June 24, 1922J 



NATURE 



809 



rather rough-and-ready methods. Much of the chapter 

 on the aeroplane is out of date ; it is scarcely correct 

 to say that the air-pressure results for plane surfaces 

 can be corrected so as to apply to curved surfaces by 

 slight charges in the constants, and in any case there 

 are plenty of experimental data for giving a correct 

 account of cambered wings. The chapter on the 

 dynamics of aeroplanes is not very full, while a treat- 

 ment of the parachute by means of differential equations 

 is inserted for little reason, in a book which is not really 

 a mathematical treatise. In addition nearly three 

 of a total of less than 150 pages are occupied with 

 Glaisher's analysis of the motion of the balloon — with 

 the note that it has little practical value ! After the 

 chapter on ornithopters we get a short account of 

 dirigibles and the bodies of aeroplanes, etc. There is 

 also a brief account of stability. 



Some of the appendices are useful, although the 

 bibliography is disarranged. Foreign names are mis- 

 spelt, e.g. an umlaut on the " a " in Lilienthal. The 

 author has the ability to produce a real text-book on 

 aeronautics, but the present volume is disappointing. 



S. Brodetsky. 

 Die Pendulations-Theorie. Von Prof. Dr. H. Simroth. 



Zweite Aufiage. Pp. xvi + 598. (Berlin: Konrad 



Grathlein, 1914.) 13.50 marks. 

 Fired by a new view of the shifting of the polar axis 

 of the earth the speculative mind of a distinguished 

 zoologist, Simroth, conceived the idea of a relation 

 between earth oscillation and organic development. 



The merit of this oscillation theory of organic dis- 

 tribution was its reduction of the rise and spread of 

 organic forms to a single process in relation to recurring 

 secular change. Simroth assumed that the earth forms 

 an oscillation system of a peculiar kind, such that one 

 maximum line of stress runs north and south through 

 Norway, Germany, the line of elevation of the Alps, and 

 across the western Sahara, while the other companion 

 stress line passes through Bering Strait and the Pacific, 

 west of the American coast. Assuming also perman- 

 ence of the general configuration of the oceans and 

 continents, Simroth then makes his grand assumption, 

 which is that the evolution of genera has recurred 

 along the European line of maximum oscillation (which 

 is therefore the region of creative evolution) in response 

 to secular changes of environment. From this area of 

 distribution those forms that are primitive migrate 

 eastwards or westwards to areas of less disturbance, 

 whilst the progressive forms adapt themselves to the 

 cold of polar uplift or the warmth of equatorial depres- 

 sion. In this way Simroth accounts for the occurrence 

 of allied forms in widely separated parts of the world. 

 Beings are what they are and where they are, as a 

 " function " of the oscillation system. 



The new edition of this work does not remove the 

 difficulties of those who refuse to accept Simroth's 

 hypothesis. The new matter consists merely of 2)2> 

 pages appended to a reprint of the first edition and 

 contains no references to criticisms such as those of 

 Prof. G. C. Bourne (Proc. Zool. Soc. 191 1, pp. 802-805) 

 that refer to a fundamental objection — the secondary 

 nature of marine organisms. If Dr. Simroth has not 

 converted his fellow-zoologists, he is not likely to make 

 converts in other biological fields. Granted that we 

 have no simple alternative to his view, yet the assump- 



NO. 2747, VOL. 109] 



tions on which it rests are not in accordance with 

 modern geological opinion ; and if that is so, biological 

 speculation on such a weak basis is only misplaced 

 ingenuity. The earth as a system of stresses is likely 

 to prove a much more complex theme than the one 

 Simroth vaguely describes, while the relation between 

 maximum stress and biological progress requires far 

 more critical examination than he gives to it. 



F. W. G. 



Swiss Travel Almanac. Edited by the Swiss Tourist 

 Information Office. Summer Season, 1922. Pp. 1x2. 

 (Often, Switzerland : 0. Walter, Ltd. ; London : 

 Swiss Federal Railways, Regent Street, 1922). 

 This book is a reminder that Switzerland is ready once 

 more to become " the playground of Europe," and it is 

 especially an appeal to English visitors. The numerous 

 sigiied essays include one by Mr. A. Latt on " English 

 influences on Swiss intellectual life," recalling many 

 pleasant details of rapprochement in the seventeenth 

 and eighteenth centuries. Mr. Schaederlin writes finely 

 of the brave hardihood of alpine trees. Good and 

 readable as the essays are, the great charm of the book 

 lies in its illustrations. The well-known scenes of 

 tourist gatherings are relegated to the advertisement 

 pages at the end, and throughout this modestly styled 

 Almanac we are given an exquisite series of photo- 

 graphs, printed in brown, of " trees and woodlands " in 

 the Alps. Each of these appeals delightfully to the 

 naturalist, who will promptly consult the calendar and 

 the tables of exchange. G. A. J. C. 



Handbook of Commercial Information for India. By 

 C. W. E. Cotton. Pp. viii + 383. (Calcutta: Super- 

 intendent Government Printing, India, 1919.) 

 I rupee : 25. 

 Mr. Cotton's book is a useful volume which gives 

 in a condensed form, and well arranged for reference, 

 notes on all the principal exports of India, including 

 origin, district of growth, processes of preparation, 

 and conditions of export. It does not profess to be a 

 scientific work or in any sense a rival to larger and 

 more complete gazetteers of Indian products. It has 

 been compiled for traders, and with this end in view 

 notes on ports and commercial organisations are added. 

 Among the State departments connected with trade 

 we find a reference to the geological survey but none 

 to the Survey of India or to the Royal Indian Marine. 

 Does this imply that maps and charts have no bearing 

 on trade ? It is to be hoped that the demand for this 

 book will result in the publication of an annual edition. 



Das Problem der Genesis des Actiniums. Von M. C. 



Neuburger. Sonderausgabe aus der Sammlung chem- 



ischer und chemisch-technischer Vortrdge. Heraus- 



gegeben von Prof. Dr. W. 'Hertz. Band XXVI. 



Pp. iii-t-64. (Stuttgart: Ferdinand Enke, 1921.) 



5 marks. 



The author discusses the experimental work done on 



the origin and transformations of actinium, and the 



various hypotheses which have been put forward as to 



the successive changes in the actinium series. He 



concludes that at some stages, besides a-and /3-particles, 



particles of mass 3 and charge 2 are emitted. There 



is a detailed list of references, including some so recent 



1 as the year 192 1. 



