52 



NA TURE 



[November 16, 1905 



but this opinion of ours may possibly arise from the 

 difficulty we have felt in fathoming his arguments. 

 There is an originality of statement about them which 

 often makes it impossible to decide hurriedly as to 

 whether they are right or wrong. For example : — 



" Electricity is not to be confounded with the 

 electric spark — they are the direct opposites of each 

 other. Electricity is a force of attraction which 

 brings particles of matter into contact ; the electric 

 spark is the kinetic energy produced by the action of 

 the electric force through the available distance, and 

 has a dispellant effect upon the particles. By the 

 conservation of energy the electric force ceases to act 

 when the spark is produced. The potential is then 

 converted into kinetic energy. This affords a con- 

 clusive reply to the theory, adopted by some eminent 

 authorities, that electricity and light are identical. 

 Light is a form of heat and has always a dispellant 

 effect upon the particles of matter. It is therefore 

 the direct opposite of electricity, which is a force of 

 attraction." 



This is certainly not all wrong. The question is 

 how much of it is right? To those readers who are 

 attracted by the above extract we recommend the two 

 hundred and thirty-seven pages of this volume. 



(2) Just as in the work reviewed above the depend- 

 ence of forces upon position is made the universal law, 

 so here the essential identity of all forces is sought for 

 in a kinetic view of matter. 



All phenomena of attraction are explained, and can 

 be reproduced by the simple rotation of a screw or 

 turbine in water and in air. The turbine is pre- 

 sented as the universal motor which gives rise to 

 molecular attractive forces and the phenomena which 

 accompany them. The author claims to assume 

 nothing besides the propulsive motions produced by 

 rotations of molecular turbines, and congratulates 

 himself on the rare good fortune that everyone can 

 understand the effects of such rotation. 



A number of experiments with ventilating fans are 

 described ; the author then wanders off into a com- 

 parison of a magnet with a living being, and a con- 

 sideration of the position of man in the universe. 



It is a commonplace to suppose that scepticism is 

 the beginning of belief; the author's creed is accom- 

 panied by the usual doubt as to the validity of many 

 of the conclusions of modern science. The value of 

 his criticisms can be measured by his objections to 

 the recognition of the essential identity of light and 

 Hertzian waves. He disposes of the argument which 

 rests on the identity of velocity of the two phenomena 

 bv saying that all waves produced in the ether, of 

 whatever nature they may be, must, in fact, have the 

 same velocity, since the velocity of a wave depends, 

 not on its form, but only on the elasticity and density 

 of the medium of transmission, which in this case 

 is the ether. 



We cannot look upon this book as a serious con- 

 tribution to scientific literature, but we readily admit 

 that there are analogies between the effects of the 

 motions which the author describes and other physical 

 phenomena ; and if these were systematically described 

 a very interesting volume could be made. But there 

 is so much here that is merely fanciful that we must 

 advise anyone who reads it to read it with caution. 

 NO. I 88 I,- VOL. -]i\ 



OUR BOOK SHELF. 



A Descriptive Handbook of Architecture. By Martin 

 A. Buckmaster. Pp. xvi+iS8. (London: George 

 Routledge and Sons, Ltd., n.d.) Price 3s. bd. net. 



This is a little book which is intended to help those 

 to whom architecture is a subject of ever-increasing 

 interest. The author refers to a subject which Mr. 

 Banister Fletcher has already brought forward 

 prominently in the preface to " The History of Archi- 

 tecture " and in a paper read before the University 

 Extension Guild, namely, the inclusion of the study 

 of historical architecture in a liberal education. It 

 certainly seems that, owing to the ease of travel, the 

 use of photography and other causes, a knowledge 

 of the elementary principles and forms of the various 

 types of architecture might well be expounded to the 

 senior forms of educational institutions, and this way 

 of interesting the rising generation in matters which 

 appertain to everyday life and observation would tend 

 largely to increase interest in matters artistic and 

 practical. 



Concerning the book under notice, much cannot be 

 expected for the low price at which it is published, 

 and it would probably have been better had the author 

 dealt with one period of architecture, and have done 

 that thoroughly, rather than have taken up so large 

 a field. It has resulted in an essay which is 

 " scrappy," and from which we are afraid the atten- 

 tive student will gather very little of much use to 

 him. 



One or two points call for revision. Why is 

 " mediaeval " architecture made to end at 1090 when 

 most people hold that it commences about that time? 



Plate iiia. is merely an enlargement of part of 

 plate xviii., and might be omitted. Some of the 

 illustrations are very poor ; that on p. 20 would lead 

 the student to believe that the Temple of Theseus 

 and the Parthenon had suffered from an earthquake 

 since we saw them last spring! 



The ground range of the columns to the Colosseum 

 is not Doric, dentils are wrongly spelt on pp. 25 

 and 27, and the Temple of Zeus, Athens, is given 

 another name on p. 28. The giving of exact dates 

 for each period, and the printing at the top of each 

 page, are sure to mislead the student ; for no style can 

 be truly confined within a period of such exactitude as, 

 say, 1377-1547. an d the student should be warned 

 against such an attempt. 



The line illustrations are of an amateurish descrip- 

 tion, and plates viii. and xi. should be re-drawn. 



Plate xliv. seems to be a copy of a plate in a well 

 known history, though this is not acknowledged. 

 The division of early Christian architecture into 

 Roman and Byzantine is likely to confuse the student, 

 as Roman is always considered historically as pagan 

 architecture. 



Proceedings of the London Mathematical Society. 



Vol. ii. Pp. xx + 490. (London: Francis Hodgson, 



"OS-) 

 The present volume of Proceedings, though the size 

 of the page has been changed, and larger type is used, 

 contains about the same amount of subject-matter as 

 its predecessors. It affords evidence that the publi- 

 cation of researches in higher mathematics still 

 receives the same care and attention which it has for 

 many years past obtained at the hands of the small 

 body of workers who mostly travel up on Thursdays 

 by the 2.15 train from Cambridge to attend the meet- 

 ings in Albemarle Street with their friends. It con- 

 tains interesting obituary notices of Mr. Ronald 

 Hudson and Dr. Pirie. Among the contributors we 



