5i8 



NATURE 



[August 24, 1916 



products in furnishing certain of the raw 

 materials needed in the manufacture of high 

 explosives, the astonishing development of the 

 coal-tar industry in Germany affords one more 

 illustration of the means by which that country 

 has so sedulously prepared herself for the titanic 

 struggle upon which she has embarked. 



It remains to be seen what the influence of the 

 war will be on the future of tar production and 

 distilling in this country. It is practically cer- 

 tain that Germany will no longer be the market 

 for our intermediate tar-products that she has 

 hitherto been. Dr. Lunge tells us, what we begin 

 to realise, that Germany " is now in a position to 

 furnish almost the whole of the requirements of 

 coal-tar products for its colour industry, the 

 largest in the world." What is in store for the 

 colour industry with us is very difficult to fore- 

 cast. Time and a more intelligent fiscal policy 

 may tell. As we all know, attempts are bejng 

 made to recover the great leeway we have lost 

 by our lack of foresight and our want of an intel- 

 ligent appreciation of the relation of science and 

 research to industry. It is to be hoped, in the 

 interest of our textile manufactures, that at least 

 a certain measure of success may be reached. But 

 it is questionable whether, on the lines of the 

 present effort, the success will be very far- 

 reaching. It is certain that the methods which 

 are being employed are very different in character 

 from those which have placed the industry in its 

 present high position in Germany. It is no less 

 certain that no other mode of direction than this 

 last will be successful in the long run. 



As compared with the preceding edition, which 

 appeared in 1909, the most important factor of 

 increase in the present work is in the section 

 relating to ammonia, concerning which there has 

 been a great development within recent years. 

 Ammonia and ammoniacal compounds are, of 

 course, used to a large and increasing extent in 

 a great variety of industries, e.g. manufacture 

 of alkali ; coal-tar colours ; in bleaching, dyeing, 

 and calico-printing ; in zinc-coating ; explosives ; 

 artificial silk; medicine, pharmacy, and photo- 

 graphy; and in the production of cold. But by 

 far the largest amount of combined ammonia is 

 used in agriculture. During the first decade of 

 this century the consumption of ammonium 

 sulphate rose from 125,000 to 322,000 tons, 

 whereas during: the same period the consump- 

 tion of sodium nitrate rose from 470,000 to 

 637,000 tons — a far less rapid rate of increase 

 than in the case of the ammoniacal salts, 

 which is bound to get still less as the Chile 

 beds approach exhaustion. .Although synthetic 

 methods of production of ammonia will play an 

 increasingly important part, it is practically cer- 

 tain that the principal source of ammonia and its 

 compounds will continue to be the nitrogen of 

 coal, and it is on the development of the coking 

 industry and on the recovery of the by-products 

 former!}' lost that the future of the ammonia 

 industry will depend. 



We heartily congratulate the veteran Professor 

 NO. 2443, VOL. 97] 



Emeritus of the Zurich Federal Techni( 

 Univ'ersity on the appearance of this admiral 

 work. Dr. Lunge deserves well of the indusl 

 which he has laboured so faithfully to sen 

 Every page of his treatise bears witness to I 

 zeal and painstaking care with which it has be 

 compiled and revised. The book, as hitherto, 

 admirably printed and excellently illustrat< 

 Indeed, no efforts have been spared by all cc 

 cerned to make it, what it unquestionably is. 

 far the most complete and authoritative work 

 have upon the important subjects of which 

 treats. T. E. Thorpe. 



MATERIALS OF CONSTRUCTION. 



The Structure and Properties of the More Co 

 mon Materials of Construction. By G. 

 Upton. Pp. v + 327. (New York: J. Wi 

 and Sons, Inc. ; London : Chapman and H; 

 Ltd., 1916.) Price 10s. 6d. net. 

 ''T^'HIS volume had its origin in a course 

 J- theoretical instruction preparatory to 

 laboratory course at Sibley College, Corr 

 University. The first part deals with the elas 

 theory and the determination of the properties 

 materials of construction, chiefly metals, by tt 

 ing. The ordinary rules connecting stress i 

 strain are discussed, but not in general the 

 struments used in testing. Rather more att 

 tion is given to the behaviour of materi 

 strained beyond the elastic limit than in treat! 

 on applied mechanics. Some of the stateme 

 are rather too'dogmatic. Is the author sure ti 

 in a tension test "the break must start at 

 outside and work inwards" (p. 36)? Engl 

 engineers will scarcely agree with the statem 

 that " there is not much excuse for the use of 

 Rankine or Ritter formulas " for columns. It ' 

 be new to them to learn that "live loads appl 

 without shock (for example, a rolling load crC| 

 ing a bridge at low speed) actually set up stresi 

 twice as great as a dead load of the '- 

 amount." The injurious effect of a live 

 without shock as compared with a dead loai 

 not that it increases the stresses, but tha 

 causes the " fatigue " effect. Of course, al? 

 produces shocks, which the author deals 

 separately. A live load is not a suddenly ap; 

 load. Nevertheless, this section is generally 

 and useful. The discussion of the cause of fai 

 failure is fuller than usual. No attempt is i 

 to give collections of results of tests. 



The second and rather larger part of the 

 deals with the internal structure of materials 

 , its modification by mechanical action, heat t 

 ment, etc. Is it true that the corrosion of 

 " takes place whenever the moisture in co: 

 with the metal becomes electrolytic either bv : 

 or alkalies " ? Freezing-{X>int and equilib jr 

 diagrams for lead-tin and iron-carbon alloys^r 

 described, and the constituents of cast-iron ,n 

 steel, austenite, pearlite, ferrite, cementite, c 

 are discussed verv fully. So also are the vari JO 



