents.

Hydraulic mining in the " cement claims " is carried on under great difficulties. An exhibit of the workings of the sluices of a representative cement claim (French Corral) is here given, and the contrast thus afforded with the workings of sluices in the majority of cases is most striking and of especial interest.

The washings from the French Corral mine, after pass- ing through the new tunnel, are successively distributed over nine undercurrents before they are finally discharged. The sizes and arrangements of these undercurrents are given in the accompanying table.

TABLE XXXI. French Corral Mine Undercurrents etc.

Undercurrents.

Secondaries.

Main Sluice

containing

Grizzly.

11

r

Js

O

Bottom lined with

!

Jo

Feet.

Feet.

Per Cent,

Feel.

Feet.

Per Cent.

Feet.

Feet,

No. I

4a

ao

Blocks 6'' wide, 4" deep..

"

a

ao

ai

" 3

to

(Blocks for 14 ft

1 Longitudinal rails, a8 ft..

4

ao

)i blocks ;XraiLi

a8

ao

4"

ao

a8

" 7

4a

ao

u u

az

za

8

ao

"

a8

It -

ao

u

xa

a8

From January 14 to October 3, 1877, there were 163,263 miner*s inches of water discharged over these undercurrents, and the corresponding yield of the wash-

Grade 15 inches in 14 feet.

2S8

The Distribution Of Gold In Sluices.

ings was $201,284 36 gold, per cent, of said amount being found in the undercurrents, distributed in the fol- lowing proportions :

TABLE XXXI A. VtWd of the Undercurrents etc, at the French CorrcU Mine.

Amalcam Yield in lbs. Avoinlufmis.

1-

Undercurrenu.

Secondaries.

Nos.

a

a

Lu.

67

a4H

"X

Sh

t

9M

As a further illustration of the distribution of gold in the sluices of hydraulic claims, a classified statement is gven showing the workings of the sluices at the Man- zanita Mine, Sweetland, Nevada County, from December 20, 1876, to October 3, 1877 :

Table Xxxil

Date of Clean- up.

%

Amalgam Yield in lbs. Avoirdupois.

e2

u

33K

H

89

Lons Sluice by Section.

£

a

January4

April a3

Junes

8,6a6

ai,49i 99,187 15,868

16,958

30

8K

aao

54

5a6

40K

♦7.734 87 15.970 53 90,338 51 ax. 56a 47 i5,40X 70 15.970 53 46.307 X9

3,aaa 4"

83J4

August 9

September a9

From top Mine

worked in March and May.

1

37K

ia4

a8

37

Toul

"58,494

561H

$146,408 ax

The Distribution Of Gold In Sluices. 259

The arrangement of the sluices here is as follows :

1st. East cut contained, average 40 boxes.*

2d. Tunnel " " 120

3d, Long sluice 300 "

4th. Undercurrents (8 to commence, 10 at end).. 50 "

The long sluice is divided into six sections, each sec- tion containing the following number of boxes :

1st section, 29 boxes, to second angle below tunnoL

2d

' 56 "

Pease Ravine.

3d

Buckeye Point.

4th

67 "

Armstrong Ravine,

5th

Quinn's.

6th

63 "

Lower.

The sluices in the cut are 4 feet in width, while those in the tunnel and the long sluice are 5 feet wide, all of them having a side lining of blocks 3 inches thick.

The riffles used in the cut sluices are hand-sawed blocks, 13}4 by 13 by 10 inches, and those in the tunnel sluices are also hand-sawed, 13 by 13 by 10 inches, and 17 by 17 by 10 inches ; about half of each. In the long sluice quarried granite rocks 18 inches thick are sub- stituted for block riffles. The grade along the line of the cut and tunnel is 7 inches in 14 feet, while that of the long sluice averages 9 inches in 14 feet, with drops of 6 inches at each angle.

The undercurrents (10 in number) are similar to those used at the French Corral mine. They are 42 feet long (the apron over which the water is spread forms a part), 20 feet wide, set on grades ranging from 10 inches to 16 inches per box, and are paved with blocks 6 by 1 7 by 4 inches in size.

The three following tabulated exhibits are self-expla- natory, and show in the Manzanita mine the results pro- duced by widening the undercurrents.

Each box 14 feel in length.

Co

a i

ids

.C/3 Jw

JO -JUaO J9<£

i,i'

s

&.8

if

tip

tn ♦

JO -JUOD i3J

vox©

JO -juM aaj

? 1

:

4- ;

f

nil

It

JO juao jaj

Ovtx

No

JO -juao Jj

:

8S.8iC:8;5{?8i?

en

N Jo

s 1

JO luao w J

1

JO -juao aaj

00 j

:

U

n

JO -juao aaj

vS

Co

JO -jiwo iaj

: :

2 :

:

M

*8.

It

1 §

JO -JUaO J9J

: :

Co

JO -juaD 4a<£

m

pa

g

i i ii ibiS

i

1!J

!

Total yield of under- Total yield of bullion. .

1 r : ', s r . J : r

M O O OOM OkM 4k W N M n

:ffiiim:i!|

f

;

Per cent, of U. C. yield.

Ov

Per cent, of Total.

If a?

It

M

:

Per cent, of U. C. yield.

Per cent, of Total.

00*

f

M

eweS If

§

Per cent, of U. C. yield.

4k

Per cent, of Total.

If

u

i!

Is

8j;

c*?dc*5

ml

f

i p

Per cent, of U. C. yield.

o

Per cent, of Total.

en

Hi!

S. 2.

M

Per cent, of U. C. yield.

Per cent, of Total.

Utuiwi OlAtn QOttnVn

M Ol

? 1

f

;

Ik'xMOtCiowi-i-saOO

Per cent, of U. C. yield.

P

S2

14 .k

Per cerit. of Total.

h

i?

r

;5

!

M

M

.9 e

<sj

Ov M

o

%Jr

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nm

'S s-

8 S;

a

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i£

!i.8 8S. 8 8%

kt

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M

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m

s

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g

8888 88?8

M

M

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rs,

c

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s,

8 ft ft

8 88 8 8 8-2.

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1"

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-:§

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ro w

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tx

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till mi

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ft :?

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R

1 %

00 m

;i §.1ft;

5

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i.

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&S .

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8

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ft

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i%

: : ': Ji 1

ft

% t

; s

Jg L'l

l|l=ili

d d

11'

o

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go

llf

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3

3 g

3 g S

S s s

g £ g

g 2

6 8 £

g 1! £ E 8 S

E c"*"

.2'"2

Se

o p

b. U.

b. Cb

bu

b. is.

b. Hb. h.

t- U.U.U

c

s

Chapter Xviii.

Loss Of Gold And Quicksilver.

Loss of Quicksilver. — There is an unavoidable loss of quicksilver, the amount of which depends on the char- acter of the gravel washed, the quantity of water used, the grade, length, and condition of the sluices, and the number of days run. The use of a long line of sluices, kept in good order, and the employment of undercur- rents, tend to diminish it.

JLa Grange* — The aggregate amount of quicksilver lost at the La Grange Hydraulic Company's mine in run- ning six claims, during a period of two and a half years, aggregating 1,520* days (24 hours each), washing and moving 2,275,967 cubic yards of gravel, and using 1,533,728 miner's inches of water (2,159 cubic feet each), was 553.75 pounds.

The exact loss of quicksilver during four years* work on the various claims of this company amounted to 1,200 pounds.

North Bloomfleld. — For the year ending Novem ber 3, 1875, the North Bloomfield claims used 464,600 miner's inches of water (2,230 cubic feet each), and 9,649 pounds of quicksilver were employed in the sluices.

The loss of quicksilver at the respective claims was as follows :

Name of Claim.

Miner's inches used.

Length of Sluice.

Loss of Quicksilver.

No. 8

386,972 51,550 26,000

Feet. 1,800

Lbs, PercU

Woodward

Eisenbeck

The aggregate number of days* work of all the claims. 63

Loss Of Gold And Quicksilver.

The large losses at the Woodward and Eisenbeck claims are attributed to old and poor sluices and steep grades. For the year ending October 31, 1876, the loss of quicksilver at the same claims was as follows ;

Name of Claim.

, Miner's inches used.

Length of Shiice.

Loss of Quicksilver.

N0.8

700,000 30,000 56,200

Feet. 1,800

Lb$. 8,351

Woodward

Eisenbeck

In 1882 the loss of quicksilver at the North Bloom- field mines, with a use of 1,000,000 inches of water, was 3,390 pounds.

The following table shows the total number of inches of water run, total corresponding amount of gold col- lected, and loss of quicksilver at the North Bloomfield mine from 1876 to 1882 inclusive :

Table Xxxvi.

Water used. Inches.

Bullion produced.

Loss of Quicksilver.

i88i*

740,650

793,999 918,983 863,820 744,600 988,250

5585,752

$200,366 54 292,382 95 312,279 97 331,759 76 287,924 18

236.935 14 386,146 23

$2,047,794 77

21,512 lbs.

In rock sluices which are run long periods without cleaning up the loss of quicksilver is very great. The 24- foot undercurrents at French Corral and Manzanita mines

Shut down by injunction four months.

Loss Of Gold And Quicksilver. 265

are estimated to lose from 7 to 8 pounds of quicksilver per run of 10 weeks.

Delaney and New Kelley Claims. — The annexed table shows a run at the Delaney and New Kelley claims, in Stanislaus County, where the grades are light ; the de- tails give the amount of quicksilver charged, loss of quicksilver, quantity of water used, and the cubic yards of gravel mined, with all attendant costs.

There was more water used in the Delaney than in the Kelley, and the sluices of the former are much shorter than those of the latter. The composition of the amaU gam obtained at the Delaney was as follows :

Quicksilver 65. 19 per cent

Gold 34.81

Total 100.00

One hundred and fifty-eight pounds of this amalgam were retorted, from which 90 pounds of quicksilver were distilled, showing a loss of 12.62 per cent. The retorted gold weighed 5.5 pounds, and, after melting, 52 pounds — a decrease in the weight (from slagging off impurities, lead, etc.) of three pounds, or 5.76 per cent. The fineness of this bullion was .895.

Loss of Gold. — The most efficient means of saving gold from cement gravel are a liberal use of the best shat- tering powder, breaking the cement before it is washed, and the introduction of several " drops,** when possible, along the line of the sluices. Frequent drops and short lines give better results than a long, continuous line.

Gravel moving in sluices is subjected to a grinding and scouring process which alone is not sufficient to dis- integrate the cement gravel unless the sluices are of great length. The lessening of grades and the use of undercur- rents tend to diminish the loss of fine gold. Extensive lines of sluices and undercurrents are expensive to build and keep in repair. Like the last concentrator, the last undercurrent will always catch some metal.

Loss Of Gold And Quicksilver.

"5

5?

:i?

s

?j

a

Quicki

erdea

up aft

Run

m in

M

if;

tn

vO

oo

tm

Co

?

o

2'

Oo

tn

11

o

4'

p.

- a

t

oo

E

4?

O

&

3;

u 3

ei

en

fnt

%

H

s

55

"8

oo

s

s

5?

s

0)

Q

z;

s-8-

:s g g

s ?-s

S E g

fcri

which gravel argest

.

o

M M

c a S

— 2

g

Iq

rade uicej ight

S e S

2 o

r;

3

cs were set unt of water gravel was

8

O

Ip

sluic amoi The

o

if?

73

e

3

S

tf ii

s § "

o iz;

V

U)

s

Loss Of Gold And Quicksilver. 267

While the knowledge of the quantity of gold in gravel banks remains as imperfect as it is at present, the simple and well-known appliances now in use are the most con- venient and economical, and the excuse so often given for small yields — viz., loss of microscopic gold, and bad sluices — can be set down as one of the preUminary in- dications ol a bad investment.

The loss of quicksilver in sluices would seem to in- volve the loss of gold, but it is practically impossible to determine to what extent this is the case. There are many conflicting opinions as to the amount of fine, floured, and *'rust'* gold which escapes, but in properly constructed sluices the appliances already known save all that can be economically or profitably caught.

In substantiation of this can be cited the work done in 1872-6 at Gardner's Point. The number of inches of water used at the claim during this period is not known. The number of cubic yards of gravel moved has been ap- proximated from the best obtainable data and an inspec- tion of the property. From 1872 to 1874, inclusive, about 148,000 cubic yards of dirt were mined. In 1875 the claim was run full time only fourteen days. In 1876, 40,- 000 cubic yards of gravel and 260,000 cubic yards of lava ashes were washed. The gross yield from 1872 to 1876 was $140,000.

The tailings from all these washings were caught and confined in a ravine situated a short distance below the claim. The length of the sluices through which the gravel passed was 1,378 feet, with three undercurrents. In 1876 the ravine, supposed by many to be exceedingly rich, was cleaned up, and its gross yield was $1,168, not one per cent, of the total receipts from the washings.

Chapter Xix. The Duty Of The Miner'S Inch.

The quantity of material that is washed by an inch of water in twenty-four hours is called its "duty," Esti- mates of the average duty have of necessity differed greatly, since the inch itself denotes a varying discharge of 1. 20 to 1.76 cubic feet per minute in different parts of the State. Therefore the determination of the "duty '' is good only for the specific condition under which it is made.

The circumstances by which it is affected are, the quantity of water, character of the material washed, height of banks, use of explosives, size and grade of sluices, and class of riffles. The sluice affects the duty of the inch in so far as its capacity regulates the quantity washed.

The banks of the mines which discharge their tailings into the American River consist principally of small, fine sediment, disintegrated rock, and materials which are easily moved. The duty of the inch in this locality is as- sumed by the State Engineer to be 4) cubic yards ; while at Dutch Flat, in the deep washings, he found it to ave- rage only from 1.4 to 2 cubic yards.

The duty of the inch in the mines which " tail " into the Yuba River is estimated by the same authority to be 3.5 cubic yards. The gravel deposits here are composed of all grades of material.

The following table from Lieutenant-Colonel Men- dell's report shows the State Engineer's estimates of the

duty of the inch in various localities :

The Duty Of The Miner*S Inch. Table Xxxviii.*

Name of Streams.

Quantity of Water used in Mining and dis- charged into beds of rivers in 34 hours.

State Engineer's Estimate of the Duty per Inch.

Amount moved.

Table Mountain, or Dry Creek

Inches.

833,250 24,000 1,259.363 5,458,171 1,117,082 44,229 1,914,500

Cubic Yards.

3H

3H

4H

Cubic Yards.

2,916,375

84,000

4,407,770

19.103,598

3.351.246

132,687

8,615,250

Buite Creek

Feather River

Yuba River

Bear River

Dry Creek No. 2

American River

Total

10,650,595

38,610,926

The average duty of the miner's inch in the deposits mined and discharged into the San Joaquin and its tribu- taries, according to Lieutenant A. VV. Payson, Corps of Engineers, U. S. A., is shown in Table XXXIX.

In discussing the subject Lieutenant Payson says : " I have thought it fair to allow for the larger hydraulic mines 2j4 yards per inch ; for the ' Jenny Lind and many of the smaller claims with low banks, deficient head, grade, and water-supply, 2 yards ; while in numerous instances of placer, river, and drift mining, where excavated material is thrown into sluice-boxes, I have varied the amounts ac- cording to my knowledge of the circumstances. . . . The quantity for Calaveras is based on the probable future water-supply."

From empirical data at the Jenny Lind claim, with a grade of the tail sluices of to -j, the quantity moved was estimated at 2.4 yards per inch. The material was coarse cemented gravel which required the use of powder.

At Cherokee Flat, with generally very fine material, high banks, head of 300 to 350 feet, and grade j'f, 5.5 cubic yards are reported by the superintendent as the duty of the inch.

See also Report Sute Engineer, 1880, part Ui. p. 94,

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At Dutch Flat, in Nevada County, the duty of the miner's inch has been estimated at certain mines to be as follows:

Table Xl.

Name of Mil.

Inches of Wa- tcr used.

Total Cubic Yards moved.

Cubic Yards

moved pr Inch

of Water.

Southern Cross

299,144

412,070

91,409

247,062

598,050 618,130

326,147 2.057,400

Polar Sfar

Franklin

Cedar Claim

In the State Engineer's report the estimates are un- doubtedly the results obtained after careful investigation of the subject ; but, unfortunately, the quantity of water, grades and size of the sluices, and character of the riffles are not given.

According to Le Conte,t " if the surface of the ob- stacle is constant, the force of running water varies as the square of the velocity, the transporting power of a cur- rent varying as the sixth power of the velocity ; but the power of removing material will vary between the square of the velocity and the sixth power of the velocity."

The transporting power (as used by Le Conte) and the transporting capacity are terms which must not be con- founded. Transporting capacity denotes the amount of ma- terial which running water carries along per unit of time.

The transporting capacity of sluices is generally great- er (comparatively) than that of rivers, on account of the usually heavier grades (from 200 to 300 feet per mile), regularity of cross sections, and character of the bottom and sides of the former.

In sluices where the riffles are blocks a larger amount of material is moved than where rock riffles only are employed. An increase in the grade of a sluice would necessarily increase its carrying capacity.

By the State Engineer, W. H. Hall, State of Cal. tv. Gold Run Ditch and Mining Co. t " Elements of Geology," Jos. Le Conte, pp. 19, ao.

272 The Duty Of The Miner S Inch.

The dirt as it enters the sluice has its lighter portion taken up and carried in suspension by the current, whilst the coarse and heavy material moves along on, and in part above, the riffles, but below the surface of the water. Boulders and rocks move down the sluices with varying velocities and in different directions as they advance, aid- ing in stirring and disintegrating the cement gravel and earthy stuff, which little by little fall to pieces and into par- ticles that, segregated as light material, rise towards the surface of the water. The rocks and boulders travelling over the riffles assist in keeping the material thoroughly agitated in the sluices, where it is alternately changing position from the bottom to the top, until it is finally dis- charged.

The material, wearing down as it advances, is kept from packing by the presence of the rolling rocks which still maintain their solidity. Light, sandy gravel requires very wide and shallow sluices, as it cannot be washed ad- vantageously in deep sluices, unless by a proper mixture of rocks, which permits the use of a greater quantity of water, so that the capacity of the same sluice is increased.

A heavy grade will compensate for a limited supply of water. With an abundant supply of water and material, the capacity of sluices will depend upon :

1st. The character of the material washed ;

2d. The size and minimum grade of the sluices ;

3d. The character of the riffles used.

The statement of some engineers that the transporting power (meaning capacity) of a sluice increases with the third power of its grade is not verified by the compara- tive tests which have been recorded. However, these tests, which give the only reliable data extant, were not made with the same material, so there is still a very im- portant factor undetermined.

The empirical results thus far obtained demonstrate that the transporting capacity of a sluice set on a 2.08 per cent, grade, and that of a sluice on a 4j4 per cent, grade,

The Duty Of The Miner'S Inch. 273

vary as the 1.52 to the 1.87 powers of these grades. How this will agree with the results obtained from properly conducted experiments on increasing from 4 or to 8 or 9 per cent, grades remains to be ascertained. Mr. Hamilton Smith, Jr., considers that under these circum- stances the transporting power (capacity) of the sluice will increase about with the square of the inclination.

Mr. P. M. Randall says that the transporting power (capacity) of water is as the 3.75 power of the velocity.

From official data of the Blue Tent Company of the amounts of light material washed on a 10 per cent, grade, it would appear that the transporting capacity for such material varies as the 1.20 power of the grad.

The time, means, and facilities for the careful and thorough investigation and determination of the duty of the miner's inch have not as yet been afforded to the en- gineers who have been appointed for this purpose. In most cases the amounts of material estimated to have been removed may be considered as mere approximations, as is evidenced by the wide differences in the many esti- mates which are given in the various publications.

In the suit of the State of California vs. the Gold Run Ditch and Mining Company the estimates of the amounts of material washed and remaining, made by the various engineers who had investigated the subject, showed dif- ferences as great as 33 per cent, where the question of size of excavations and cubic contents was alone at issue. The difference arose largely from attempts to reconstruct from insufficient data the former topography of the land mined, no accurate information upon the point being ob- tainable.

The only known attempts at any extended and detailed investigation of the duty of the miner's inch have been made by the North Bloomfield and the La Grange Hy- draulic Mining Companies. The results of the work per- formed at these mines are given in the annexed tabulated statement :

The Duty Of The Miner'S Inch.

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Chapter Xx.

Statistics Of The Costs Of Working And The Yield Of Gravel.

Correct statistics showing the costs, the quantity of material washed, and the corresponding yield of gold are rare and difficult to obtain. In the early days of placer- mining in California the question to be solved by the miner was not what the gravel would yield per cubic yard, and what it would cost to move it, but rather how many ounces of gold-dust he could " pan out " or " rock out between sunrise and sunset. What the miner re- quired was that the daily yield in dust should exceed the cost of living, etc. When it fell below this he moved his camp to other grounds.

The wonderful productiveness of the river bars and shallow placers, attested by the gold bullion and dust shipments, created an extravagance usual to all new and rich mining countries, the baneful effects of which are still felt.

As the richest and most easily worked placers became exhausted the increasing necessity of mining on an exten- sive scale and with ample capital led to the formation of large companies. Then became evident the importance of determining beforehand the amount of gold in the va- rious claims and the costs of working them. This last included various engineering problems, as the best grades, the duty of the inch, etc. In this manner the first data concerning the yield (commonly estimated per cubic yard, but very often, for the sake of convenience, per inch of water) of the auriferous gravels were published. Many

276 Costs Of Working And The Yield Of Gravel,

of these were collected and printed in the reports of the U. S. Commissioner of Mining Statistics, and Prof. Whit- ney has added to them in his " Contributions to American Geology." Detailed investigations have been undertaken of late by the State Engineer of California and also by Lieutenant-Colonel Mendell, Corps of Engineers, U. S. A.

There is now obtainable quite a large amount of sta- tistics in printed form ; but to a great extent these are of no value, partly from their unreliability, partly from their insufficiency of detail. Miners and mining corporations as a rule object to making public anything concerning their property except what is absolutel} necessary, and are apt, when pressed, to give ambiguous information. As it is impossible, after large areas of ground have been washed away, to accurately reconstruct their topog- raphy, all statistics of the cubic contents of excavations derived from surveys made after mining has ceased are unreliable.

The most reliable data are thos6 of the North Bloom- field and the La Grange Hydraulic Companies, both of which hav6 carried on their works in the most intelligent and satisfactory manner.

To better familiarize the reader with the subject of gravel-mining, and thus enable him to form an idea of the amount of water used per cubic yard of dirt moved, and of the corresponding yield and attendant costs, an exhibit of a claim running on an approximately minimum basis — viz., light pressures and smallest practicable grades — has been selected. For this purpose the claims of the La Grange Company have been chosen, as the yield per cubic yard and the grades there used can be considered as nearly the lightest with which an hydraulic claim can yield remun- erative returns.

The annexed tabular statements show in convenient form the data alluded to.* The tables have been care-

In obtaining the data for these ubles I am greatly indebted to the valuable assistance of Mr. Joseph Messerer, superintendent of the La Grange Ditch and Hydraulic Mining Company.

Costs Of Working And The Yield Of Gravel. 2/7

fully arranged, and the data of the yield and disburse- ments are accurate. The apportionment of the material account has in some places been calculated from the gene- ral material account. The measurements of the ground washed were made at each clean-up, and subsequently the entire ground was resurveyed and the work checked.

Table Xlvii.

R/sumd of work done by the La Grange Co. on all its claims June I, 1874, to Sept. 30, 1876.

1*533.728 inches (2,159 cubic feet each) washed 2,275,967 cubic yards of gravel, which yielded 12.026.84 oz. Troy $231,893,

Disbursbmbnts.

Water

Total.

I17.307 62 82.345 70 21,788 35 Tt.24.1 01

Per cubic yard, $0 008

Per ounce metal produced.

$1 43

Labor

Material

Official

Contingent

3,125 80 ' 006 1. 130 41 1 )

Taxes

Total

$136,942 82 $0 060

$1138

Average value of the oz Average yield per cubic

. of metal (gold and silver) produced. .$19 29 yard of gravel 1019

Average amount of grav

el washed per inch, cubic yards i 48

The following tabular statements show the workings of a mine on four per cent, grades, high banks and with great hydrostatic pressure. The advantages of heavy grades and pressure over the minimum La Grange grades are clearly shown by the quantity of material moved, and a comparison of the work and costs will be of interest to those engaged in hydraulic mining (see Table XLVII I.)

278 Costs Of Working And The Yield Of Gravel.

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Costs Of Working And The Yield Of Gravel. 279

TABLE XLIX. Classification of Mines and Mining Expenses,

Class I.— Mine* with Grades to per cent :

Operating expenses 33 to 60 per c gross yield, segregated as follows :

Hanks 20 to 80 feet high ; many cobbles; few boul- ders ; cuts light ; material easily washed ; worth 8 cts. to 16 els. per cubic yard.

cent, of

Labor. 60 per c

Material 16

Water xy,

Explosives, bank powder i

high-grade

Geheral 10

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Banks 50 to 150 feet high ; few boulders ; cuts not hard ; considerable bank blasting ; material worth 20 cts. to a; cts. per cubic yard.

Operating expenses 45 to per cent, of gross yield, segregated :

Labor 42 per ct.

Explosives, bank powder 17

" high-grade, caps

and fuse a

General 9 "

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' Operating expenses 55 to 65 per cent, of gross yield, segregated :

I.abor 54 perct.

Material 13

Water. 15 "

Explosives, bank powder. ... 7 " high-grade, caps

and fuse 3 "

General 8

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f Operating expenses 30 to 40 per cent, of gross yield, segregated :

Labor 54 pcr ct.

Material 11

Water 15

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and fuse 7

General la

NoTB.— This estimate is based on the supposition that each company owns its water. Wages $a 50 per diem.

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Appendix.

Appendix A.

San Francisco, Cal., May 26, 1884. A. J. Bowie, Jr., Esq., Present:

Dear Sir : You will find herewith a statement of the produce of gold in the United States since its discovery in this State in January, 1848, to the close of the fiscal year ending June 30, 1883, prepared by me at your re- quest.

The imperfect methods of collecting and preserving such data in this country are so well known to statisti- cians and others as to scarcely require any apology for the inaccuracies of these estimates or the indulgence of your readers. I. have long been satisfied that the pro- duce of the precious metals in this country, as well as in others, has been considerably exaggerated, and that the tendency to over-estimation is inherent in the methods adopted. My long connection with the mining indus- tries of this coast, however, through metallurgical opera- tions of great magnitude, enables me to eliminate some of the inaccuracies which have crept into published state- ments, and which have been adopted and repeated by subsequent statisticians.

Undoubtedly the most reliable method of determin-

ing the produce of this country in the aggregate is that

based upon the deposits of " domestic gold made at the

several nriints, as stated in the directors* reports, and the

exports of uncoined domestic bullion, as shown by those

282 Appendix.

of commerce and navigation ; though in its distribution both of these reports are necessarily more or less defec- tive in detail, and the latter more particularly contain many palpable errors and omissions.

In order to conform to the data derived from these reports I have stated my estimates in fiscal years instead of calendar years, which are usually adopted by other sta- tisticians. As I only have the mint reports as far back as 1855, I have not the details of foreign gold, old United States gold coin, jewellers* bars, and old plate deposited from 1848 to 1854. I have, therefore, estimated these items for this period at live millions, which I find to be about the excess of the coinage over the domestic " gold deposited, as shown in the Summary tables of the re- port of 1873. I" the navigation reports the uncoined gold exported was not separated from that of gold coin prior to 1855. I have, therefore, estimated the amount for these seven years at $88,479,269, including the $33,479,269 of fine bars made at the Philadelphia mint in 1853 "d 1854 and not accounted for in the coinage.

It may be well here to note also another fact which I think has been generally ignored or overlooked, and that is the large amount of private coinage made here by the old United States Assay Office and other coiners from 1849 to 1855, which was almost our only currency on this coast during that period. From the best information I can obtain on this point there could not have been much less than $60,000,000 thus coined for the seven years em- braced. Much of this, however, was exported as soon as made, but there could not have been much less than $25,. 000,000 or $30,000,000 in circulation when the mint here went into operation, April i, 1854. It then disappeared very rapidly, and I have eliminated the amount entirely by deducting it from the apparent produce of the years 1854, 1855, and 1856, and have added it to that of pre- vious years, distributing it to the best of my judgment. In addition to this there should be added to the ascer-

Appendix. 283

tained prcnluce of these earlier years an appreciable amount for what was taken out of the country in private hands. In consequence of the high rates charged by steamers in those days on the export of treasure (5 per cent, and primage), a very large amount was thus taken from the country. For several years the deposits at the Eastern mints exceeded by ten or fifteen millions annually the entire exports from this city, as shown by the Custom- House records. As every steamer carried from five hun- dred to one thousand passengers, no inconsiderable amount must have gone abroad in the same way. At a later pe- riod, say from 1862 to 1872, more or less gold was thus taken out of the country by returning Chinese, but never to the extent some have supposed. Nearly the whole of this gold was obtained from the establishment of which I was the manager, and I therefore speak advisedly.

It may be well to explain here also the causes of the marked decline in the produce of California gold in cer- tain years. That of 1857 was largely due to the great excitement and resulting exodus from our mining dis- tricts incident to the Frazer River discoveries in British Columbia. The rapid decline which is noticeable from about 1863 was due, in part, to the two excessively dry years of 1862-63 and 1863-64. but to a still greater ex- tent to the great loss of mining population resulting from the silver discoveries in Nevada — not less than from fif- teen to twenty thousand of our population leaving for that State within a few years following these discoveries. The increase in California gold noticeable from about 1878 is mainly due to the produce of the Standard and other mines in the Bodie district.

While stating the produce of California at about $1,- 100,000,000, my belief is that it does not exceed $1,050,- 000,000, if so much. I can trace to this city at least $25,000,000 of uncoined foreign bullion, principally from British Columbia, which has not been accounted for by deposits at the mint or re-exports. I personally know

284 Appendix.

that much the larger portion of this gold went into the private refinery, and subsequently into the mint as " fine gold from that establishment. Again, the directors* re- ports do not designate localities at the mint here prior to 1862, and up to that date all domestic gold has been cre dited to California. At the Philadelphia mint the first receipts of gold from Oregon were in 1853. As all gold from that State was first shipped to this city, doubtless large amounts went into the mint here, and that which did not was exported East under the stamp of some San Francisco assayer and there credited to California. From about 1864, and for a number of years subsequent thereto, heavy shipments also set in from Idaho and Montana via Oregon, ranging for quite a period from five to eight mil- lions per annum. From 1862 to 1883 nearly $40,000,000 of domestic gold is credited at the mint here to " other States and Territories ; and as the private refinery and the other assay offices did a much larger business in the aggregate than the mint, it is fair to presume that at least an equal amount of this gold went into these establish- ments, and its identity was thus destroyed before it reached the mints. I therefore consider it a very low estimate to say $25,000,000 of this gold has been credited to California through fine gold from private refineries and assayers* imported bars. This, however, does not affect the accuracy of the statement so far as the aggregate re- sult is concerned, but only its distribution.

In the analysis I have been compelled to make of the exports of uncoined domestic treasure, a suspicion I have long entertained has been fully confirmed, and that is that a very considerable amount of the gold contained in the produce of our silver-mines has been exported under the silver valuation. This is clearly evident from the fact that in quite a number of years the gold so contained, and not accounted for by gold parted " " from silver " at the mints and private refineries, exceeds considerably the en- tire exports of uncoined domestic gold.

Appendix. 285

In the summary statement which here follows it will be observed that I have stated the amount of gold con- sumed in the arts, lor the period considered, at $50,000,000. I am satisfied that this is in excess of the facts. I have on several occasions made a partial investigation of this ques- tion for my own information, and the results have always impressed me with the idea that the popular impressions upon this subject were very much exaggerated. Native gold is absolutely unfitted for the arts without refining, and, with the exception of a small amount of quartz jewel- ry and a few curiously shaped specimens of placer gold, is not employed for such purposes to any appreciable ex- tent. The amount so employed is, therefore, almost fully accounted for by the deposits at the various mints, and should be considered with reference to the entire stock of gold in the world, and not confined to the current annual produce. The Director of the Mint, in his report of 1879, gives the results of his investigations of this question, as shown by the operations of the United States Assay Of- fice at New York for the seven years from 1873 to 1879, both inclusive. According to this statement it would ap- pear that for this period $24,780,884, or $3,540,000 per an- num, had been obtained from this office for manufactur- ing purposes. By analyzing the operations of that in- stitution, however, it will appear that not much more than $1,500,000 per annum is chargeable to the current annual produce of domestic gold. Succinctly stated, these operations were as follows :

Gold of domestic production deposited, $48,477,238 ; fine gold sent to Philadelphia for coinage, $59,920,443 (ex- cess, $11,443,205) ; receipts of foreign gold and United States gold coins for recoinage, $37,322,340 ; jewellers* bars, old plate, etc., $3,690,834. By deducting this latter sum we have left $21,090,050 as the amount of new gold going into the arts. Apportioning this to the total re- ceipts, we have $1 1,916,000, or $1,702,000 per annum, to be charged to domestic gold, and $9,174,000 to be charged

286 Appendix.

to gold from other sources. But for the same period the receipts of jewellers* bars, etc., at the Philadelphia mint exceeded all the fine bars made by that institution by some $1,351,143, or $193,020 per annum; and the opera- tions of these two establishments are so intimately con- nected that they should be considered together. De- ducting this excess leaves only $1,500,000 per annum to be charged against the current annual produce. The business has greatly increased within the past few years, but I am satisfied that the average of these seven years is considerably above that of the whole period under con- sideration. In this city, where the gold -thus employed is obtained entirely from the private refinery, it has not, until within a year or two past, exceeded $25,000 per an- num. But it has now increased to from $120,000 to $150,000.

I should explain, perhaps, that in the statement of gold parted from silver at the mints I have added to the amount as shown by the director s summary statement the amount credited at the Carson mint to " Nevada,** as nearly the whole amount so credited evidently came from Comstock bullion.

By deducting from the aggregate deposits, as stated in this summary, the deposits prior to 1848 ($12,808,771) and the unparted bars made at the other assay offices and not redeposited at New York or Philadelphia, we have as the whole amount of domestic gold deposited at the mints and New York Assay Office since 1848, $1,179,824,781.

To wit : From California $723,043,793

" Other States &

Territories . . 171 ,482,2 1 8 " Parted from sil- ver bullion. . 39,584,350 " Private Refine- ries, fine gold 245,714,420

$i,i79824,78i

Appendix. 287

Amount brought forward $1,179,824,781

Foreign gold, U. S. gold coin, jewellers' bars, etc 35i735237

Total deposits from all sources $1,531,560,018

Total gold coinage $1,264,623,632

Uncoined bullion on hand June

30, 1883, estimated 65,000,000

Mint deposits consumed in

arts 50,000,000

Mint deposits to be accounted

for in exports 1 5 1,936,386

$1,53560,018

The operations of the private refineries here from 1865 to 1883 have amounted to $265,886,266, of which $243,- 597,532 was deposited in the mint and $22,288,734 sold for export. Of the whole amount received $191,992,266 was in gold dust and bars, and $73,894,000 was parted from silver. I have distributed these amounts to the best of my judgment. Making the r6sum6 in another form, we have :

Total gold coined, as above $1,264,623,632

" uncoined gold exported 463,943,938

uncoined gold on hand and consumed

in arts 11 5,000,000

$1,843,567,570 Less foreign gold, etc., as above 35i735,237

Total produce of domestic gold $1,491,832,333

My estimates as per statement 1,469,753,1 17

Difiference $22,079,2 16

This difference is due to the foreign gold credited to domestic sources in mint reports, through fine gold from private refineries, but which I have eliminated. Very truly yours, etc.,

[Signed] Louis A. Garnett.

Appendix.

Produce of Gold in the United States from its discovery in Cali- fornia yanuary 1848, to yune 30, 1883. Stated in FisccU ' Years,

Years.

Gold produced

in State of California.

Gold pro- duced in other States and Territories.

Total produce of Gold-Mines.

Gold con- tained in Sil- ver Produce.

Grand Total

Produce from

all sources.

::.

x86o 186a

5866

x88o

-1881

Totals..

$245,301 10,151,360

$851,274 927,684

$1,096,575 11.079.044

$50,000

800,000

2,150,000

4,350,000

S.300,000

$1,096,575 1 1.07P.044

10,396,661

1,778,958

12.175,619

12,175.619

41,273,106 75,938,232 81,294,700 67,613,487 69.431.931

603,380 712,363 508,564 351,627

4 ',938,323 76,540,612 82,006,963 68,i2a,o5i 69.685.558

41,938,333 76,540,612 82.006,963 68,122,051 69,685.558

335,553.456

2,740,051

338.293,507

338,393.507

55.485,395 57.509,411 43,628,173 46,591,140 45,846,s99

3>2.364 369,031 336,oa8 366,957

55,797,759 57,878,44a 43,77 ',225 46,977,168 46,213,556

55,797,759 57,878,442 43,771,225 46,977,168 46,313,556

249,060,717

577,433

250,638, 1 ;o

250.638,150

44,095, X63 41,884,995 38,854,668 23,501,736 34,071,433

875,878 2,831,895 3,989,2x0 7,474,808 8,372,1x5

44,971,041 44,716,80 42,843,873 30,976.544 32,443. S38

45,021,041

45,5x6,890 44.993.878 35,326.544 37,743,538

173,407.985

91,543,906

i95.95£9i

12,650,000

208,601,891

17,930,858 17,133,867 18,265,452 17.555,867 18,229,044

9,920,244 12,086,941 13,169,117 7,943,116 7,607,698

27,851,102 29,210,808 31,434,569 25,497,983 25.836,742

'5,500,000 4,650,000 5,700,000 4,000,000 3,550,000

37,134.569 29,497,983 29,386,742

50,726,116

139.831.204

23.400,000

163,231,204

17,458,133 17,477,885 15,482,194 15,019,210 17,264,836

7,907,569 7,813,419 6,975,843 7,313,768 6,863,013

25.365,702 25,291,304 22.458,037 22,232,978 24,127,848

3,700,000 5,500,000 6,900,000 12,000,000 11.500,000

29,065,702 30,791,304 9.358,o37 34,232,978 35,627,848

82,702,258

36,773.611

119,475,869

39,600.000

159,075.860

16,876,009 15,610,723 16,501,268 18,839,141 19,626,654

5,572,299

9,755,213 10,431,948

22,448,308 21,121,995 25,363,962 28,594,354 30,048,602

13,800,000 18,500,000 18,300,000 19,000,000 9.000.000

36,248.308 39,621,995 43,663,962 47,594,354 39,048,602

87,453.795

40,123,426

127,577.221

78,600,000

206,177.921

20,030,761 19,233,155 17,146,416 17,256,873

9,909,033 10,139,136 8,468,141 8,586,141

29,239,794 29,362,291 25,614,557 25,843,014

6,000,000 6,000,000 5,000,000 4,500,000

35,239,794 35.362,291 30,614,557 30,343.014

73,657,205

36,402,451

110.059,656

21,500,000

1 31.550.656

$1,100,337,165

$193,665,952

$1,294,003,117

$175,750,000

$',469.753,i7

Appendix.

Appendix B.

Fineness Of Placer Gold.

Mine.

Locality.

Fineness.

Remarks.

Alpha

Nevada Co.

Plumas Co.

Placer Co.

Butte Co.

Sierra Co.

tt

tt tt

tt tt tt tt

tt ((

ti tt

tt tt

tt tt

Stanislaus Co. tt ft

tt tt

tt tt

tt tt

ft ti

.940 to .950

.925 to .930 .930 to .950

.925 to .950

.835 to .871 .774 to .800

.800 to .961

.958 to .968

.942 to .965

.835 to .890 .920 to .930 .930 to .934

.926 to 936.

.916 to .918 .873 to .899 .926 to .954 .936 to .951 .895 to .945 .935 to .950 .934 to .943

j Gold flattened in scales.

Gold coarse. Gold fine.

j Gold coarse on bed-rock.

Gold coarse.

j Gold well rounded and smooth. ( Gold from blue and red gravel ( respectively. Gold from upper gravel sometimes reaches .980 fine.

Bed of the creek. Gold coarse like shot.

j Gold coarse, in ( flakes.

American Hill

Brush Creek

Manzanita

French Corral

Badger Hill

MumfordHiU

Michigan Bluff.

Cariboo Diggings

Cement Hill Claims . . Cedar Claim No. 2... .

Cherokee Flat

Cafton Creek

Caflon Creek

Goodyear's Bar

North Yuba

Eureka Mines (near )

Downieville) f

Mugginsville

Fir Cap

Monte Christo

Craycroft's

Gold Lake

North Fork of North Yuba '

South Fork of North Yuba

Hog Cafton

Bald Mountain

Tim Crow Cafton

Niagara Consolidated. Kelley

French Hill

Light Claim

Chesnau

Johnson

Sicard

Gold very fine and scaly on bed-rock. Out of 650 diamonds found in this deposit only one had as great a value as $350.

290 Appendix.

FINENESS OF PLACER 001S>— Continued.

Mine.

Camptonville

Galena Hill

Young Hill

Railroad Hill

Depot Hill

Indian Hill

Oaks Valley )

Dad's Gulch J

High Point

Oregon Creek. ..

Pike City

Brush Creek Co.

Locality.

Fineness.

Yuba Co.

.930 to .935

.890 to .880

Renuirlu.

According to King in " U. S. Geol. Survey Report/* Second Annual Report, 1880-81, p. 379, the fineness of specimens of California gold as determined by him was as follows :

No. of Mines examined.

Locality.

Fineness.

Butte Co. Calaveras Co. Del Norte Co. El Dorado Co. Humboldt Co. Placer Co. Plumas Co. Shasta Co. Siskiyou Co. Stanislaus Co. Trinity Co.

.900 to .970 .850 to .960 .875 to .950

.726 to .940 .784 to .960 .846 to .936

.749 to .950

.875 to .927

Total ...51

.726 to .980

Eighty specimens averaged .883.6 fine (p. 382). Dana's " Mineralogy says : " California gold fineness averages .875 to .885. Average, .880.**

Appendix. 291

King places the average fineness of gold from the dif- ferent parts of the United States as follows :

California 883.6

Colorado 820.5

Dakota 923. 5

Georgia 922.8

Idaho 780.6

Montana 895-1

Oregon 872.7

All the United States 876

Note. — The larger portion of this table was compiled from Whitney's Auriferous Gravels. '

Index.

Abbey, R., on yield of French Hill Claim, Stanislaus Co., Cal., table li.

Absorption, 91, 130, 132, 138.

Abutments for dams, 97.

Abyssinia, 16.

Aconcagua, Chili, 27.

Adkins, Consul, cited, 19.

Africa, 16. 17.

Air-valves — see Valves,

Aji River, India, 17.

Aktolik River and Valley, Siberia, 23, table Hi.

Alatri, Italy, 158.

Alder Gulch, Montana, 40.

Allison Ranch Mine, Nevada Co., Cal. ,

Altai, Siberia, 20, 22, table Hi.

Alvarez, Expedition to Gulf of Cali- fornia, 42.

Amador Canal Company, Cal. , tables xiii., XV., 270.

Amador County, Cal., 66.

Amalgam, 205, 249, 258, 266, tables xlii.-xlvi.

American HHl, Nevada Co., Cal., 49.

American Institute of Mining Engi- neers, Transactions of, 20, 70, table Hi.

American Mine, Nevada Co., Cal., 180, 234, 270, table 1.

American River, Cal., 63, 65, 77, 95, 238, 239, 268, 269.

American Society of Civil Engineers, Transactions of , 119, 120, 174, 176,

Amgun River, Siberia, 25.

Amur River, Siberia, 20, 25, table Hi.

Ancient aUuvial gold deposits, Most, 33, 67.

Ancient river channels — see River channels.

Angles of repose and friction of em- bankment materials, 102.

Annales des Mines," 70.

Appalachian gold-fields, 39.

Appendix A, 281.

Appendix B, 289.

Aquileia, Italy, 15.

Ararat, Australia, 31, table Hi.

Area of available mining ground in California, 76, 77.

Area of wrought-iron pipes, 161.

Ariege River, France, 16.

Arrow, New Zealand, 36.

Asia Minor, 15.

Asiatic Islands, 18.

Asphaltum in California, 72.

Asphaltum coating for iron pipes, 167.

Atchinsk, Siberia, 20, 24, table Hi.

Atrato River, U. S. of Colombia, 29.

Attaki, Egypt, 16.

Attwood, Melville, quoted, 203.

Auriferous slate formation in California,

Australasia, 30-37. Australia, 83, 205, table Hi. Available mining ground in California, . 76, 77.

Ayacucho, Department of, Peru, 28. Ayakta River, Siberia, 24.

Babb Tunnel, Timbuctoo, Yuba Co.,

Cal., 232. Bache, Mt., Santa Clara Co., Cal., 60.

Index.

Back Creek, New South Wales, 33. Badger Hill, Nevada Co., Cal., 71, 234. Baikal Lake, Siberia, 24. Bald Mountain, Sierra Co., Cal., 84,

table li. Ballarat, Victoria, Australia, 31, table

Banks of ditches. Slope of, 138. Bar-mining, 47, 48, 51, 78, 79, 80. Barguzinsk, Siberia, 20, 24. Barossa, South Australia, 34. Barrington, New South Wales, 33. Basalt overflow, 33, 34, 68. Baskir District, Siberia, 21. Batea, 202.

Bath, Placer Co., Cal , 71. Bathurst District, New South Wales,

32, table lii. Bazin, cited, 127, 129. Beach-mining, 36, 78, 79. Bean's Hill, Plumas Co., Cal., table li. Bear River, Cal., 77 95, 114, 140,

239, 269. Bed-rock Claim, Nevada Co., Cal.,

Bed-rock riffles, 227. Bed-rock Tunnel, Sweetland, Nevada

Co., Cal., 234. Beechworth District, Victoria, Aus- tralia, 31, 353, table lii. Begert, Father, map of California, 45. Belgaum, India, 17. Bellows. W. H., flume, 150. Belt of the Coast Ranges of California,

Belt of the Great Valley of California,

53, 54, 62, 66. Belt of the Sierra Nevada of California,

53. 54, 63, 64. Belts, Geological, of California, 53. Bench claims, 78. Benches, Washing in, 246. Bendigo, Victoria, Australia, 34. Bendigo, New Zealand, 36. Bennet Claim, Calaveras Co., Cal.,

table li.

Berenice, Egypt, 16.

Beresowska, Siberia, table lii.

Beriozofka Mine, Siberia, 23.

Betmangla, India, 18.

Big Cafton Creek, Nevada Co., Cal,,

103, tables v., vL Bituminous slate formation in Califor- nia, 59. Black Hills, Dakota, 146. Black sands, 79-88. Blake, W. P., cited, 16, 27. Blasting, 206-214. Block riffles, 224, 234, 357, 259, 271,

Blow-offs, 166. Blue gravel, 87. Blue Gravel Mine, Yuba Co., Cal.,

232, table li. Blue Lead Mine, Nevada Co., Cal.,

table li. Blue Point Mine, Yuba Co., Cal.. 207,

232, table 1. Blue Tent Mine, Nevada Co., Cal.,

95, table xiii., 210, 273, table li. Bogoliubsky, cited, 21, 25. Bogoslofsk, Siberia, 21, table lii. Boise Basin, Idaho, 39. Bolivia, 27. Bombay, India, 17. Bonanza Mine, Gold Run, Placer Co.,

Cal., 180. Booming, 79, 81. Borneo, 18.

Boston Tunnel, Nevada Co., Cal., 334. Bouyer Ditch, 138, 140, table xiii. Bowman, A., on yield of gravel claims

in Yuba Co., Cal., table li. Bowman reservoir and dam, 93, 95,

loi, 103-112, tables v., vi. Box, Distributing — see GtUes, Box, Pressure — see Pressure box Bracket flume, 150. Brazil, 25, 302. British Columbia, 37, 52. Broad and shallow ditches, 137. Browne, J. Ross, cited, 46, 66.

Index.

Browne, Ross £., cited, 193. Browne, Mt., New Sooth Wales, 32. Brown's Bar, El Dorado Co., Cal., 51. Buccaneers' search for gold, 39. Buckets for hurdy-gurdy wheels, 194-

Buena Vista, Amador Co., Cal., 370. BuUock-Head Creek, New South

Wales, 33. Burehya River, Siberia, 35. Burke Cooaty North Carolina, 39. Buruma Rmr Siberia, 24. Butte County, CaL, 49, 65, 66, 103,

141, 143, 150, tables xiii., xv., 172. Butte Creek, Butte Co., Cal., 239, 269.

Cabarrus County, North Carolina, 39.

Cabrera, Rodriguez, 43.

Cajon Pass, San Bernardino Co., CaL,

Calaveras County, Cal., 66, table li. Calaveras River Cal., 77, 238. 270. California, Available area of pay

gravel, 76, 77. California, Dry season in, 90. California, Geology and topography of,

California, Gold product of, 42.

California, History of placer-mining in, 43-52.

California, Navigable waters affected by hydraulic mining, 238.

California Mining Company, El Do- rado Co., Cal., 95, Uble xiii.

Camanche, Calaveras Co., Cal., 270.

Campo Seco, Calaveras Co., Cal., 270.

Cana, U. S. of Colombia, 29.

Canada, 37, table Hi.

Canvas hose, 49.

Capital invested in hydraulic mines, 52.

Caratal, Venezuela, 28.

Caravaya, Peru, 27.

Carboniferous limestones in California,

Caren, Chili, 27.

Cariboo, British Columbia, 38.

Carpentaria, Gulf of, Australia, 34. Cascade Ditch, Nevada Co., Cal.,

table xiii. Cassiar, British Columbia, 38. Castilla del Oro, U. S. of Colombia,

Castlemaine, District of, Victoria, Aus- tralia, table lii. Catchment area, 93, 103, 105, table vi.,

Caving banks, 245, 246. Cedar Claim, Nevada Co., Cal., 271. Cement deposits and claims, 32, 35,

36, 256, 257. Cemetery Lead, Victoria, Australia,

Cervo del Espiritu Santo, U. S. of

Colombia, 29. Ceylon, Island of, 18. Chalk Bluff Ditch, Nevada Co., Cal.,

140, table xiii. Chaluma River, Peru, 28. Charoparan District, India, 18. Champlain period in California, 80. Channels, Open — see Optn channels. Charging sluices, 244. Charleston, New Zealand, 36. Charter's Towers, Queensland, 34. Chaudire River, Canada, 37. Cherokee, Butte Co., Cal., 49, tables

xiii., XV., 269. Chesnau Claim, Stanislaus Co., Cal.,

72, 241, 274, tables xliv., 1. Chezy, cited, 128, 129. Chia-t'i-kou Valley, China, 19. Chico Creek, Butte Co., Cal., 236. Chile Gulch Mine, Calaveras Co.,

Cal., 270. Chili, 26, 27. Chilian, Chili, 27. China, 19, 20. China Ditch, Yuba Co., Cal., 138. 140,

table xiii. Chirimba Valley, Siberia, 23. Choco, U. S. of Colombia, 29. Christy, S. B., cited, 80.

Index.

Cinnabar in California, 58.

Ciudad Bolivar, Venezuela, 28.

Clark's Ditch, Calaveras Co., Cal.,

Classification of gravel deposits, 78.

Classification of mines and mining ex- penses, 279.

Classification of mining operations, 78.

Cleaning up, 247, 248.

Clear Creek, Shasta Co., Cal., 46.

Clear Lake, California, 53, 56, 58, 60.

Clough's Gully, New South Wales, 34,

Clutha River, New Zealand, 36. Coal in California, 58. Coal measures. Auriferous, New South

Wales, 34, 67. Coal tar, coating for pipes, 167, 168. Coast Ranges, California, Belt of, 53-

Coating iron pipes, 167, 168. Coefficients of discharge of water

through ditches, 131-134. Coefficients of discharge of water

through rectangular orifices, 123. Coefficients for roughness, 129. Coloma, El Dorado Co.. Cal., 46. Colombia, United States of, 29. Colorado River, 45. Colorado, State of, 41, 81. Columbia Hill, Nevada Co., Cal., 71,

124, 234, table I. Concepcion, U. S. of Colombia, 29. Concow reservoir, Butte Co., Cal.,

Cook Bros'. Ditch, Calaveras Co., Cal.,

Copiapo, Chili, 26. Copper veins in California, 61. Coquimbo, Chili, 27. Cortez, Conquest of Mexico, 31. Cossack District, Siberia, 21. Cost of dams, 103, 109, 112.

ditches, 139-142, 153-156. " electric light, 246. flumes, 153-156.

Cost of pipes, 169, 170.

prospecting work, 88.

reservoirs, 93.

sluices, 232-235.

tunnels, 218, 233, 234.

undercurrents, 232.

working, 275-277, tables xlii.- Cosumnes River, Cal.. 77, 238, 270. CotU. B. V , cited, 70. Coy Diggings, Victoria, Australia, 32. Coyote Hill Ditch, Nevada Co.,Cal.,47. Coxe, E. B., cited, 119. Cradle— see Rocker, Craig. R. R., on discharge pipes, 49,

50, 180, 181. Crawford, J. J., cited, 124, table 1. Crawford's Claim, El Dorado Co.,

Cal., table 1. Cretaceous strata in California, 54, 58,

59, 64, 66. Creviceing, 248.

Crooked Lake, Nevada Co., Cal., 104. Crosiner, cited, 27. Curves of flumes, 144. Curves of sluices, 218, 227-231.

Dahlonega, Georgia, 39.

Dakota Territory, 41, 146.

Dams, 90-118, 239.

Dams, Wing, 48.

Dana, Jas. D., cited, 45, 80.

D*Arcy, cited, 129.

Dardanelles and Oro Mine, Placer Co.,

Cal., 208. 209, table li. Darfur, Egypt, 17.

Dargo District, Victoria, Australia, 32. Darien, Isthmus of, 29. Davidson County, N. Carolina, 39. Dris — see Tailings, Debris dams, 1 12-1 18, 239, 240. D6bris in streams, 238-240. Deep-placer mines, 48, 78, 82. Deep tunnels. First, in California, 51* Deer Creek Tunnel, Yuba Co., Cal.,

Index,

I>eer Lodge County, Montana, 40.

Deflector, 50, 183, 184.

Delaney Claim, Stanislaus Co., Cal.,

228, 265, table 1. Depressions, Rich pay in, 72. Derricks, 185.

Devonian deposits in Canada, 37. Dharwar, India, 17. Diablo, Mount, Cal., 56, 58, 59, 60. Dibulla River, U. S. of Colombia, 29. Dictator, Hoskins', 50, 182. Diodorus cited, 16. Discharge pipe — see Nozzle, Discovery of gold in California by

Marshall, 46. Distributing box — see Gate, Distributing pipe, 158. Distributing reservoirs, 93. Distribution of gold in gravel deposits,

Distribution of gold in sluices, 232,

252-259, 260-262. Ditches, 47, 130, I35-I57i table xiii. Ditin, Siberia, table Hi. Diubkosh Valley, Siberia, table lii. Dogtown, Calaveras Co., Cal., 270. Do&a Ana County, New Mexico, 40. Donner Pass, Nevada Co., Cal., 64. Dormentez, Castillo, 43. Dougherty Ditch, Calaveras Co., Cal.,

Douro River, Portugal, 16. Downieville, Sierra Co., Cal., 47. Drainage of the Great Valley of Cali- fornia, 62. Drake, Sir Francis, 43. Dredging machines, 36. Driffield River, South Australia, 35. Drift-mines, 51, 71, 72, 78, 82-84. Drifts, Prospect, 83, 87, 88. Drybread Diggings, New Zealand, 36. Dry Creek— see TabU Mountain Creek. Dry Creek, Amador Co., Cal., 270. Dry Creek No. 2, Cal., 239, 269. Dry Creek Claim, Shasta Co., Cal.,

Uble li.

Dry season in California, go.

Dry-stone dams, loi, 103.

Dry-washing, 79.

Dump. 86, 240-243.

Dutch Flat, Placer Co.. Cai., 140,

table xiii., 239, 268, 271. Duty of the miner's inch, 268-274,

277, 278, tables xl.-xlvi.

Earthen dams, 99.

Earthenware pipes, 159.

Echunga District, South Australia, 35.

Eckart, W. R., cited, 122.

Egypt, 16, 17.

Eight-Mile Diggings, New South

Wales, 33. Eisenbeck Claim. Nevada Co., Cal.,

263, 264. Ekaterinburg. Siberia, 21. Elbows for pipes, 165. £1 Dorado Company's Ditch, £1 Do- rado Co., Cal , 138, table xiii. El Dorado County, Cal., 63, 124,

tables 1., li. El Dorado Reservoir, El Dorado Co.,

Cal., 95. Electricity, Firing by, 213, 214. Electric light, 246. Elevator, Hydraulic, 36. Embankment materials and slope, 102. Empire Claim, Nevada Co., Cal.,

table li. Empire Hill, Yuba Co., Cal., table li. Empire Mill, Nevada Co., Cal., 190. Empire Reservoir, Nevada Co., Cal., 94. England, 92. English Dam and Reservoir, Nevada

Co., Cal., 93, 95, loi. English Tunnel, Badger Hill, Nevada

Co., Cal., 234. Enterprise Mine, Nevada Co., Cal.,

208, 234, table li. Erosion of material in running water,

236, 272. Ethiopia, 16. Eucumbene River, N. South Wales, 33.

Index.

Eureka Lake and Yaba Canal Com- xiii., 334.

Euxine Sea, Russia, 15.

EvaponUion, 91, 135, 143.

Excavating ditdies, 137, 154-156.

EjEcdsior Ditdi, Yuba Co., Cal., 138,

Excelsior Reservoir, Yuba Co. , CaL , 94.

Explosives, 154, 3io, 213. 233, 334, table xliii. t

Fale's Hill, Plumas Co., Cal., table I.

Fall Creek Reservoir and Dam, Ne- vada Co., Cal., 104.

Fanning, J. T., cited, 96, 100, 102,

Farrell Tunnel, Columbia Hill, Ne- vada Co., Cal., 234.

Faucherie Reservoir and Dam, Nevada Co., Cal., 93, 95, 104.

Feather River, Cal., 47, 63, 77, 95, 238, 239, 269.

Feed pipe, 158, 178-180.

Fifteen-Mile Diggings, New South Wales, 33.

Filling pipes, 168, 178.

Fineness of gold from California mines,

Firing of mines, 213, 214.

Fisher's Hydraulic Chief or Knuckle- joint, 50, 181.

Flat deposits, 78.

Flow of water in open channels, 119,

Flow of water through circular pipes,

Floyd County, Virginia, 39.

Flumes, 135-157, 218.

Fomiha River, Siberia, 22.

Forbes, James Alexander, 45.

Forbes, J. R., cited, 205.

Fordyce Reservoir and Dam, Nevada Co., Cal., 95, loi.

Forest Hill, Placer Co., Cal., 51, 71. 208, table li.

Formosa, Islaaol, it.

Formula for diMfasjof water over

weirs, 120. Formula for flow of water in canal,

Kutter's, 129. Formula for flow of water throu| cir- cular pipes, 178. Formula for flow of water thfoq

ditches in California, 133. Formula for thickness of iron for pipMi

table XV. Formula for velocity of hurdy-gpidy

wheels, 195, 196. Fort Hall, Idaho, 40. Fort Tejon, Kern Co., Cl.. 53. 55.

Fossils and fossil wood in California,

Foster, C. Le Neve, cited, 28. Foundation for dams, 94. France, 16, 92. Francis, J. B., cited, 119. Franklin Mine, Nevada Co., Cal., 271. Frazer River, British Columbia, 38, 52. Fredenburr wheel, 191. French Corral, Nevada Co., Cal., table

Xv., 190, 226, 232, 233, 234, 256-

258, 261, 264, tables 1., li. French Hill, Stanislaus Co., Cal., 72.

242, 274, tables xlii., I., li. French Reservoir, Nevada Co., Cal., 93. Fresno County, Cal., 65. Friction of embankment materials,

Fteley and Steams, cited, 1 19, 120.

Gabriel Gully, New Zealand, 36. Gale, J. M., cited, table xxii. Gardner's Point, Plumas Co., Cal.,

252, 267, uble li. Garhwal River, India, 18. Gamett, Louis A., 281-287. Gates for pipes. 158, 178. Gates Waste, for ditches, 133, 136. Gates, Waste, for flumes, 14s, 154. Gauge for reservoirs, 92.

Index.

Gavilan Mountains, Cal., 56, 60.

Geerts, Dr., cited, 19.

Geological formation at La Grange,

Stanislaus Co., Cal., 68. Geology of California. 53-69. Georgia, State of, 39. Giant, Hydraulic and Little, 50, 182,

Gilbert River, Canada, 37. Glacial drifts containing gold, 37. Glacial period in California, 80. Glen Beatson Ditch, Butte Co., Cal.,

Globe Monitor, 50, 180, 181. Gloucester, New South Wales, 33. Gmelin, cited, 30. Gobi, China, 18, Godfrey, J. H., cited, 20. Gold distribution in gravel deposits,

Gold distribution in sluices, 232, 252,

259, 260-262. Gold, Fineness of, 289--291.

Loss of, 263-267.

" pan, 202.

' product — see Product of gold,

" quartz in veins in California, 48, 61, 65. Gold Bluff, Klamath Co., Cal., 48, 79. Gold Creek, Montana, 40. Gold Lake, Sierra Co., Cal., 47. Gold Run, Placer Co., Cal.. 208, 271,

273, table 1. Gomez, Admiral, 43. Goochland County, Virginia, 39. Goodyear, W. A., cited, table li. Goose Neck, 50, 180. Gopher Hill, Nevada Co., Cal., Uble li. Gorbilka River, Siberia, 24. Grades of ditches, 137-142, 156, table

Grades of flumes, 143, table xiii. Grades of Sacramento and San Joaquin

Rivers, 62. Grades of sluices, 218, 227-231, 259,

266, 274, 277, 278, tables xlii.-xlix.

Grades of tunnels, 232, 334.

Granite in California, 54, 56, 57, 60, 64,65.

Grant County, New Mexico, 40.

Grass Flat, Plumas Co., Cal., 218.

Grass-roots, Gold in the, 71.

Grass Valley, Nevada Co., Oal., 191.

Gravel, Minimum pay in, 76.

Great Belts of California, 53.

Great Pit River, Siberia, 23.

Great quartz vein of California, 65.

Great Valley of California, 53, 54,62,66.

Great Western Mine, Victoria, Aus- tralia, 31.

Green Flat, Plumas Co.. Cal., table L

Green Mountains, New England, 39.

Griffis, cited, 20.

Grimm, J., cited, 70.

Grizzly Hill, Nevada Co., Cal., 71.

Ground sluices, 247.

Ground-sluicing, 32, 33, 35, 37, 79, 81.

Guasco, Chili, 27.

Guayana, State of. South America, 28.

Guilford County, North Carolina, 39.

Guinea, Africa, 17.

Gulch diggings, 51, 78.

Gulf of Carpentaria, Australia, 34.

Gympie District, Queensland, Atutrgr lia, 34*

Hagen, cited, 129.

Hague, J. D., cited, 20. 77, 93, table

xiii., 234, table li. Hakluyt's account of the voyi of

Sir Francis Drake, 43. Hala Mountains, China, 19. Hall. W. H.— see State Enginter. Harcourt. Vernon, cited, 92. Harriman and Taylor Mines, Placer

Co, Cal., 208. Hartt, C. F., cited, 26, 70. Hauraki Gulf, New Zealand, 36. Hays, Sir Hector, cited, 20. Hedwick's Claim, Calaveras Co., Cal.,

table li. Helps, cited, 30.

Index.

Hendel, Chas., on yield of certain gravel deposits at La Porte. Plumas Co., Cal., table li.

Hendricks Ditch, Butte Co., Cal., 138. 141, table xiii.

Herodotus, cited, 15, 17.

Higham, Thos., cited, 119.

Hill Claims, 78.

Hill Top Mine, Calaveras Co., Cal.,

77, 270. History of gold-washing, 15-41. History of placer-mining in California,

Hiuen-thsang, cited, 18. Holt, H. F., cited, 19. Hopoot&, China, 19. Hose, Canvas and rawhide, 49. Hoskins, R., on discharge pipes, 50,

182, 184. Huanca-huanca River, Peru, 2?. Humboldt, Alexander von, cited, 18,25. Humbug Caflon, Nevada Co., Cal.,

Humphreys and Abbot, cited, 119,

127, 128. Hu-Nan, Province of, China, 19. Hunt, T. Sterry. cited, 88. Hurdy-gurdy wheels, 185-202. Hydraulic Chief or Knuckle-joint, 50,

Hydraulic elevator, 36. Hydrauc Giaut 183. Hydraulicking — see Washing, Hydraulic mining, definition, 84. Hydraulic mining versus drift-mining,

Iburi, Province of, Japan, table Hi. Idaho Mine, Nevada Co., Cal., 190. Idaho Territory, 39, 52, 81. Ignition, Simultaneous, of mines, 222. Impact wheels — see Hurdy-gurdy, Inch, Miner's, 1 21-134, 268-274. India, 17, 94.

Indiana Hill, Placer Co., Cal., 71, table li.

Indian Archipelago, 18. Indications of gold in gravel, 87. Inverted siphons — see Siphon, Investigation, Preliminary, 87-89. Iowa Hill, Placer Co., Cal., 76. Irish Hill Mine, Amador Co., Cal , 270. Irkutsk, Siberia, 20, 24. Iron pipe, 49, 158-176. Island Lake Dam and Reservoir, Ne- vada Co., Cal., 95, 104. Italy, 15, 158.

Jack's Hill Claim, Plumas Co., Cal., table li.

Jackson, L. D'A.. cited, 119,

Jackson Creek, Amador Co., Cal., 270.

Jack on Lake, Dam and Reservoir, Nevada Co., Cal., 95, J04.

Jacobs, cited, 16, 18, 20.

Jamestown, Tuolumne Co., Cal., 51.

Japan, 19, table lii.

Japgn, Sea of, 25.

Jaragua, Brazil, 70.

Jasper rocks in California, 57, 58, 61.

Jassin River, Italy, 16.

Jemegan, J. L., cited, tables xlii., 1.

Jesuits in California, 44.

Johnson Claim, Patricksville, Stanis- laus Co., Cal., tables xlv., 1.

Johnson's Ditch, Amador Co., Cal.,

Johnston Claim, Calaveras Co., Cal., table li.

Joints of iron pipes, table xiii., 163-

Jordan Ditch, 270.

Juniper Mine, 270.

Jurassic strata in California. 54, 64, 68.

Kaladgi District, India, 17. Kalami River, Siberia, 23, table lii. Kansas Claim, Nevada Co., Cal.,

table li. Kansk, Siberia, 20, 24, table lii. Kashgar Di.strict, Siberia, 21. Kattywar District, India, 17.

Index.

Kawarau River, New Zealand, 36. Kelly Claim, La Grange, Stanislaus

Co., Cal., 242, 274, table 1. Kern Co., 51. Kern Lake, Cal., 53, 56. Ke:n River, Cal., 64, 66. Kettles, Amalgam, 205. Kiandra District, New South Wales,

King's River. Cal , 64. Kinsha-Kiang River, China, 19. Kirk wood, J. P., cited, table xxii. Kirwin, China, 19. Kizii-togoi, Turkistan, 22. Klamath River, Cal , 47, 66, 79, 238. Knight's Ferry, Cal., 270. Knight Wheel, 19 1, 192. Koh River, India, 18. Kordofan, Egypt, 17. Kudo District, Japan, table Hi. Kuen-Lun Mountains, China, 18, 19. Kumaun River, India, 18. Kutter, W. R., cited, 119, 129, 130. Kuznetsof, cited, 22. Kwei-Chow, China, 19.

Lachlan District, New South Wales,

32, table lii. La Grange, Stanislaus Co., Cal., 68,

75, 124, 125, 132, 138, 144, table

xiii., 168, 177, 223, 226, 229, 241,

263, 270, 274, 276, 277, tables xlii.-

xlvi., 1., li. La Ligua, Chili, 27. Lancha Plana, Calaveras Co., Cal.,

La Porte, Plumas Co., Cal., table li. Larkin, Thos. O., cited, 45. Las Casas, cited, 30. Lassen's Peak, Lassen Co., Cal., 63,

Lava overflow, 33, 34, 41, 65, 66, 67,

Lead joints for pipes, 163. Le Conte, Prof. Jos., cited, 271. Leech River, British Columbia, 38.

Lena, Basin of the, Siberia, 20, 24.

Lewis and Clarke Co. , Montana, 40.

Leydenbui District, Africa, 17.

Life of blocks, 225.

Light Claim, La Grange, Stanislaus Co., Cal., 74, 27, 277, tables 1., li.

Light Claim, Patricksville, Stanislaus Co., Cal., 72, 74, 242, 277, table xliii.

Light for hydraulic claims, 246.

Limestones, Carboniferous, in Califor- nia, 66.

Little Giant, 50, 182.

Little York Company, Placer Co., Cal.,

Livermore Valley, Alameda Co., Cal.,

Lock, A. G., cited, 19, 20, 30, 38, table

Logan, W. E., cited, table lii.

Ix>ngitudinal riffles. 227.

Long Tom, 47, 204.

Los Angeles, CaK, 45, 57, 59, 60.

Loss of gold, 263-267.

Loss of quicksilver, 244, 263-267.

Lou-tsze-Kiang River, China, 19.

Lower California, 42, 44.

Lumber for flumes, 149, 150, 153-157.

Lydia, Asia Minor, 15.

Macy, C, F., 50.

Madison County, Montana, 4a

Madras, India, 17.

Magnetic iron sands, 79, 88.

Mahratta, Province of, India, 17.

Malabar, India, 17.

Malakoff. Nevada Co., Cal., 73, 88, 89,

table XV., 179,246. Malineca, U. S. of Colombia, 29. Maneero, New South Wales, 33. Manzanita Mine, Sweetland, Nevada

Co.. Cal., 180, 211, 226, 234, 256,

258, 260, 264, table 1. Maori bottom. New Zealand, 36. Maradabad District, India, 18. Marco Polo, quoted, 19. Marengo, Queensland, 34.

Index.

Marine fonnations, California, 65, 66. Mariposa County, Cal., 47, 64, 65, 66. Marlow Reservoir, Nevada Co., Cal.,

Marshall discovers gold in California,

Mafsinak, Siberia, table Hi. M ary bot oM gh District, Victoria, Aus- tralia, table lii. Masonry dams, 97. Mattison, £. E., first uses the hydraulic

method, 48. Mawe, John, on Braril, 70, 71. McCarty's Claim, Nevada Co., Cal.,

table 1. McDoran's Claim, Plumas Co., Cal.,

table li. McDowell County, North Carolina, 39. McGillivray Jos., 49, 51, table li. Meadow Lake Dam and Reservoir,

Nevada Co., Cal., 95, 104. Meagher County, Montana, 40. Measurement of snowfall — see Snoith

fall. Measurement of water — see Water, Mechanical appliances. Various, 185-

Mecklenburg County, North Carolina,

Mendell, Lieut.-Col. Geo. H., cited,

77, 113, 114, 118, 211, 239, 240,

268, 276. Mendocino, Cape, 43, 59, 79. Mendoza, Viceroy, 43. Merced River, Cal., 64, 236, 238. Mercury — see Quicksilver. Messerer. Jos., cited, 276, table 1. Metamorphism of rocks in California,

Methods of mining gold placers, 78-86. Mexico, 30. Miask District, Siberia, 21, 72, table

Middle Lake Dam and Reservoir,

Nevada Co., Cal., 95, 104. Miller's Flat, New Zealand, 36.

Milton Mining Company, Nevada Co.,

Cal., 93. 94, 95, loi, 104. 124, 131.

132, 133. 134. 138, 139. 146. 153-156,

table xiii., 180, 211, 234. Mina Real, Cana, U. S. of Colombia,

Miner's ditch, table xiii. Miner's inch, 121-134, 268-274, 277,

278, tables xlii.-xlvi. Minimum pay 3rield of gravel, 76. Mining methods— see Methods, Minusinsk, Siberia, 20, 24, table lii. Miocene Mining Company, Butte Co.,

Cal., 142, 150. 151. Miocene strata in California, 58, 59, 60,

Mission in Lower California, First, 44. Mission in Upper California, First, 44. Mitchell River, Victoria, Australia, 32. Mocupia Valley, Venezuela, 28. Mojave Desert, San Bernardino Co.,

Cal., 60. Mokelumne Hill, Calaveras Co., Cal.,

Mokelumne River, Cal., 77, 115, 118,

238, 239, 240, 268, 269, 270, 276. Molyneux River, New Zealand, 36. Monitor, Globe, 50, 180, 181. Monitor Hydraulic Machine, 183, 184. Montana Territory, 40, 81. Monte Rey, Count de, 43. Monterey, Town of, Monterey Co.,

Cal., 45. Monterey Bay, Cal., 44, 56, 57. Monterey District, Cal., 44, 45. Montgomery County, Virginia, 39. Montreal placers, New South Wales,

Mooney's Flat, Yuba Co., Cal., 232. Moore, Joseph, cited, 170. Moore's Flat pipe, Nevada Co., Cal.,

table XV. Mother-lode of California, 65. Mudgee District, New South Wales,

Munroe, H. S., cited, 20, 70, Uble lii.

Index.

Murchison, Sir Roderick, cited, 70, 71. Murojnaia River, Siberia, 23, table Hi. Murray & Dougherty's Ditch, Calave- ras Co., Cal., 270. Musa Valley, Japan, 19, table Hi. Mysore, India, 18.

HBfjmtt, India, 18.

Nagler Claim, El Dorado Co., Cal.,

table li. Narrow and deep ditches, 137. Naseby, New Zealand, 36. Navigable waters of California affected

by hydraulic mining. 238. Nebraska Claim, Nevada Co., Cal.,

table li. Nelson District, New Zealand, 35. Nepal, India, 18.

Nerchinsk, Siberia, 20, 35, table lii. Nevada County, Cal., 48, 49, 50, 63,

71, 72. 73, 93. 124, 145. 160. 204.

207, 208, 210, '211, 223, 226, 234,

258, 271, tables 1.. li. Nevada, State of, 160, 172. New Almaden, Santa Clara Co. , Cal. ,

New Chum Hill Diggings, New South

Wales, 33. Newchwang, China, 19. New Claim, Patricksville, Stanislaus

Co.. Cal., toble 1. New England, 39. New Hampshire, State of, 39. New Kelly Claim, Stanislaus Co., Cal.,

69, 265, table L New Light Claim, Patricksville, Stanis- laus Co., Cal, table 1. New Mexico, 40. New South Wales, 30, 32, 67, 70, table

New Westminster, British Columbia, 38. New Zealand, 35.

Nijneudinsk, Siberia, 20, 24, table lii. Nile Valley, Egypt, 16. Nine-Mile Diggings, New South Wales,

Nolbt River, Siberia, 22.

North Bloomfield, Nevada Co., Cal.

73, 86. 88, 89, 93. 94, 95# 103, 1<M,

tablcsT., vi., 124, 126, 131, t3a, 134,

13S, X4$, 153. tables ii., xv., 169.

174, X77, Uble xxii.. 179, 185. 221,

226, 227. figs. 67-69, 234, 244 246.

252, a53 3. a64. a74, 76, 378,

table 1. North Carolina, State of, 39. Notch, Triangular, Dischaige of watf

throttgh, I90, t22. Notre DAme Mountains, Canada, 37. Zova Scotia, 37. Nozzles, 49, 158-184, 189, 190. Nubia, 16. Nuggety Gully, Victoria, Australia,

Nuliez, Alvarez, Expedition to Gulf of

California, 42.

Ogilvy's America," 45.

Ogne Valley, Siberia, table lii.

Okhotsk Sea, 25.

Oldest alluvial gold deposits 'known, ' 33. 67.

Olekma River, Siberia, 24.

Olekminsk, Siberia, 20, 24, table lii.

Olizal, Monterey District, 45.

Ollonokon River, Siberia, 24.

Omega and Blue Tent Reservoirs, Ne- vada Co., Cal., 95.

Open channels, Flow of water in, 119,

Opening a claim, 217.

Oreo River, Italy, 16.

Oregon, State of, 45, 66, 79.

Oregon Gulch Ditch, Trinity Co. , Cal.,

Orenburg District, Siberia, table lii.

Orifices, Discharge of water through, I 19-123.

Orinoco River, Venezuela, 29.

Osborne's Flat, Victoria, Australia, 73.

Oshima Province, Japan, table lii.

Otago District, New Zealand, 35.

Index.

Pactolus Mine, Timbuctoo, Yuba Co., Cal., 233. table li.

Pactolus River, 15.

Palmas, Cape, Liberia, Africa, 17.

Palo Escrito Hills, Cal.. 56.

Fampluna Province, U. S. of Colom- bia, 29.

Pan, The gold or miner's, 302.

Paragon Mine, Placer Co., Cal., 208, 227, table li.

Parinacochas Province, Peru, 28.

Park Canal and Mining Company's Ditch, table xiii.

Park Canal and Mining Company's Inch, 124.

Patricksville, Stanislaus Co., Cal., 72, 73. 74 132, 228, 241, 270, Ubles zliii.-xlvi., 1.

Pay gravel, Minimum 3rield, 76.

Payson, Lieut. A, W., cited, 270.

Paz Soldan, cited, 28.

Peace River, British Columbia, 38.

Pearce City, Idaho, 39.

Peel District, new South Wales, 33 table lii.

Pelton wheel, 191-193, 198-202.

Penchenga River, Siberia, 24.

Percolation, 92.

Perkins, U. C, cited, 50, 183, tables

Perm District, Siberia, table lii.

Peru, 27.

Peschanka Mine, Ural Mountains, 21.

Petorca, Chili, 27.

Petroleum in California, 59.

Pettee, W. H., cited, 75, tables 1., li.

Philippine Islands, 18.

Philippsburg, on the Rhine, 16.

Plirygia, 15.

Piede Cuesta Mine, U. S. of Colom- bia, 29.

Piety Hill Mine, Shasta Co., CaL, table li.

Piling for dams, 96.

Pillarcitos Dam and Reservoir, San Mateo Co., Cal., 99, 104.

Pine Grove Reservoir, 95.

Pioneer Mine, Plumas Co., Cal., 318.

Pioneer Tunnel, Sierra Co.. Cal.,

Uble li. Pipe, 49, 158-184, tables xlii.-xlvi. Piquituirin River, Peru, 28. Pittsburg Mine, Sucker Flat, Yuba Co.,

Cal., 232, table It Placer County, Cal., 51, 63, 71, 75, 76,

83, 84, 227, table L Placerville, Placer Co., Cal., 33. Platinum in beach sands, 79. Pliny, cited, 16, 82. Pliocene gravels in California 54, 60,

Pliocene gravels in South Australia,

Pliocene gravels in Victoria, Australia,

Plumas County, Cal., 63, 65, 66, 83,

218, Ubles 1., li. Po River, Italy, 16. Podkamenny Tungusska River, Siberia,

Polar Star Mine, Placer Co., CaL, 71,

75. 179. 239 271. table li. Pond Mine, Placer Co., Cal . table li. Post-pliocene in California, 68. Post-tertiary in California, 64. Powder, Blasting, 210, 212, 233, 234,

Preliminary work in mining, 87-89. Prescott, W. H., cited, 30. Preservation of iron pipes, 167. Pressure on pipes, table xv., 174, tables

xlii.-xlvi. Pressure box, 176, 177. Product of gold : Africa, 17.

Amur basin, Siberia, 95. Bolivia, 27. Brazil, 26.

British Columbia, 38. California, 42, 288. Caratal Mines, Venezuela, 38. Chili, 27.

Index.

Product of gold — €ontinu€d:

Idaho, 39.

Japan, 20.

Montana, 40.

New Granada, 30.

New South Wales, 32.

Peru, 27, 28.

Russia, 21.

Savaglikon Mines, Siberia, 23.

Verkneudinsk District, Siberia, 24.

Victoria, Australia, 30. Prospect drifts, 83, 87, 88.

" shafts. 87, 88, 89.

tunnels, 83. Prospecting, Cost at North Bloomfield,

Puddle, 96, 100. Puddling box, 205. Pumpelly, R., cited, 18, 19, table Hi. Punjab, India, 18. Puno, Department of, Peru, 28. Punta de los Reyes, Cal., 44. Purus River, Peru, 28. Pyrenees Mountains, 16.

Qv er Hill, Placer Co., Cal., 75,

table li. Quartz veins. Gold, in California, 48,

Quebec, Province of, Canada, 37,

table Hi. Queen Charlotte Sound, New Zealand,

Queensland, Australia, 30, 34. Queenstown, New Zealand, 36. Quicksilver, Amount used in charging

sluices, 244. 266. Quicksilver, Loss of, 244, 266, 267. " ores in California, 58.

Treatment of, 249.

Railroad Flat, Calaveras Co. , Cal., 270. Rainfall, 62, 91, 93, 105, tables v., vi.,

Raleigh, Sir Walter, 29. Randall, P. M., cited, 273.

Randolph, E., cited, 44.

Rankine, W. J. M., cited, 97, 98,

table xxii. Ras>£lba, Egypt, 16. Rathget, J., on the yield of the gravel

deposits in Calaveras Co., Cal.,

table li. Ratio of evaporation to rainfall, 92. Rawhide hose, 49. Raymond, R. W., cited, 40, 142, tables

xHi., li. Recent alluvial deposits in CaHfomia,

Records of gold-washing, 15-43.

Red Bluff, Tehama Co., Cal., 53.

Red gravel, 87.

Red Sea, 16.

Reid, cited, 32.

Reid's Creek, Victoria, Australia, 73.

Reservoir-, 90-118.

Retorting amalgam, 249.

Riberio River, Brazil, 25.

Riffles, 224-227, 234. 257, 259, 271,278.

Rifle for discharge pipe, 50, 182.

Rio das Mortes, Brazil, 25.

Rio Grande. U. S. of America, 40.

River channels. Ancient — see also Pli- ocene gravels.

River-mining, 48, 51, 79, 80.

Rivets for hydraulic pipe, 162, 169-171.

Riviere du Loup, Canada, table Hi.

Rock riffles, 224, 259. 271.

Rocker, 203.

Rose's Bar Tunnel, Timbuctoo, Yuba Co., Cal, 232.

Round Lake Dam and Reservoir, Ne- vada Co., Cal., 95, 104.

Rowan County, North Carolina, 39.

Rowdy Flat, Victoria, Australia, 73.

Rudyard — see English (dam and reser- voir).

Rush worth Mines. Victoria, Australia,

Russia, 15, 20, Uble Hi.

Rust of iron pipes, 167.

Rutherford County, North Carolina, 39.

3o6

Index.

Sacramento Ditch, 270.

Sacramento River and Valley, Cal.,

45, 62. 113, 238, 239, 240. Sahara, Desert of, 17. Sailor's Union, Placer Co., Cal., table li. Salinas River, Cal., 56. Salmon River, Idaho, 39. Salt Spring Valley Reservation Ditch,

San Andreas Reservoir and Dam, San

Mateo Co., Cal., 99, 104. San Antonio Mission, Monterey Co.,

Cal., 61. San Antonio, Mount, Brazil, 71. San Antonio, Rio de, U. S. of Colom- bia, 29. San Bartolomo, Rio de, U. S. of Co-

lombia, 29. .San Benito River, Cal., 56. San Bernardino Mountains, San Ber- nardino Co., Cal., 64, 65. San Diego County, Cal., 44, 45, 65,

San Francisco, San Francisco Co., Cal.,

San Francisco Cation, Los Angeles

Co.. Cal., 61. San Francisquito Placers, Los Angeles

Co., Cal., 45. San Gabriel, Los Angeles Co., Cal.,

55, 59. 61. San Gavan, Peru, 27. San Isidro (see also San Diigo\ 45. San Jago, Falls of, U. S. of Colombia,

San Joao, Brazil, 71. San Joaquin Valley and River, Cal.,

62, 238, 269. San Jos<f, Brazil, 71. San Juan, Nevada Co., Cal., 138, 140,

tables xiii., xv., 234. San Juan del Oro, Peru, 28. San Luis Rey, San Diego Co., Cal., 55. San Mateo County, Cal., 99. San Pablo Bay, Cal., 238. Sand-box, 177.

Sandhurst District, Victoria, Australia,

Sandia, Province of, Peru, 28.

Sands, 72.

Sangre de Cristo Mountains, New Mexico, 41.

Santa Afia Mountains, Los Angeles Co , Cal., 55, 60, 61.

Santa Barbara County, Cal., 59, 61, 68, 168.

Santo Clara County, Cal., 174.

Santa Clara River, Cal., 60. j Santa Cruz de Cana, U. S. of Colom- I bia, 29

Santa Cruz Mountains, Cal., 56, 59, 60. I Santa Cruz River. Venezuela, 28. ' Santa F, New Mexico, 40. I Santa Lucia Range, CaL, 56, 59, 61. j Santa Monica Range, Cal., 57. Santiago, Rio de, U. S. of Colombia,

Savaglikon, Valley of, Siberia, 23, I table Hi.

Saw Mill Flat Dam, Nevada Co., Cal.,

Schmidtmeyer, cited, 26, 29.

Scotchman's Tunnel Claim, New South Wales, 33.

Scott's Valley placers. Trinity Co., Cal., 47.

Sebastopol, Nevada Co., Cal., table 1. ! Secchi, S.J., Father, cited, 158.

Secret Diggings, Plumas Co., Cal., table li.

Sedimentary volcanic layers, 66.

Selwin, M. A., cited, 70.

Semipalitinsk, Siberia, table Hi.

Senegal River, Senegambia, Africa, 17.

Serio River, Italy, 16.

Serpentine rocks is California, 57, 58. . j Serra, Father Junipero, cited, 44. I Sevilla, Rio de, U. S. of Colombia, 29.

Shaargans Valley, Siberia, toble Hi.

Shaft timbering, 216.

Shafts, Prospect, 87, 88, 89.

ShafU for tunnels, 215.

Index.

Shallow placersy 78. Shantung, Province of, China, 19. Shasta County, Cal., 55, 62, 66, table li. Shasta, Mount, California, 63, 66. Sbelvocke. Captain Royal Navy, Voy- age around the World by Way of the

South Sea," 45. Shensi, Province of, China, 19. Shiribeshi, Province of, Japan, table

Hi. Shot Gun Lake Reservoir anil Dam,

Nevada Co., Cal., 95, 104- Shotover River, New Zealand, 36. Shrinkage of embankments, loo. Siberia, 15, table lii. Sicard Claim, Stanislaus Co., Cal., 72,

tables xlvi., 1. Sierra County. Cal., 63, 83, 84, table li. Sierra Nevada. Belt of the, 53, 54. 63,

Silliman, Professor, cited, 40. Silurian deposits at Beechworth, 32. Silurian deposits of Canada, 37. Silver mines in California, 61. Sipage through dams, 94, 115. Siphons, 49. 158. Sites for storage reservoirs, 90. Skidmore, W. S., cited, 76. Slate formations in California, 58, 59,

64,67. Slope. Average of the Sierra Nevada,

Slopes of banks, 102, 138. Sluice, affects the duty of the inch, 268. Sluice, Definition of, 218. Sluice diggings, 78. Sluices, Action of vrater in, 272. Sluices, Charging the, 244. 266. Sluices, Construction and location of,

215. 235, 259. Sluices, Distribution of gold in, 252-

Sluices, Grades of, 218, 227-231, 259,

266, 274, 277-279, tables xUi.-xlvi. Sluices, Ground, 247. Sluicing, Ground, 79, 81.

Smartsville, Yuba Co., Cal., 114. 124,

140, table XV., 206, 226, 232, 246,

tables 1., li. Smith, H., Jr., cited, 95, 112, 125, 126,

174, 188, 273, tables 1., li. Smythe, R. Brough, cited, 17, 70, 253, Snake River, Idaho, 39, 40. Snow Mountain Ditch, Nevada Co.,

Cal.. table xiii. Snowfall, 91, 93, 105, tables v., vi. Soetbeer, Dr., cited, 17, 26, 27, 28,

Sofala, 17.

Solfataric action in California, 54, 61. Sources of water supply, 90. South Australia, 30-34. South Carolina, State of, 39. South Island, New Zealand, 35. South Yuba Canal Company, Nevada

Co., Cal.. 95, loi, 104, 124, 138, 140,

tables xiii., li. Southern Cross Mine, Placer Co., Cal.,

179. 239, 271. Southern District, New South Wales,

32, table lii. Spain, Gold-washing in, 16, 82. Spanish Claim, El Dorado Co., Cal.,

table li. Spearfish River, Dakota Ten, 146. Spike's Gully. South Australia, 34. Spring Valley and Cherokee Mining

Company, Butte Co., Cal., 49, 103,

138, 141, table xiii.. 162, table xv.,

174. 175. Spring Valley Water Company, San

Francisco, 104, 160, table xv., 162,

170, 171. St. Helena, Mount, CaL, 61. St. Lucas, Cape, Lower California, 44, Stanislaus County. Cal., 68, 72, 74,

124, 125, 132, 138, table xiii., 168.

177, 226, 229, 241, 263, 265, 270,

274, 276, tables xliii., xliv., 1., li. Stapleton River, South Australia, 35. State Engineer of California, cited, 77,

238, 239, 240, 268, 271, 276.

3o8

Index.

Stearns, E. P., on measurement of water, 119, 120.

Sterling Reservoir, Nevada Co., Cal.. 95, 104.

Stickeen River, British Columbia, 38.

Stockton Ridge, 270.

Storage of tailings, 112, 115.

Storage reservoirs, go.

Stove-pipe. 49.

Strabo, cited, 15, 16.

Strain, Tensile — sec Tensile.

Strains on pipes— sec Pressure.

Strassburg on the Rhine, 16.

Strelok Bay, Siberia, 25.

Striedinger, J. H., cited, 213.

Stutchburg on the distribution of gold- en gravel, 70.

Suakin, Egypt, 16.

Sucker Flat, Yuba Co., Cal., 207, 232, table li.

Suisun Bay, Cal., 61, 238.

Sulphur in California, 61.

Sunny South Mine, Placer Co., Cal.,

Supply of water. Sources of, 90. Supply pipe. 158, 178. Surface-mining, 78, 79. Surtur River, India, 17. Surveying a ditch line, 136, 152,

Suspension of material in water, 240,

Sutter Creek, Amador Co., Cal., 270. Sutter's Fort, Cal., 46. Sweetland, Nevada Co., Cal., 180, 211,

213, 226, 234, 256, 258, 260, 264,

table 1. Sweetland Creek Tunnel, Nevada Co.,

Cal , 234. Szc-Chuen, Province of, China, 19.

Table i. Production of gold in Russia,

Table 2. Reservoirs in California, 95. Table 3. Angles of repose and friction

of embankment materials, 102.

Table 4. Principal dams in California,

Table 5. Rainfall at North Bloomfield and Bowman Dam, follows p. 118.

Table 6. Rainfall and snowfall at Bow- man Reservoir, follows p. 118.

Table 7. Discharge of water through triangular notches, 122.

Table 8. Coefficients of discharge of water through rectangular orifices,

Tables 9, 10, 11. Lumber for flumes, Dimensions of, 149, 150.

Table 12. Details of cost of Milton Ditch and Flume, 154, 155.

Table 13. Dimensions, capacity in inches, grade, and costs of ditches in California, follows p. 156.

Table 14. Thickness and weight of iron for pipes, 159.

Table 15. Thickness of iron, maximum tensile strain on wrought-iron pipes, follows p. 160.

Table 16. Area and weight of wrought- iron pipes, 161.

Table 17. Sizes of rivets, 162.

Table 18. Details of riveting a 22-inch wrought-iron pipe, 162.

Table 19. Costs of constructing iron pipes, 169.

Table 20. Details of construction of the Spring Valley Water Company's wrought-iron pipe, 171.

Table 21. Showing thickness of iron, pressure, and maximum tensile strain on the Spring Valley and Cherokee Mining Company's pipe, 174.

Table 22. Flow of water through cir- cular pipes. Coefficients of, follows p. 174.

Table 23. Experiments with Hurdy- Gurdy wheels at the North Bloom- field Mine, 189.

Table 24. Bank-blasting at the Manza- nita Mine, Sweetland, Nevada Co., Cal., 212.

Index.

Table 25. Lengths and grades of tun- nels in Smartsville District, Yuba Co., Cal.. 232.

Table 26. Lengths, grades, and costs of tunnels in Nevada Co., Cal., 234.

Table 27. Cost of the French Corral tunnel and sluices 233.

Table 28. Cost of the Manzanita Mine tunnel and sluices, 234.

Table 29. Halt's estimate of hydraulic debris in California rivers, 239.

Table 30. Mendell's estimate of hy- draulic debris in California rivers,

Table 31. French Corral Mine Under- currents, 257.

Table 31 A. Yield of gold from the un- dercurrents, etc., at French Corral, Nevada Co., Cal., 258.

Table 32. Yield from the undercur- rents, etc., at Manzanita Mine, Ne- vada Co., Cal., 258.

Table 33. Distribution of gold in the sluices of the Manzanita Mine, 260.

Table 34. Distribution of gold in the sluices of the French Corral Mine,

Table 35. Distribution of gold in the sluices of the North Bloomfield Mine, 262.

Table 36. Amount of water used, yield of bullion, and loss of quicksilver at the North Bloomfield Mine, 264.

Table 37. Details of a run at the New Kelly and Delaney Claims, showing amount of water used, bullion yield, and loss of quicksilver, 266.

Table 38. Estimates of the amount of water used and the duty of the inch,

Table 39. Estimates of the amount of water used and the duty of the inch by Lieutenant Payson, 270.

Table 40. Estimates of the amount of water used and the duty of the inch by the State Engineer, 271.

Table 41. The amounts of water used and the duty of the miner's inch at North Bloomfield and La Grangtf mines, 274.

Table 42. Amount of water used, quantity of gravel washed, grade, height of banks, details of cost, and bullion yield at the French Hill Claim, Stanislaus Co., Cal., follows p. 279.

Table 43. Amount of water used,

gravel washed, grade, height of

banks, yield of bullion, and costs of

working the Light Claim, Patricks-

ville, Stanislaus Co. , Cal. , follows p.

I Table 44. Details of working the Ches-

I nau Claim, Patricksville, Stanislaus

I Co , Cal., follows p. 279.

Table 45. Details of working the John- son Claim, Stanislaus Co., Cal., fol- lows p. 279.

Table 46. Details of working the Si- card Claim. Patricksville, Stanislaus Co., Cal., follows p. 279.

Table 47. Rume of the work done by the La Grange Company from June I, 1874. to September 30, 1876, 277.

Table 48. Amount of water used, gravel washed, height of banks, yield of bullion, and cost of work- ing No. 8 Claim, North Bloomfield, Nevada Co., Cal., 278.

Table 49. Classification of mines and mining expenses in California, 279.

Table 50. Amount of gravel moved and yield of important hydraulic claims in California, follows p. 279.

Table 51. Amount of gravel moved and yield of various placer claims in California, follows p. 279.

Table 52. Amount of gravel washed and corresponding yield of foreign gold-fields, follows p. 279.

Table Mountain, Tuolumne Co., Cal., 51,66.

3Io

Index.

Table Mountain Creek, Cal., 239,

Table-Top Mountain, New South

Wales, 33. Tagus River, Portugal, 16. Tahoe, Lake, Cal., 64. Tail sluices — see Sluices. Tailings, 112-115, 236-240. Tailings deposited in streams, 114,

236, 238-240. Tailings, Storage of, 112, 115. Talca, Chili, 27. Tallawang District, New South Wales,

Tambaroora District, New South

Wales, 32. Tamping powder drifts, 213. Tapu District, New Zealand, 36. Tarring iron pipes, table xv., 167,

Taylor Wheel, The, 191, 193. Tejon, Fort, Kern Co., Cal., 53, 55,

59, 61, 62, 63. Temescal Range, 55, 60. Temora placers, New South Wales,

Temperance Hill, Yuba Co., Cal.,

table li. Temple, £. , on distribution of gold, 70. Tensile strain on pipes, table xv., 172,

Tcntek River. Western Turkistan, 22.

Tertiary alluvial deposits in New South Wales, 34.

Tertiary strata of California, 54, 57, 58, 59, 60, 64, 66.

Tesorcro, Venezuela, 29.

1 exas Creek ditch and flume, 131.

Texas Creek pipe, Nevada Co., Cal., 160, table XV.

Tiya River, Siberia, 22,

Thames Gold Fields, The. New Zea- land, 36.

Thibet, 18.

Thickness of iron for pipes, 159, table XV., 161, 162, 168, 169, 171, 172.

Thompson, Prof.. Experiments on the discharge of water through triangular notches, 120.

Tiltil, Chili, 27.

Timber-crib dams, q6, 106, 1 10.

Timbering shafts, 216.

Timbuctoo, Yuba Co., Cal., 49, 232.

Tinkers Diggings, New Zealand, 36.

Tin oxide, 88.

Tin ore in California, 60.

Tipuani River, Bolivia, 27.

Tom, The, 47, 204.

Tools for pipe-making, 169.

Topography of California, 53, 69.

Torrens River, South Australia, 34. i Toshibitsu, Province of, Japan, table

Transactions of the American Institute of Mining Engineers, 20, 70, table Trans- Baikal ia. Siberia, 20, 24, table

I Transporting capacity of a current,

I Transporting power of a current, 271. I Transvaal, South Africa, 17. i Trautwine. John C, cited, 99. 100, I loi.

I Travancorc, State of, India, 18. Treaty of Guadalupe- Hidalgo, 47. Tres Pinos, San Benito Co., Cal., 60. Triangular notch. Discharge through,

120, 122. Triassic strata in California, 54, 58,

Trinity County placers. Discovery of,

Trinity River, Cal., 49, 66, 238. Tuapeka. New Zealand, 36. Tujimo River, Siberia, 24. Tulare County, Cal., 65. Tulare Lake, Cal., 58. Tunnels and sluices, 215-235. Tunnels, Deep, first in California, 51. Tunnels for drift-mines, 83. Tunnels, Prospect, 83.

Ix Dex.

Tuolumne County, Cal., 51, 64, 66,

Tuolumne River, Cal., 64, 68, 72, 77,

238, 241, 270. Tuolumne Water Company, 103, 104,

table xiii. Turkistan, 20, 22. Turn-in sluice, 227, 228, 229. Turn-out sluice, 227, 229-231. Turon District. New South Wales, 32. Twist's Fall, Victoria, Australia, 73.

Uderey, Valley of the, Siberia, 23,

table lii. Umpqua River, Oregon, 79. Undercurrents, 23 r, 232, 247, 257,

259, 261. Undercurrents, Distribution of gold in,

Undulations, Rich pay in, 72. Union Ditrh, Yuba Co., Cal., 138,

140, table xiii. Union Ditch, Calaveras Co., Cal.,

Union Gravel Mine, Yuba Co., Cal.,

table li. United States of America, 38. Untuguna River, Siberia, 24. Ural Gold Fields, 20, 21, 88, table lii. Uralla District, New South Wales, 32,

table lii.

Vaca, Cabeza de. Expedition to Gulf of California, 42.

(Valparaiso, Chili, 27.

Valves for iron pipes, 166, 167.

Vancouver Island, British Columbia,

Veins, Gold quartz, in California, 48, 61, 65.

.Ven;as, Father, Discovery of Cali- fornia, 42, 61.

Venezuela, 28.

Ventura County, Cal., 59, 61.

Verkneudinsk, Siberia, 20, 24.

Vermont, State of, 39.

Victoria, Australia, 30, 70, 71, 205,

253, table lii. Victoria, British Columbia, 38. Vigno Hill, Stanislaus Co., Cal., 274. Virginia City and Gold Hill Watefr

Company, Nevada, 160, table xv,,

163, 172, 173. Virginia, State of, 39. Visalia, Tulare Co., Cal., 53. Viscayno, Sebastian, 43. Vitim River, Siberia, 24. Volcanic activity in California, 54, 6i. Volcanic cones in California, 66. Volcanic layers. Sedimentary, 65, 66. Volcano Mine, 270.

Wairau Valley, New Zealand, 37. Wakamarina District, New Zealand, 37. Waldron Reservoir, Nevada Co., Cal.,

Wallace, H. W., on yield of gravel at Bald Mt., Sierra Co., Cal., table li. Walls, Puddle, 96, 100. Walsh, Travels in Brazil, 25, 71. Waranga Gold Fields, Victoria, Aus- tralia, 32. Washing, First, 27. Washing, Method of, 244-351. Washington Territory, 39. I Washoe Valley, Nevada, 172. Waste-gates— ditches, 133. 134, 136,

I Waste-gates — flumes, 128, 145, 154. I Water, Absorption of, 92, 132, 135,

j Coefficients of discharge I through circular pipes, table

" Coefficients of discharge

through ditches, 1 31-133. " Coefficients of discharge through rectangular orifices, Discharge over weirs, 119, 120. " Discharge through nozzles,

Index.

Water, Discharge through orifices,

' Discharge through pipes, table

XV.. 174. Discharge through triangular

notches, 120, 122. Duty of the miner's inch, 268,

274, 277, 278, tables xlii.-

Erosion of material in, 236,

Evaporation of, 92, 135, 143. Flow in ditches. 130-134. Flow in narrow and deep

ditches, 137. Flow in open channels, 127. Loss of, table vi., 132, 133,

134. 143-

Loss in distribution, 133.

Pressure on pipes, table xv., 174, tables xlii.-xlvi.

Measurement of, 1 19-134.

Supply, Sources of, 91.

" Suspension of material in,

" Transporting capacity of, 271.

Transporting power of, 271. Wheel— see Hurdy-Gurdy, Wear of stones in running water, 236,

Weaver Lake Reservoir and Dam,

Nevada Co., Cal., 93, 95, 104. Wei River, China, 19. Weight of wrought-iron plate. 159. Weight of wrought iron in pipes, 161. Weirs, 119, 120. Weisbach. Julius, cited, 119. Werchneudinsk, Siberia, table lii. Werong, Mount, New South Wales,

Westland District, New Zealand, 35,

Wheel — see Hurdy-Gurdy, White River, Cal., 66. Whitesides Claim. El Dorado Co..

Cal., table li.

Whitney, J D., cited, 53, 70. 276.

Whitney, Mount, Cal., 64.

Wilkes' Exploring Expedition, 45.

Wilkinson, C. S., on auriferous coal measures, 67.

Wing dams, 48.

Wood, Fossil, in California. 67.

Wooden dams (see also Timber cribs),

Woodward Claim. Nevada Co., Cal.,

Woolsey Flat, Nevada Co., Cal., 234.

Woolshed, Victoria, Australia, 73.

Wright, P., Distribution of gold in tail sluices, 253.

Wrought-iron pipes— see Fipes and noztUs.

Wynaad Gold Fields, India, 17.

Wyoming and Dakota Water Com- pany, Dakota, 146, 147.

Yackandanah, Victoria, Australia, 73. Yenisei River, Siberia, 22. Yeniseisk, Northern Siberia, 20, 22,

toble lii. Yeniseisk, Southern Siberia, 20, 23,

table lii. Yenashimo Valley, Siberia. 23, table

Yes so, Japan, 20. Yield — see Product of gold. Yield from the auriferous deposits of

California, 42. 275, 277, 278, tables

xlii.-xlvi.. l..li., 288. Yield of auriferous gravel — see Re- cords of gold-wcuMng,

of the different gravel straU, 72,

74, 75. ' of the different gravel strata at North Bloomfield, 73, 74. of the different gravel straU at

Patricksville, 74. of drifting and hydraulicking

at North Bloomfield, 84, 278. of the Russian, Australian, and

Japan gold fields, 20, table lii.

Index.

Yield of gravel at La Grange, 74, 277, tables xlii.-xlvi.

" of minimum pay of gravel, 76.

of top dirt at La Grange, 74.

of top dirt at the Polar Star Mine. 75.

" of undercurrents — see Distribu- tion of gold itt undercurrents.

of sluices — see Distribution of gold in sluices.

Yuba Co., Cal., 95, 124, 138, 140, table xiii., 206, 207, 226, 232, 273, tables 1., li.

Yuba River, Cal., 77, 93, 95, 103, 114, 115, 235. 239, 245, 268.

Zapaterito River, U. S. of Colombia, 39. Z6hya River, Siberia, 25. Zipangu, Japan, 19. Zlataust, Russia, 22.

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