270 



NA TURE 



[March 2, 1922 



this book will be found equally suitable for the middle 

 forms of secondary schools. Containing, as it does, 

 excellent descriptions of the mode of working in wind- 

 mills, the steam engine, the internal combustion engine, 

 hydraulic, steam, and internal combustion turbines, 

 etc., it cannot fail to interest boys and to increase their 

 interest in their physical studies. There is enough, but 

 not too much, speculative matter included to stimulate 

 the thoughtful reader. We can thoroughly recommend 

 the volume as providing a useful addition to the 

 ordinary school course. 



An Introduction to the Physics and Chemistry of Colloids. 

 By E, Hatschek. (Text-Books of Chemical Research 

 and Engineering.) Fourth edition, entirely re- 

 written and enlarged. Pp. xiv + 172. (London: 

 J. and A. Churchill, 1922.) 75. 6d. net. 

 Mr. Hatschek's book is one of the best introductory 

 text-books on the subject in any language, and is widely 

 appreciated. The present edition has been rewritten 

 and enlarged, and embodies much of the recent work 

 on the subject. It should be in the hands of all 

 students of chemistry, and for this reason it is much 

 to be regretted that the price is not lower. 



The Manufacture and Uses of Explosives, with Notes on 



their Characteristics and Testing. By Dr. R. C. 



Farmer. (Pitman's Technical Primer Series.) Pp. 



xii-f-ii6. (London: Sir I. Pitman and Sons, Ltd., 



1921.) 2s. 6d. net. 

 Although interest in the military applications of 

 explosives has probably waned to a considerable extent 

 in most countries, it is perhaps not generally realised 

 what an important part these products of chemical 

 invention play in the arts of peace. The name of the 

 author of this small book is sufficient to guarantee the 

 accuracy of the information contained in it, and it is 

 only necessary to state that Dr. Farmer has compressed 

 into about a hundred small pages a surprising amount 

 of up-to-date material. The style is easy, but the 

 treatment is such that the book is far from being 

 merely a " popular " account of the subject : it is a 

 small encyclopaedia, which may be read with advantage 

 by all students of chemistry as well as by those more 

 directly interested in the manufacture and uses of 

 explosives. The very important source of sulphur at 

 Louisiana should have been mentioned on p. 37. 



Directive Wireless Telegraphy: Direction and Position 

 Finding, etc. By L. H. Walter. (Pitman's Technical 

 Primer Series.) Pp. xii-t-124. (London: Sir I. 

 Pitman and Sons, Ltd., 1921.) 2s. 6d. net. 

 It is now thirteen years since Bellini and Tosi read 

 their paper on "A Directive System of Wireless 

 Telegraphy " to the Physical Society of London. 

 Although Marconi and Fleming had previously done 

 good work on directive radio-telegraphy, it was this 

 paper that first showed British physicists how directive 

 signaUing could be obtained by using a fixed aerial 

 and only rotating a small coil of wire. The method^ 

 however, lay almost dormant until the war proved its 

 great practical utility. Mr. Walter was one of the 

 pioneers of the Bellini and Tosi system, and in the 

 volume under notice a resume is given of most of the 

 useful practical information available. The author 

 has utilised much of the theory recently published by 

 the Bureau of Standards and by the Signal Corps of the 



NO. 2731, VOL. 109] 



United States War Department. The mathematics 

 given is of the most elementary description, and will 

 be readily understood by every physicist and engineer. 

 We can commend this book. 



Fuel and Lubricating Oils for Diesel Engines. By W. 

 Schenker. Pp. xii -1-114. (London: Constable and 

 Co., Ltd., 1921.) 155. 



The title of this book is apt to convey a wrong 

 impression, as its contents in the main are of a general 

 character, and not specially devoted to Diesel engines. 

 There are three sections, the first of which deals with 

 the origin and preparation of various kinds of fuel oils, 

 with special reference to the varieties which may be 

 used for Diesel engines ; the second section treats 

 very briefly of lubricating oils ; whilst the third 

 consists of a description of the commercial tests applied 

 to these oils. The book would have been of greater 

 service to British consumers of oil had the author 

 included a fuller account of the methods of testing 

 and forms of specification used in this country instead 

 of confining himself to Continental practice in these 

 particulars. Thus Redwood's viscometer, the British 

 standard instrument, is dismissed in a dozen lines, 

 and Abel's flash-point apparatus is not mentioned. 

 Descriptions of other appliances are sometimes too 

 meagre, the bomb calorimeter being given only eleven 

 lines, whilst a purifying apparatus, illustrated on p. 66, 

 is entirely undescribed in the text. In spite of these 

 drawbacks, however, the book contains much useful 

 information of a practical kind. C. R. D. 



The Wonder Book of Science. By J. H. Fabre. Pp. 



287. (London : Hodder and Stoughton, Ltd., 



n.d.) 8s. 6d. net. 

 The object of Fabre in writing the series of essays 

 under notice was to impart general knowledge about 

 things that are familiar to the eyes, though not 

 necessarily to the understanding. The first seven 

 essays deal with insect-fife, and these are followed 

 by a number on birds, on some of the facts of plant- 

 fife, on the various forms of water and the appfication 

 of steam, on the elementary phenomena of electricity, 

 etc. These essays, which touch on so many subjects, 

 illustrate Fabre's method of arousing the interest of 

 young people in the phenomena around them. In all, 

 forty-eight essays are reproduced, but the name of the 

 translator does not appear. 



More Hunting Wasps. By J. H. Fabre. Translated 

 by A. T. de Mattos. Pp. viii + 376. (London: 

 Hodder and Stoughton, Ltd., n.d.) 8^. 6d. net. 

 Through the energies of the late Alexander de Mattos 

 a number of Fabre's most interesting studies in insect- 

 life have been rendered accessible to the general 

 reader in this country. The present volume consists 

 of fourteen chapters, which complete the essays in the 

 " Souvenirs Entomologiques " devoted to wasps. 

 The remainder have already been translated in two 

 earfier volumes entitled "The Hunting Wasps" and 

 " The Mason Wasps." Two of the essays in this book, 

 which form chaps. 2 and 10, have already appeared 

 in previous translations, while the remainder are 

 rendered in English for the first time. Most admirers 

 of the writings of the French savant will welcome the 

 appearance of this book and revel in the fascinating 



