840 



NA TURE 



[December 23, 1922 



and a well-printed, if rather small-scale coloured map. 

 The notes on topography are very brief, covering 

 ely two pages, while climate is dismissed in a few 

 lines. More considi ration of these fundamental aspects 

 i.f tin economic life of the country would enhance the 

 value of the book! 



( )f all the new or newly constituted states of Europe 

 probably none has greater possibilities than Czecho- 

 slovakia. Its central situation, varied resources, and 

 rich mineral endowment combine to promise a bright 

 future. Racially also it has fewer thorny problems to 

 solve than most of the new states. Czechs and Slovaks 

 together comprise 68 per cent, of the population, and 

 the only considerable non-Slavonic element is 22 per 

 cent, of Germans, mainly in Bohemia. At the same time 

 the Ljreat difference in cultural status between the 

 Czechs and Slovaks, which is emphasised by the com- 

 paratn e lai k of communication between their respective 

 countries, is a hindrance to the consolidation of the 

 State. The vp\ ernment is fully aware of this difficulty^ 

 and is facing it by the improvement of communications. 

 The section of the Elbe from Aussig to Neratovice 

 has been canalised and operations are in progress as 

 far as Pardubice. From there a canal, no miles long, 

 will be built to Prerau on the Beczwa in Moravia. A 

 Danube-Oder canal is also under consideration. 



R. N. R. B. 



Technical Electricity. By II. T. Davidge and R. W. 

 Hutchinson. Fourth edition. Pp. xii + 514. (Lon- 

 don : University Tutorial Press, Ltd., 1922.) 105-. (>d. 

 The object of the authors of this volume is to give a 

 clear exposition of physical principles and to show 

 how they are applied in engineering practice. This 

 is done satisfactorily, and we think that the volume 

 will prove useful to engineering students in the first 

 and second year of their course at a technical college. 

 Engineering practice and phraseology change rapidly, 

 so it is difficult to keep an engineering treatise absol- 

 utely up-to-date. For example, the phrase " mean 

 spherical candle-power " is rapidly becoming obsolete. 

 Engineers now use the much more sensible phrase 

 "the average candle-power"; similarly a "half- 

 watt " lamp is now termed a " gas-filled " lamp. It 

 is not strictly correct to say that the international 

 candle-power " is now defined as an illuminating 

 power equal to one-tenth of that of the Harcourt- 

 Pentane lamp." When engineers refer to the inter- 

 national candle they mean the unit of luminous power 

 maintained by the National Physical Laboratories of 

 France. Great Britain, and the United States of 

 America. The Hefner-kerze is used by Germany and 

 Austria, and its numerical value is nine-tenths of that 

 of the international candle. Hence the candle-powers 

 given by lamp manufacturers in Germany are expressed 

 by larger numbers than if they were expressed in 

 international units. This is to their commercial 

 advantage. We were surprised that the international 

 standards for the resistance and temperature-co- 

 efficients of pure annealed copper are not given, as 

 they are of fundamental importance in electrical 

 engineering. We hope that the wire gauges, the table 

 for the resistance of copper wires (temperature not 

 stated), and the tables of fusing currents will be 

 omitted from the next edition. 



NO. 2773, VOL. I 10] 



Notes on Qualitative Analysis : Concise and Explanatory. 

 By Dr. H. J. H. Fenton. Supplement. Pp. V+ 155- 

 202. (Cambridge : At the University Press, 1922.) 

 35. 6d. net. 



This pamphlet forms a supplement to Dr. Fenton's 

 well-known " Notes on Qualitative Analysis." The 

 more important and characteristic reactions are given 

 of the rarer elements of more general interest which 

 can be identified by chemical tests. References to 

 " spectra," without any details, are made. No de- 

 scription is given of possible methods of separation. In 

 arranging the elements according to alphabetical order, 

 their chemical relationships are quite obscured, and 

 the information conveys the impression of isolated 

 snippets. The selection of the inorganic and organic 

 compounds is, as the author emphasises, quite arbitrary : 

 one notices more particularly the substances studied 

 by Dr. Fenton himself. Although the book may prove 

 useful to teachers who have not access to the larger 

 treatises, its lack of system and reasonable completeness 

 will somewhat diminish its value as compared with 

 existing manuals of qualitative analysis such as that 

 of Treadwell. 



The Fishing Industry. By Dr. W. E. Gibbs. (Pit- 

 man's Common Commodities and Industries.) Pp. 

 viii+135. (London : Sir I. Pitman and Sons, Ltd., 

 1922.) 35. net. 

 A very concise and comprehensive account of the sea- 

 fishing industry in general is contained in Dr. Gibbs's 

 little volume. There are chapters on the natural 

 history of the edible fishes, molluscs, and Crustacea, and 

 on the methods of fishing, but the distinctive parts of 

 the book are those that deal with the mode of fish- 

 curing and conservation, and with the utilisation of 

 by-products. Written with an evident personal know- 

 ledge of the processes described, these chapters make 

 a really important contribution to the literature of the 

 sea fisheries. J. J. 



Manuel d'oceanographie physique. Par Prof. J. Rouch. 

 Pp. 229. (Paris : Masson et Cie, 1922.) 15 francs. 

 Capt. Rough's book is a well-balanced account of 

 oceanography, treated almost entirely from the 

 physical point of view. The first part deals with 

 methods, soundings, the physics and chemistry of sea- 

 water, the study of currents, tides, and tides and the 

 observation of ice-formation. The second part deals 

 in the usual way with the general results of oceano- 

 graphical investigation. The book is a small one, 

 I nit it is very concise in its treatment, and it is well 

 illustrated. 



Practical Tanning. By Dr. Allen Rogers. Partly 

 based on the Third Edition of " Practical Tanning," 

 by Louis A. Flemming. Pp. xxv + 699. (London : 

 Crosby Lock wood and Son, 1922.) 45s. net. 

 Dr. Rogers is well known for his writings on chemical 

 technology, and as an account of recent American 

 practice his book will prove interesting to English 

 technologists. It deals briefly with all branches of 

 the subject, and is illustrated. The section on analytical 

 methods is brief, but most of the important determina- 

 tions are covered. A short account of synthetic 

 tanning materials is given. 



