February 13, 1908] 



NATURE 



341 



its producing a gaseous mixture in which methane 

 plays an important part. 



The chapters upon gas lighting and the arrange- 

 ment of light for indoor and outdoor illumination are 

 excellent, whilst the chapter upon the legal relations 

 of gas suppliers, consumers, and the public should 

 prove of the greatest value to those who desire to gain 

 an insight into the intricacies of gas legislature. 



OUR BOOK SHELF. 



riie CaiUcrbury Puzzles and other Curious Problems. 



By H. E. Dudeney. Pp. xxiii+195. (London: W. 



Heinemann, 1907.) Price 3^. 6d. 

 The author of this little book is a well-known expert 

 in the invention and solution of puzzles. Those which 

 he presents to the reader are in the main entirely 

 original ; those which are not so are given in a new 

 dress. Puzzles can be made, as the author says, out 

 nf almost any materials, and most people are familiar 

 with specimens made out of matches, cards, coins, 

 &c. Generally speaking, they are in essence either of 

 .in arithmetical or geometrical character, and involve, 

 consciously or unconsciously, mathematical processes. 

 .\n inferior class it is difficult to deal with except by 

 some tentative process which involves no clear line of 

 reasoning; such, for instance, are certain dissection 

 probleins which aie of the nature of " patience," and 

 are not good exercises for the intellect. Mr. Dudeney 

 may be congratulated on having excluded these from 

 his book. 



It is no easy matter to invent a good puzzle; the 

 simplest method would be to modify or generalise a 

 known one ; a really new idea is not likely to come 

 from anyone who has not considerable knowledge and 

 power of observation. The author gives .shortly the 

 solutions of the puzzles without, in the large majority 

 of cases, explaining them. He recognises that the 

 non-scientific solver is generally satisfied with know- 

 ing the solution, and is not curious about reasons; 

 at the same time, he has known how to whet the 

 appetite of more intelligent and curious persons for a 

 knowledge of the principles which underlie the solu- 

 tions. As an example may be noted the puzzle called 

 "Lady Isabel's Casket." The square top of a box 

 was inlaid with a rectangular strip of gold 10 inches 

 by :J inch, and for the rest with square pieces of wood, 

 no two of which were of the same size. The puzzle 

 is to find out the size of the top of the box from these 

 data. In his solution of this difficult question, Mr. 

 Dudeney gives you the pattern, and states that the 

 nimiber, size, and order of the squares can be calcu- 

 lated direct from the given dimensions of the strip of 

 gold, and that there is only one possible solution. He 

 then leaves the mathematical reader with an interest- 

 ing if difficult nut to crack. 



The book is written in a popular manner, and is 

 copiously illustrated so as to impart as much human 

 interest as possible into the various questions. The 

 puzzles are of great variety, and will be found interest- 

 ing and alluring to persons of all kinds. 



Matter and Intellect : A Reconciliation of Science and 

 the Bible. By ."Xndrew Allan. Pp. vi+224. 

 (London : A. Owen and Co., n.d.) Price 5s. 

 This book has value from one point of view only; it 

 is a series of unscientific statements of the very first 

 water. " Now if we suppose that the oceans of the 

 earth are represented bv the bright sides of the discs 

 of the radiometer, and the continents by the dark 

 sides, we can understand how the sun attracts the 

 water and repels the land, thus causing the earth 



NO. 1998, VOL. yy] 



to rotate upon its axis." Even Mr. Allan's more 

 specific attempts to " reconcile Science and the 

 Bible " will provide the average reader with amuse- 

 ment more often than they will scandalise him. 

 " The serpent which tempted Eve was probably a 

 dinosaurian, and may possibly have been the Igua- 

 nodon, a reptile whicli ' must have walked temporarily 

 or permanently upon its hind legs,' thus presenting 

 a human appearance, to which its magnificent ski? 

 or robe of feathers would add considerable beautv. 

 Eve, therefore, seeing this human-like animal eating 

 of the tree, and suffering no harm, would readily for- 

 get the prohibition, and be tempted to try the fruit 

 for herself without any actual speech passing between 

 the two." 



Only one serious comment suggests itself when 

 one's capacity for laughter is exhausted. This extra- 

 ordinary work comes from a writer who has ability 

 enough often to express himself clearly and forciblv. 

 and quotes constantly from _ the pages of our more 

 august popularisers of science. The schoolmaster 

 admits at least a partial responsibility for the examin- 

 ation blunder. Is the blame here to be thrown 

 entirely upon the pupil? 



Lefons snr la Viscosity dcs Liquides et des Gaz. Bv 



Marcel Brillouin. Part i., Generalit^s. Viscosity 



des Liquides. Pp. vii + 228. Part ii.. Viscosity des 



Gaz. Caract^res gdn^raux des Theories mol^- 



culaires. Pp. 141. (Paris : Gauthier-Villars, 



1907.) Price 9 francs and 5 francs. 



Both the mathematical and experimental study of 



viscosity are admittedly of a high order of difficulty, 



and the author is to be congratulated on the clear 



and concise manner in which he has developed his 



subject. After summarising in the first chapter the 



early work on viscosity, the mathematical treatment 



of the subject is fully developed in the following four 



chapters. The second part of the first volume is 



devoted to a description of experimental work. Each 



of the principal memoirs is described and subjected 



to a careful criticism ; this part of the book is very 



complete, and is absolutely free from the tendency 



to ignore work done outside France occasionally met 



with in French standard works. 



In the second part the theoretical and experimental 

 study are taken together, the relations between the 

 viscosity and the dynamical theory of gases being 

 fully discussed. The concluding chapters contain a 

 general discussion of the molecular theories of 

 liquids and gases. 



The work as a whole is characterised by clear ex- 

 position, acuteness and fairness of criticism, and 

 completeness. It will doubtless take its place as the 

 standard work on viscosity. 



Aphorisms and Reflections. From the works of T. H. 

 Huxley; selected by Henrietta A. Huxley. Pp. vii + 

 200. (London : Macmillan and Co., Ltd., 1907.) 

 Price 2s. 6d. net. 

 To quote one of these aphorisms, " Time, whose tooth 

 gnaws away everything else, is powerless against 

 truth." There is garnered in Huxley's works so 

 much truth worth wide dissemination that we echo 

 heartily Mrs. Huxley's wish that this book will 

 attract the attention of many persons who are yet un- 

 acquainted with her husband's writings. We trust 

 also that this attractive volume, which can be carried 

 in the pocket, will serve to make men of science and 

 students turn oftener to the complete works of this 

 master of lucid expression, who proved conclusively 

 by his essavs that it is possible to describe scientific 

 achievements in a manner which will appeal to earnest 

 readers of all classes. 



