Di^CEMBER 24, 19 14] 



NATURt-: 



-^49 



paratus. The definitions of acids, bases, and 

 salts are novel, but altogether bad. If they 

 <:ould be taken literally, they would include 

 amongst the bases such diverse substances as 

 oxygen, phosphorus, potassium permanganate, 

 sugar, alcohol, camphor, benzene, toluene, formic 

 acid, oxalic acid, since all these substances can 

 " react with an acid, giving water as one of the 

 products." Amongst the "salts" one would find 

 chlorine, phosphoric acid, oxalic acid, ethyl 

 acetate, ethylene, ether, camphoric acid, nitro- 

 benzene, benzoic acid, carbon monoxide, and 

 carbon dioxide, since each of these may appear in 

 the guise of " substance, other than water, pro- 

 duced by the reaction of an acid and a base," 

 as defined in the opening sentences of the 

 ■chapter. 



(5) Mr. Bausor's two books on chemical calcula- 

 tions may be commended on the ground that the 

 problems bear a very close resemblance to those 

 that would be met with in the actual experience 

 of a chemical worker. No further commendation 

 is needed except to say that the range of sub- 

 jects and the working out of typical problems are 

 alike satisfactorA-. The only improvement that 

 may be suggested is to the effect^ that greater 

 interest would be aroused and more useful in- 

 formation imparted incidentally if the author had 

 drawn more freel}' on numerical data taken from 

 classical experiments, such as those of Berzelius 

 and of Stas, together with more modern experi- 

 ments by Morley, Richards, Morse, Guye, and 

 others. 



(6) Dr. Knox's monograph on the fixation of 

 nitrogen includes a great deal that has become 

 very familiar in recent years, but the subject has 

 been treated in a very satisfactory way. In 

 addition to the well-known details of the Birke- 

 land-Eyde process, ample space is devoted to the 

 theory of the operations and to the many scientific 

 experiments that have been made to elucidate 

 them. The section on the ammonia equilibrium 

 is particularly welcome, in view of the fact that 

 this method of fixing nitrogen has been exploited 

 in the technical Press to a much smaller extent 

 than the processes described in the other two 

 sections of the book. It is not usual to jjermit 

 any detailed study of technical processes in an 

 elementary course of chemistry, yet nothing but 

 good would result if this little monograph were 

 added to the curriculum of such a course ; the 

 problems with which it deals are so important 

 and the underlying theories are so illuminating 

 that they might well be used to add an element 

 of romance and a new interest to the oft-told 

 ;story of elementarj' inorganic chemistry. 



T. M. L. 

 NO. 2^::; 6, VOL. Q4.1 " 



OUR BOOKSIIEU- 



By F. W. Turner and D. G. 

 114. (New York: John Wiley 



Pattern-making. 

 Town. Pp. V 

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

 Ltd., 1914.) Price 45. 6d. net. 

 This little book is intended for young pattern- 

 makers, and presents a general sur\ey of the 

 most suitable materials, the special tools, and the 

 fundamental processes of the trade, together with 

 the relations of the pattern-shop with the allied 

 departments, viz., the drawing office, the foundry, 

 and the machine shop. The pattern-maker is 

 principally concerned with the foundry, and 

 throughout the book we find clear and concise 

 descriptions of moulding processes, well-illus- 

 trated, together with discussions of the sometimes 

 conflicting requirements of the moulder and pat- 

 tern-maker, and explanations of the compromises 

 which have to be adopted. In recent years the 

 development of machine tools, both in the foundry 

 and in the pattern-shop, has altered considerably 

 the art of pattern-making and also the stock of 

 hand-tools composing the private equipment of the 

 artisan. 



The book contains many interesting devices 

 which have been developed by American workmen 

 for special purposes, and in this respect will be 

 found to be of considerable interest even to older 

 pattern-makers in this country. A special word 

 may be said regarding the illustrations in the 

 book ; these are excellent, both as regards the 

 selection of typical examples and also clearness of 

 drawing and reproduction. 



We can confidently recommend the book to 

 young pattern-makers and others connected with 

 engineering, not that it will make them good 

 pattern-makers — experience alone will produce this 

 result — but on account of the broadening of views 

 which is sure to be acquired during the perusal of 

 its pages. 



Foundations: a Sliort Text-book on Ordinary 

 Foundations, including a brief description of 

 the methods used for Difficult Foundations. By 

 Prof. M. A. Howe. Pp. vii+iio. (New York : 

 John Wiley and Sons, Inc. ; London : Chapman 

 and Hall, Ltd., 1914.) Price 55. 6J. net. 

 Ix this book the author has treated in an elemen- 

 tary manner both the fundamental principles in- 

 volved in the design of foundations and also 

 standard methods of carrying out the actual work. 

 Special treatment is given of the footing courses 

 of structures, these being considered apart from 

 the foundation propjer. The Rankine theory is 

 adopted for the permissible bearing pressure on 

 soils, and a modified form of Rankine 's fo'rmula is 

 given ; there is a brief discussion of the precau- 

 tions which must be considered in dealintj with 

 various descriptions of soil. Several different 

 methods of construction in the footing courses are 

 given, such as concrete, brick, reinforced con- 

 crete, grillage, I Ijeams, and cantilevers ; these are 

 clearly described, and the student will have no 

 difficulty in following the methods of calculation. 

 A feature of the book consists in worked-out 

 examples of each case ; these will be found to be of 



