The Electro-Metallurgy of Steel

1922 · Historical

For the calculation of approximate predictions Van der Stok's scheme of calculation is explained and used in the book

This 1922 document, The Electro-Metallurgy of Steel, is preserved in the Mountain Man Mining Library for research and reference. Original source: archive.org.

Na Ture

author might justly complain that a similar diagram has been allowed to pass for several years without comment in the Admiralty Tide Tables !

For the calculation of approximate predictions Van der Stok's scheme of calculation is explained and used in the book, and the calculations are facilitated by appropriate tables. Some little confusion is caused, however, by using the same symbol (k) for the phaselag (in degrees) and time-lag (in hours) when the tidal constituent is referred to a fictitious satellite; it is customary to use k for the phase-lag. It is doubtful whether it was wise to depart from the usual rule of stating the astronomical argument; it is customary to make the speeds positive and the arguments therefore increase with time. Except to those using the harmonic method for the first time there is a liability of confusion between theory and practice, a positive speed and a decreasing argument being difficult to reconcile. If, however, the instructions are carefully followed the required predictions can be readily obtained, whether there is much or little diurnal tide.

It ought to be added that a criterion given for the relation between semi-diurnal and diurnal tides so that one maximum per day only can occur, has a very limited application.

The manual gives authoritative explanations of the non-harmonic methods of collecting and using tidal information. In spite of the blemishes mentioned above, the book should serve a useful purpose in making seamen acquainted with the reasons why such methods are often futile. At the same time, it provides an alternative and more exact method, and in doing this Commander Warburg has initiated a movement which, we hope, will lead to much-needed reforms in the everyday applications of tidal science.

A. T. Doodson.

Electrothermic Processes in Steel Manufacture.

The Electro-Metallurgy of Steel. By C. C. Gow. (A Treatise of Electro-Chemistry. Edited by Bertram Blount.) Pp. xvi + 351. (London: Constable and Co., Ltd., 1921.) 27s. 6 d.

HAT are usually called electro-metallurgical processes of steel manufacture now consti tute an applied science of considerable industrial im portance. Strictly speaking, however, the processes are not electro-metallurgical since electrolysis is not an essential feature. Electrical energy is transformed into heat energy which is applied to the making and refining of steel of many types. The possibility of applying electrical energy in this way was first NO. 2746, VOL. IO9]

demonstrated by the late Sir William Siemens almost twenty years before its commercial possibilities were recognised by later investigators.. Prior to the out break of the late war the electric furnace had only a very limited application in steel metallurgy. Since then it has had a rapid and vast development, due partly to the-shortage of high-grade raw materials, partly to the enormous demand for alloy steels, and partly to the need for utilising in some way the vast accumulation of heavy steel turnings. These conditions presented an exceptional opportunity for the electric furnace, and it was only then that its economic advantages in certain branches of steel-making were actually demonstrated. According to Mr. D. F. Campbell, who has written a preface to Mr. Gow's book, the electric furnace is now absorbing millions of electrical horse-power for various purposes and has produced more than a million tons of steels of various types.

Mr. Gow is well fitted to write a book on electrothermic processes of steel manufacture, both on account of his scientific training and his wide experience of steel works practice. These qualifications have stood him in good stead in producing a book which should attract the attention both of students of metallurgy and practical steel-makers. Following an introductory chapter on the historical development of electric steel furnaces, the early chapters deal with the general principles and application of alternating currents. In writing these the author expresses his great indebted ness to Mr. R. P. Abel. Then come chapters on electro thermal methods of melting and refining cold charges and refining liquid steel, and these in their turn are followed by a chapter on ingot casting. Later chapters deal with characteristic principles and features of electric furnace design and modern types of furnaces, suitable refractory materials, and the properties and manufacture of carbon electrodes. Finally, there is an appendix detailing rapid methods of analysis of bath samples.

The melting of steel on a large scale in a strictly reducing atmosphere is possible only in the electric furnace. New phenomena are observed and striking results have been obtained. It is therefore correct to say that the electric furnace gives the steel-maker and refiner a new atmosphere in which to conduct his operations. Owing primarily to the much higher tem peratures which can be reached, steels of inferior grade can be melted and their deleterious constituents to a great extent removed, because it is possible to intro duce refining slags which can be fused and operated only at temperatures reached in the electric furnace. This type of furnace has now rendered available new alloys of special value, such as low carbon ferro-chromium, and high-grade ferro-silicon, which in their turn have

Na Ture

been economically transformed into products such as stainless steel, stainless iron, and transformer iron. The use of the last named has increased the efficiency of electric transformers to an extent which represents an annual saving of hundreds of thousands of tons of coal per annum.

At one time the induction furnace received con siderably greater prominence than the arc furnace. As the author states, many furnace designers, believing that the principle of induction heating was superior, concentrated their efforts on the production of a furnace which could operate on any standard electric supply and at the same time meet all the requirements of thesteel-maker. The position to-day, however, is that almost the entire output of electric steel is made from arc furnaces. The book is clearly printed and well illustrated and will certainly repay study by all those interested in the subject.

Physiology of the Growing Plant.

Encyclopedic scientifique : Bibliotheque de Physiologic et de Pathologie vegetates: Nutrition de la plante. Par M. Molliard. I. Echanges d'eau et des sub stances minerales. Pp. xiv + 395. II. Formation des substances terraires. Pp. vi + 438. (Paris: Gaston Doin, 1921.) 14 francs each vol.

SERIES dealing with the physiology of the grow ing plant in health and disease is being written by Prof. Molliard, Dean of the Faculty of Science of the University of Paris, and the two volumes under notice are the first to be issued. The scope of the series is wider than would usually be undertaken by a single writer, but the author considers that the advantages of uniform treatment will outweigh the disadvantages arising from the attempt to cover so extensive a field of science.

The volumes before us deal with the nutrition of the plant, the phenomena of absorption of nutrients from the soil, the building up of complex substances in the plant and their translocation from leaves to storage organs. The author has succeeded in bringing together a great amount of material that cannot usually be found in the same book, and this will prove a convenience to students. As an example, under the heading " Glucosides " there is not only the usual chemical account of these substances, but illustrations of cross-sections showing the distribution of typical glucosides in growing plants. In this and in other directions, the volumes give to the chemist much information that he does not possess although it may be well known to the botanist, and they give to the botanist a survey of chemical relationships which he might not find so easily elsewhere.

No. 2746, Vol. Io9]

It could scarcely be expected that a book covering so much ground could include anything like all the recent work. The section on soils, for example, contains no reference to many of the investigations made during the last few years. The only grouping of fractions in mechanical analysis of which mention is made is that of Wollny, drawn up forty years ago, no reference being made to the important later develop ments made in the United States, Great Britain, Sweden, or elsewhere. Similarly also, it is assumed that soil possesses the sand-grain structure formerly attributed to it, although this view is now displaced by the later colloidal hypothesis. Fuller justice is done, however, to recent French work, and it is in the summaries of some of these interesting and suggestive investigations that English readers will find the chief interest of the book.

We should like to suggest that in future volumes there should be more references showing the sources from which' the tables are taken. A considerable number of figures are given, but it is not easy to know the exact conditions under which they were obtained, and, as every one who has studied plant nutrition is aware, the phenomena are profoundly affected by alterations in the conditions under which the plant is growing. In particular the section dealing with the mineral constituents of plants would have been greatly improved by fuller references.

Life among the Sema Nagas.

The Sema Nagas. By J. H. Hutton. Published by the direction of the Assam Government. Pp. xviii + 463. (London: Macmillan and Co., Ltd., 1921.) 40s. net.

R. HUTTON has quickly added to his mono graph on the Angami Nagas a second de scribing the allied tribe, the Sema. The latter occupy the watershed dividing Assam from Burma, the plateau and the valleys of three rivers, the most important, the Dayang, eventually flowing into the Brahmaputra and so into the Ganges, the other two mingling their waters With the Lania, and reaching the sea by way of the Ti-IIo, the Chindwin, and the Irawadi. The Sema Nagas are a mixed race, the result of emigration from at least three directions : from the north-west, whence came the Singpos, Kacharis, and Garos ; from the south the Angamis; while a migration from south northwards on the part of the Thado Kukis and Lusheis has scarcely ceased even now.

Mr. Hutton's work is the result of eight years' acquaintance with the Sema Nagas, during which he learned to speak their language, which had not hitherto been reduced to writing, and gained the confidence of a