February 6, 1913] 



NATURE 



617 



remain for all time one of the great classics of 

 science, a source of perpetual delight and inspira- 

 tion to all true philosophers. He who drinks at 

 such fountains can never grow old, for the clear 

 waters that flow therefrom are the true elixir of 

 the human spirit. F. G. Donnan. 



PHYSICAL AND CHEMICAL CONSTANTS. 

 Tables Annuelles de Constantes et Donnees 

 Numeriques de Chimie, de Physique et. de 

 Technologie. Vol. i., annee 1910. Pp. xxxix + 

 727. (Paris : Gauthier - Villars ; Leipzig : 

 Akademische Verlagsgesellschaft m.b.h. ; 

 London : J. and A. Churchill ; Chicago : 

 University of Chicago Press.) Price 245. net 

 (cloth); 215. 6d. net (paper). 

 ■^T^HIS somewhat ponderous volume is the first 

 X of a series of the same character it is pro- 

 posed to publish annually. It comprises a com- 

 pendium of those constants of physics, chemistry 

 and technology which result from researches 

 published during the year 191 o. The volume 

 would appear to bear to Science Abstracts and the 

 Abstracts published by the Chemical Society about 

 the same relation as a dictionary to an encyclo- 

 paedia. It is compiled under the auspices of an 

 international committee, on which Dr. Wilsmore 

 is the British representative, aided by a number 

 of collaborators and abstractors, the general secre- 

 tary of the committee and editor-in-chief being 

 Dr. C. Marie, of Paris. 



To review and criticise such a work is not easy, 

 and it would be manifestly unfair to treat the 

 volume like a book of tables, looking in it for 

 information on definite subjects and commending 

 or blaming according as one found or did not find 

 what was required. We have some doubt, how- 

 ever, whether any considerable number of workers 

 will be willing to purchase some large book of 

 constants, such as the well-known " Landolt and 

 Bornstein," or the late Mr. Castell-Evans's 

 Chemical-Physical Tables, and use the present 

 publication as an appendix to the same. 



The volume is printed on good paper, but a good 

 deal of space seems to have been wasted, making 

 the book extremely bulky. On the whole, it seems 

 fairly easy to ascertain from it whether, during the 

 year it covers, any additions were made to our 

 knowledge in any of the branches dealt with. Pure 

 chemistry, and in particular organic chemistry, 

 occupies a large share of the 727 pages composing 

 it, and it is probably to the chemist rather than 

 to the physicist that it will be of most use. Like 

 most other books of tables, it is quite uncritical in 

 character, and we doubt the utility of a bare state- 

 ment, such as, for example, that found on p. 

 NO. 2258, VOL. 90] 



227: "Cuivre pur — variation de la resistance en 

 pour cent a 20° = o'3938," with no details as to 

 the state of the metal or why the constant quoted 

 differs so widely from the accepted value; but, 

 nevertheless, we think that on the whole the work 

 of the abstractors seems to have been con- 

 scientiously done. 



The English of the book savours in places of an 

 old-fashioned French exercise book ; the English 

 translations of French terms used have a look in 

 some instances of having been dug out of a dic- 

 tionary of the Early Victorian period. Throughout 

 the indexes and in some other places German, 

 English, French, and Italian equivalents are given 

 for titles, etc., but in the body of the work the 

 language used is generally French. Better in- 

 dexes to the present volume than those which are 

 given are needed, and are promised in the 191 1 

 issue. J. A. Marker. 



TWO BOOKS ON NAVIGATION. 

 (i) Nautical Astronomy. By W. P. Symonds. 

 Pp. 130. (London : J. D. Potter, 191 2.) Price 65. 

 (2) The "Newest" Navigation Altitude and 

 .Asimuth Tables for Facilitating the Determina- 

 tion of Lines of Position and Geographical 

 Position at Sea. Second edition. By Lieut. R. 

 de Aquino. Pp. xlix+ 176 + v* + 36*. (London: 

 J. D. Potter, 191 2.) Price io.<r. 6d. net. 



AUTICAL astronomy is simply the 

 application of spherical trigonometry 

 to the problem of ascertaining the latitude and 

 longitude at sea by observations of the heavenly 

 bodies ; as also the errors of the compass. To 

 a student acquainted with spherical trigonometry 

 it is only necessary to give the figure showing 

 the data available, and the result required, to 

 enable him to make the necessary calculation. 

 Mr. Symonds gives the figures and also some 

 trigonometrical formula;, as do all other books, 

 or nearly all others, which treat of navigation and 

 nautical astronomy, but his figures are badly 

 drawn, especially Fig. 2 on p. 8. 



It is in the practical application for obtaining 

 the data required for calculating a ship's position 

 that Mr. Symonds fails : — (i) No stress is laid 

 on the importance of obtaining the latitude and 

 longitude simultaneously. This can always be 

 done by star observations at twilight, in the morn- 

 ing and evening, when the horizon is sufficiently 

 clear and the stars are plainly visible. It can 

 often be done in the daytime when either Venus 

 or Jupiter passes the meridian between sunrise 

 and 9 a.m., or between 3 p.m. and sunset. 

 (2) No stress is laid on the refraction of the sea 

 horizon, which can only be eliminated by taking 



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