152 



NATURE 



[October 23, 1919 



luncheons to which the commission was ruthlessly 

 exposed, the number of speeches which they were 

 forced to make, and the other at least equal 

 number to w-hich they were compelled to listen, 

 one is impressed by the fact that this academic 

 gfroup " did their bit " in a very real sense. One 

 also wonders whether the present demand for a 

 reduction in the hours of labour could not be 

 directed towards a change in the customs of after- 

 dinner speaking, resulting in a great conservation 

 of the nervous energy of the world. It is to be 

 hoped that the journey which is here so grace- 

 fully described is but the first of many, perhaps 

 less formal but more leisurely, which will be 

 undertaken by academic and scientific men of both 

 countries. It would be a pity if the greater 

 intimacy and understanding, which war conditions 

 have undoubtedly brought about between the men 

 of science of England and America, should for 

 any cause be allowed to lapse. C. E. M. 



OUR BOOKSHELF. 



The Statesman's Year-book. Statistical and 

 Historical Annual of the States of the World 

 for the Year 1919. Edited by Sir John Scott 

 Keltic and Dr. M. Epstein. Fifty-sixth Annual 

 Publication. Revised after Official Returns. 

 Pp. lii-t-1476. (London: Macmillan and Co., 

 Ltd., 1919.) Price 185. net. 



One turns to the new volume of this ever-welcome 

 annual with considerable interest in view of the 

 present fluid condition of international affairs. 

 The coloured map shows the condition of Europe 

 in June of this year, the accession to political 

 sovereignty of Iceland, Poland, and Czecho- 

 slovakia is recognised by their treatment in new 

 and separate sections, and the introductory pages 

 contain the League of Nations Covenant, a sum- 

 mary of the peace terms to Germany, and a con- 

 tinuation of the diary of the war. The Iceland 

 section summarises the consequences of the Act 

 of Union of November, 1918, which makes the 

 connection between Denmark and Iceland, in 

 other than certain temporary arrangements, 

 entirely due to the fact that both States have the 

 same King. Although it has not been possible to 

 include statistics regarding the dismembered 

 Austro-Hungarian Empire, various estimates have 

 been included — e.g. the new Austrian Republic 

 has a population of some ten millions, of whom 

 90 per cent, are Germans ; the probable population 

 of Yugo-Slavia is twelve to thirteen millions. 

 There are brief summaries of the results already 

 achieved by British administrators in Mesopo- 

 tamia, and of the newly independent kingdom of 

 Hejas. 



The Boys' Own Book of Great Inventions. By 



Floyd L. Darrow. Pp. ix + 385. (New York : 



The Macmillan Company ; London : Macmillan 



and Co., Ltd., 191 8.) Price 125. 6d. net. 



This book contains a popular and interesting 



account of the more important inventions of the 



last hundred years. One chapter is devoted to the 



NO. 2608, VOL. 104] 



gyroscope ; six to telegraphy and telephony, with 

 and without wires ; two to aviation ; and one each 

 to the submarine ; the steam engine ; petrol, oil, 

 and gas engines ; the use of machinery in agri- 

 culture ; the development of electricity ; the 

 evolution of artificial illumination ; fife and high 

 temperatures ; some notable achievements in 

 chemistry ; the story of iron and steel ; and 

 Galileo and the telescope. The treatment is un- 

 usual. The author in most cases first appeals to 

 general interest by describing practical achieve- 

 ment. He then gives an account of the theory, 

 and concludes with a few experiments which the 

 boy may perform for himself. 



The style is good, the information is accurate, 

 and the explanations are generally clear. The 

 experiments are to the point, but, appearing as 

 they do detached from the descriptions of the 

 apparatus and process, they appear to be scrappy 

 and unsatisfactory. Many of them are quite un- 

 necessary in the case of a boy who is doing science 

 at school, and to a boy who is not they would not 

 all prove helpful. We prefer description f nd 

 explanation, even where that involves experiment, 

 to be more closely associated. 



The value of some of the half-tone blocks is 

 much reduced by printing two or three on a page, 

 which renders them indistinct. 



Apart from these minor defects, the book is 

 first-rate, and will form an excellent gift for a 

 boy who is interested in scientific achievement. 



E. C. 

 Interpolation Tables or Multiplication Tables of 

 Decimal Fractions. Giving the Products to the 

 Nearest Unit of All Numbers from 1 to 100 by 

 001 to 0-99 and from i to 1000 by 0001 to 

 0-999. By Dr. Henry B. Hedrick. Pp. ix-(- 

 139. (Washington : Carnegie Institution of 

 Washington, 1918.) 



The simplest description of these tables is to 

 say that they give such results as 0302 x 441 = 133 

 with the certainty (barring errors in the tables) 

 that the third digit in the product is correct. 

 Taking out such a product from the tables is an 

 easy operation, requiring very little time; prob- 

 ably, with practice, the use of the book would 

 be as expeditious as that of an ordinary slide- 

 rule, and the results more trustworthy. 



Various other ways of using the tables are 

 explained in the introduction. The editor also 

 gives interpolation formulae, and worked applica- 

 tions to astronomy, etc., in which these tables 

 are used. 



This publication appeals to a large body of com- 

 puters and scientific workers, and affords another 

 instance of the wise enterprise of the directors of 

 the Carnegie Institution. They have already 

 earned the gratitude of arithmeticians by their 

 tables of primes and factors, and they are doing 

 a public service by thus undertaking the cost 

 of printing works at which no ordinary publisher 

 would look for a moment. 



The printing and arrangement of the tables 

 seem to be all that could be desired. 



G. B. M. 



