December 8, 1923] 



NA TURE 



825 



written by the manager of the Krian estate, is virtually 

 a text-book of sugar-planting under the conditions 

 obtaining in Java. In addition to its utility as a 

 practical guide, it should prove of interest from the point 

 of view of comparative agriculture, since, in Java, local 

 circumstances call for an intensive form of cultivation 

 which does not obtain in all sugar-growing countries. 

 The fundamental principles of sugar cultivation, 

 however, are the same in all producing regions, and 

 they are clearly set out by the author. There are two 

 sections of the book. The first part, which is intro- 

 ductory, deals with cultural conditions in Java, and 

 affords a discussion on soils, manuring, and the botany 

 •of the sugar-cane ; while part two furnishes a practical 

 account of the cultural methods adopted on the Krian 

 estate, including operations down to the harvesting 

 and transport of the cane, and deals also with certain 

 aspects of estate administration. The book is excel- 

 lently illustrated with photographs and coloured plates. 



The Theory of Experimental Electricity. By W. C. 

 Dampier Whetham. (Cambridge Physical Series.) 

 Third edition. Pp. xi-H349. (Cambridge: At the 

 University Press, 1923.) 12s. 6d. net. 



To students with a limited knowledge of mathe- 

 matics who desire a sound theoretical basis on which 

 to build we can heartily recommend this book. 

 The author writes in a most interesting and convinc- 

 ing way, and gives an excellent preliminary introduction 

 to the latest electrical theories, as well as a clear 

 account of the apparatus and methods used in an 

 •electrical laboratory. He points out that according to 

 the electron theor\% matter is an electric manifestation, 

 and so the mass of a body must be explicable as electric 

 inertia. The electric inertia of a magnetic field can 

 be represented as due to the motion of electric tubes 

 of force in the luminiferous ether. In this way electric 

 inertia is in its turn " explained " as " mechanical 

 inertia " of the hypothetical substance invented to 

 ■enable our minds to form a rational picture of other 

 physical phenomena. The author points out that, 

 in a certain sense, simplification is thus attained. All 

 natural phenomena are referred to the properties of 

 the ether. Nevertheless, the mystery is but changed. 

 We may have explained matter in terms of ether, 

 l)ut how are we to explain ether ? The book closes 

 with this question unanswered. 



Statistical Method. By Prof. Truman L. Kelley. 

 (Text-book Series.) Pp. xi + 390. (New York : 

 The Macmillan Co. ; London : Macmillan and Co., 

 Ltd., 1923.) iSs. net. 



This volume by an educationist should be of great 

 >ervice to those who use statistical methods in any 

 •leld, since it provides a summary of nearly all, if 

 not all, the methods which have been proposed for 

 measuring relationship. This seems likely to be its 

 chief use, but it includes also a discussion of frequency 

 distributions and of Pearson's set of curves, with 

 chapters on index-numbers and other special applica- 

 tions. The study begins with data already collected, 

 l)Ut the introductory chapters outline the principles 

 of tabulation and graphical representation. Although 

 problems are suggested in several chapters, the book 

 can scarcely be regarded as a text-book for beginners, 



NO. 2823, VOL. 112] 



being very condensed in many parts, with few worked 

 examples, but rather is a critical survey. In the 

 treatment of correlation much use is made of a symbol 

 for Ji -r^ as " coefficient of alienation." Appendices 

 supply a list of symbols used, a bibliography — which 

 is not up-to-date as regards editions of books — and 

 an extended table of deviates of the normal curve. 

 The index is small but useful. 



Eastern England : some Aspects of its Geography, with 

 Special Reference to Economic Significance. By John 

 Bygott. Pp. XV + 358. (London : G. Routledge 

 and Sons, Ltd., 1923.) 65. net. 

 In this book the author has attempted with a large 

 measure of success to make a geographical study of 

 agricultural England, devoting his attention to East 

 Anglia and Lincolnshire. The study is comprehensive 

 and thoroughly geographical. In no aspect of the 

 subject does Mr. Bygott lose touch with the effects 

 of location, relief, soil, and climate, and he considers 

 the region in the past as well as the present. The 

 volume rises far above the rank of the ordinary text- 

 book as a serious contribution to the regional geography 

 of the British Isles. There is a little overlapping in 

 places ; occasionally condensation would not be amiss ; 

 and it might facilitate the use of the book if some of 

 the statistical matter was arranged in tabular form ; 

 but these are all minor points, and do not materially 

 detract from a useful volume. The numerous sketch- 

 maps are not the strongest part of the book. 



R. N. R. B. 



The First Days of Man : as Narrated quite simply 

 for Young Readers. By F. A. Kummer. (The 

 Earth's Story, i.) Pp. 293. (London : Hodder 

 and Stoughton, Ltd., 1923.) 75. 6d. net. 



Although this little book does not call for extended 

 notice, it is worth mention as a type of educational 

 work which is more common in the United States 

 than in Great Britain. After a preliminary chapter 

 dealing with cosmic evolution, it gives the main 

 outline of the development of civilisation up to the 

 end of the Stone Age in a logical order and an attractive 

 form suitable for quite young children. In the whole 

 it keeps fairly closely to accepted fact and theory, 

 while avoiding the more formal methods usually 

 adopted in the elementary introductions to the results 

 of archaeological study which have hitherto been 

 offered to the British public. 



An Introduction to Mining Science : a Theoretical and 

 Practical Textbook for Mining Students. By J. B. 

 Coppock and G. A. Lodge. (Longmans' Technical 

 Handicraft Series.) Second edition. Pp. xi + 252. 

 (London : Longmans, Green and Co., 1923.) 4s. 



This book provides a sound and interesting course in 

 elementary science, from the point of view of the needs 

 of miners. It is clearly written, and is well printed and 

 illustrated. The experiments are carefully described, 

 although it is questionable whether a large class should 

 prepare small specimens of nitroglycerine, and then 

 pour them down the sinks, as directed (p. 186). In 

 the experiment on p. 120, a bit of " compo " tubing 

 is less likely to do damage than gla.ss. The technical 

 matters are well explained, and the book will be useful. 



