July 28, 1892 J 



NATURE 



291 



some more detailed information on a variety of points. 

 Nevertheless, we consider that this book is a useful ad- 

 dition to electrical literature, and must be of the utmost 

 use to students in showing the difficulties which have to 

 be encountered in designing a plan of central station 

 working. The general reader will also be much interested 

 in learning something more of the meaning of the work 

 which he sees being carried out at present in the streets 

 of many of our towns. Should the book chance to fall 

 into the hands of any members of electric lighting com- 

 mittees of Municipal Corporations, it will do a vast 

 amount of good, by opening their eyes as to the number 

 of problems that have to be considered in their dealings 

 with different contractors, each generally wedded to a 

 special system. It is to be hoped that this book will teach 

 them that, in trying to act as consulting engineers without 

 the special training necessary, they are not serving the 

 best interests of the towns they represent. Altogether, 

 " Electric Light Cables " is a useful addition to the litera- 

 ture of electrical engineering, and the absence of too 

 many technicalities will make it popular with a large 

 class of readers. 



OUR BOOK SHELF. 



Distribution de l' Electricity. I. " Installations Isoldes." 

 II. " Usines centrales." Par R. V. Picou, Ingenieur 

 des Arts et Manufactures. (Paris : Gauthier-Villars, 



1892.) 



These two small volumes are portion of a series belong- 

 ing to " L'Encyclopddie scientifique des Aide-Mdmoire," 

 published under the direction of M. Ldautd, Member of 

 the Institute. The second volume is the only one which 

 calls for remark. It deals with the methods, well known 

 in England, of distribution of continuous and alternating 

 currents and systems of high and low pressure. The in- 

 formation given concerning the multiphase and rotary 

 current systems is very scanty and quite out of propor- 

 tion to the other matters treated of. The reader will 

 naturally look for an account of the method employed for 

 the transmission of power from Lauffen to Frankfort, but 

 he will find no information of any practical service. The 

 author, however, gives a short discussion of the difficulties 

 that must be surmounted if arc and incandescent lamps 

 are to be installed on a circuit fed by a triphaser and 

 three wires. 



Information is given concerning the working of some 

 of the principal existing central stations, and there is a 

 useful bibliography. 



Popular Readings in Science. By John Gall, M.A., 

 LL.B., and David Robertson, M.A., LL.B., B.Sc. 

 (Westminster : Constable and Co., 1892.) 

 This forms the second volume of Constable's Oriental 

 Miscellany of original and selected publications, and is 

 intended to form the basis of a general course of instruc- 

 tion in science, suited to the requirements of the pupils 

 in Indian schools who are preparing for matriculation at 

 the University. The authors lay no claim to originality, 

 but have exercised a judicious choice in the selection of 

 subject matter. The first chapter deals with meteorology, 

 special prominence being given to Mr. Blandford's re- 

 searches on the climate of India. Then follow chapters 

 on the vegetable kingdom, evolution, both in its bio- 

 logical and chemical aspects, mimicry, the nebular hypo- 

 thesis, tidal evolution, energy, the spectroscope, molecular 

 forces, and Bacteria. A reference to the meteoritic hypo- 



NO. 1 187, VOL. 46] 



thesis would make the chapter on the nebular theory 

 more complete. The authors have wisely contented them- 

 selves with descriptions of theories and plain matter-of- 

 fact statements. The book is very readable, but at times 

 somewhat technical. It would, however, be improved 

 by the addition of more diagrams, though it may be that 

 more can safely be left to the imagination of the Oriental 

 than the Western mind. The narrative style which 

 has been adopted by the authors will make the book 

 acceptable to general readers who are anxious to make 

 acquaintance with modern science. 



Geometrical Deductions^ Book II. By James Blaikie 

 and W. Thomson. (London : Longmans, Green, and 

 Co., 1892.) 



This treatise is intended to afford a systematic course of 

 training in the art of solving geometrical problems. The 

 basis of the system which the authors have employed is 

 to be thoroughly recommended, being both logical and 

 simple. The book is divided into sections, each of 

 which consists of three parts. In the first a model de- 

 duction is fully worked out to illustrate the method of 

 solution ; then follow similar deductions with their 

 figures, and occasional hints ; while, lastly, the student 

 is left to himself to solve the problems without any such 

 aid. This principle is maintained throughout the entire 

 book, so that a student should be able to obtain a good 

 working knowledge and should also to a great extent be 

 quite rid of a teacher. 



The Appendices will also be found very useful, as they 

 contain the enunciations of the propositions in Euclid's 

 second book and of standard theorems and loci, together 

 with a set of miscellaneous deductions covering the range 

 of Euclid's first two books. 



LETTERS TO THE EDITOR. 



yiht Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of N atu re. 

 No notice is taken of anonvnious communications. ] 



B.A. Procedure. 



The coming meeting of our ancient and venerable institution, 

 the British Associa.tion for the Advancement of Science, will doubt- 

 less be a large one, as the beauties of Edinburgh are sure to 

 tempt many to attend, and may therefore give opportunity for 

 discussion on a subject of fundamental importance — the future 

 well-being of the Association and the means of retaining it as 

 an object of veneration on account of the services which it 

 is rendering and not merely on account of those which it has 

 rendered. 



It is beyond question that there are many who have long been 

 dissatisfied, and who are of opinion that B.A. procedure is not 

 in harmony with the times. Moreover, to speak plainly, many 

 of us feel that the " tripper " element has become too predomin- 

 ant, and that the credit of science will suffer if a large number 

 of persons be permitted, year after year, to make pleasant holi- 

 day, "supported by voluntary contributions," under the pretence 

 of advancing science, while the number of true workers whose 

 reputation alone upholds the claim of the Association to public 

 recognition is but small. 



In the great majority of instances the reading of papers on 

 technical questions in the sections has become little less than a 

 solemn and dreary farce played to almost bare benches ; and it 

 is only in exceptional cases— such as Section A affords — that a 

 small and devoted body of true believers worship at an inner 

 shrine without regard to the general public, and are thus able 

 among themselves to do work of high value to science. 



The B.A. should exercise an influence in two directions— it 

 should advance scientific knowledge among scientific workers ; 

 and it should aid the general public in understanding and appre- 

 ciating scientific work, its methods and results. It may effect the 



