; 4 6 



NATURE 



[October 26, 191 1 



contrary, he must be familiar with the scientific side 

 of electrical engineering generally, so that all he 

 needs is a kind of finishing-touch in his technical 

 education which will make his work in a particular 

 direction more efficient. 



In the book under review this finishing-touch is 

 given in the matter of testing alternating-current 

 machinery and apparatus. In all there are 127 tests 

 described. In each case the description begins with 

 references to the literature on the subject; then is 

 stated the object of the test, and after that comes a 

 short dissertation on "theory and method." In some 

 cases the authors add suggestions as to the collection 

 of data, the plotting of curves, the extension of the 

 test to somewhat different cases, and questions as to 

 the effect of varying some of the conditions of the 

 standard test. All this is extremely useful to the 

 advanced student, but only to him. A beginner could 

 only blindly follow instructions, and could not grasp 

 the true scientific meaning of the thing he is doing. 



It is perhaps natural that in a book written, in the 

 first instance, for the students of an American uni- 

 versity, methods and tests devised by American engi- 

 neers should receive more attention than equally good 

 work done in Europe ; but when the authors christen 

 old and well-known methods by American names, they 

 go a little further in the direction of local patriotism 

 than is warranted. As an instance, I take the Joubert 

 method of taking the E.M.F. and current curves 

 of an alternator. After describing the original method 

 (by the way, the authors spell the name Jobert), where 

 a ballistic galvanometer is used, they describe a 

 "Bedell method" and a " Mershon method." Both 

 these are nothing else than the Joubert method 

 as it has been used for a generation in Europe. In 

 the former, the ballistic galvanometer is replaced by a 

 condenser and electrostatic voltmeter, and in the other 

 by the well-known device of a potential slide and 

 D.C. voltmeter. 



Again, some methods which originated in Europe 

 are either ignored or mentioned without reference to 

 the inventor. Thus the well-known Sumpner method 

 of testing transformer efficiency under full load whilst 

 only the lost power need be supplied from outside, is 

 given without Dr. Sumpner's name being mentioned. 

 These are, however, minor blemishes; the important 

 thing is that the authors have given us a valuable 

 collection of accurate tests which can be carried out 

 with such apparatus as may reasonably be supposed to 

 be available in the test-room of a modern electrical 

 engineering works. 



GlSBERT KAPP. 



EDIBLE FATS. 

 Edible Fats and Oils: their Composition, Manu- 

 . and Analysis. By \Y. H. Simmons and 

 ! A. Mitchell. Pp. viii+150. (London: Scott, 

 Greenwood and Son, 1911.) Price ys. 6d. net. 



1IT-VT enters into human food in a considerable 

 J variety of forms, and the modern tendency is 

 to increase the variety. Whilst in earlier days the 

 NO. 2 19 1, VOL. 87] 



animal products — butter, lard, and dripping — were the 

 principal fats consumed as foodstuffs, in recent times 

 a large number of vegetable oils and fats have also 

 been brought into use for the same purpose. New oils 

 and "butters" have been found; improved processes 

 of purification have been introduced ; and the industry 

 has become one of notable magnitude. It has greatly 

 augmented, and therefore cheapened, the supply of 

 lat available for human consumption. 



What the authors have done in the volume before 

 us is to collect from various sources particulars of the 

 edible fats and oils now in use, and arrange them in 

 a convenient form for reference. These particulars 

 include short descriptions of the origin, manufacture, 

 physical and chemical characters, and methods for the 

 analysis of the various products dealt with, which 

 fall into the four main classes : butter, lard, butter- 

 substitutes, and salad-oils. From the scope of the 

 book, however, the descriptions are necessarily often 

 meagre. They would serve well as an introduction 

 to the subject, or for easy routine work in examining 

 the various articles, but would require to be suj'f '1. - 

 mented in the more difficult cases which are mel 

 with in practice. 



A somewhat curious analogy is recalled by the name 

 of Mege-Mouries, mentioned in connection with the 

 origin of butter-substitutes. The production of beet 

 sugar, which has now reached very large dimensions, 

 is said to owe its early development to the encourage- 

 ment given it by Napoleon I. in his policy of making 

 France independent of foreign supplies. Now, just 

 as this variety of sugar has supplemented and partly 

 ousted cane sugar, so margarine has supplemented 

 and partly supplanted butter; and the introduction 

 of margarine we owe to investigations fostered by 

 Napoleon III. 



M. Mege-Mouries was commissioned by this 

 monarch to find, if he could, a cheap but wholesome 

 substitute for butter, to be used by the French poor. 

 He eventually succeeded in doing this, utilising the 

 softer portions of beef suet for the purpose. Later, 

 owing to scarcity of this ingredient, it became m 1 1 s- 

 sary to include a proportion of vegetable oils, and this 

 has led to a greatly extended consumption of such 

 oils. The margarine industry is now quite a con- 

 siderable one, the annual importations into this 

 country alone being valued at more than two millions 

 sterling. 



If we consider the effect which the production of 

 beet sugar and of margarine has had, first in aug- 

 menting the supply of foodstuffs for the human race 

 in general, and secondly in benefiting the agricul- 

 ture of the particular countries engaged in the pro- 

 duction ; and if we further remember that this effect, 

 so far as can be foreseen, is destined to continue, 

 from year to year and generation to generation, is 

 it altogether paradoxical to suggest that the two 

 Napoleons' claims to remembrance might justly be 

 based less upon their military operations than upon 

 1 heir vicarious attentions to sugar and margarine? If 

 iln swards have not been beaten into ploughshares, 

 they have perhaps been beaten by them. 



C. S. 



