426 



NATURE 



[February io, 1910 



OVR BOOK SHELF. 



A Primer of Statistics. By W. Palin Elderton and 



Ethel M. Elderton. Pp. viii + 86. (London: A. 



and C. Black, 1909.) Price is. 6d. net. 

 In his Herbert Spencer lecture of 1907, Sir Francis 

 Galton outlined a suggested course of " Object- 

 lessons in the Methods of Biometry," adapted to per- 

 sons with no mathematical knowledge. The course 

 was to consist of five lessons, the first to introduce 

 the learner to the idea of variability and the median, 

 the second to deal with the scheme of distribution 

 (theogive curve), the third with deviations from the 

 median, the fourth with frequency curves (including 

 the arithmetic mean and the standard deviation), and 

 the fifth with correlation. 



The present little volume owes its genesis to this 

 suggestion of Sir Francis Galton, who contributes a 

 short_ preface, and it follows very much the lines 

 he laid down, with the addition, however, of a chapter 

 on probable errors. The style is for the most part 

 very simple, and the volume should be of real ser- 

 vice to biological students and others who desire 

 to obtain a general idea as to the meaning of the 

 terms used in modern statistical methods. A few 

 statements seem, however, to be open to criticism. 

 The student ought not to conclude that "shells 

 possess a mid-length (or median) which is con- 

 stant in different samples" (p. 6) when he has 

 only examined two samples. It is hardly correct to 

 state that "when the difference between two means 

 exceeds three times the probable error, then it is con- 

 sidered to be certain that the difference is significant " 

 (p. 79); it is merely moderately likely. Finally, while 

 It is true that the theory of errors of sampling "de- 

 pends on the assumption that the things dealt with 

 have been taken at random " (a word which does not 

 appear to be defined), we cannot agree with the 

 unqualified statement that "the collection of statis- 

 tics in any other way is sheer waste of time," nor 

 that "it is far better ... to take 5000 or 6000 cases 

 at random . . . than to take 50,000 which are 

 specially chosen" (pp. S2-3) ; the contrary, indeed, 

 may often be the case. 



In the first chapter, we also suggest, it would be 

 better to use longer series as illustrations; Figs. 2, 

 3, and 5_, especially, hardly suggest the true form of 

 the " ogive " to anyone who is not prejudiced bv a 

 wider experience than the readers of this book 'are 

 assumed to possess, and scarcely iustify the statement 

 made on p. 6 as to the form of the curve. A second 

 edition of this little volume is sure to be called for 

 as it fills a distinct gap in statistical literature, and 

 the points mentioned might receive consideration. 



All About Shi t,s and Shipping: a Handbook of 

 Popular Nautical Information. By Commander R 

 Dowling^ R.-N.R. With a Preface by Commander 

 ^y. F. Caborne, C.B., R.N.R. Third edition, re- 

 vised. Pp. xyi+429. (London : Alexander Moring, 

 1-td., 1909.) Price S';. net. 



This is the third edition of a handbook of popular 

 nautical information. It has been compiled by a sea- 

 man, and is intended largely, if not chiefly, for the 

 use of general renders. At the same time, it contains 

 much which will interest sea-sroing folks. It claims 

 to be corrected up to date, but in some sections this can 

 hardly be said to have been accomplished. This is 

 particularly true of information given in regard 

 to_ warships. For instance, the short chapter dealine 

 with submarine boats does not sro beyond the " A " 

 class, whereas last year the "D" class had been 

 reached. The latest developments in battleships are 

 NO. 2102, VOL. 82] 



better dealt with, but the inevitable compression which 

 has to be accepted in a book of very moderate size 

 dealing with a great mass of miscellaneous informa- 

 tion has resulted in meagre descriptions of types of 

 ships both in war fleets and in mercantile marines. 

 No pretence at originality is made by the author. 

 His task has been one rather of collection and com- 

 pression of information, and the attempt is, on the 

 whole, fairly successful. The book would prove a 

 pleasant companion to people taking long sea-voyages 

 or short pleasure cruises who desired to identify 

 vessels of different nationalities and different mercan- 

 tile lines of steamships, or who wished to understand 

 something of the technique and vocabulary of the sea- 

 faring profession. 



In an\f future edition of the book Commander 

 Dowling would confer a favour upon his readers if 

 references were given which would enable anyone so 

 desiring to turn to larger and authoritative works 

 bearing on the very great number of subjects treated, 

 many of which are necessarily described by him in 

 barest outline. It must not be understood that Com- 

 mander Caborne fails to acknowledge his indebtedness 

 to others for facts and information ; the only fault 

 is that no systematic references are made to places 

 from which information has been drawn. If he 

 introduced another appendix dealing with the biblio- 

 graphy of ships and shipping, it would certainly be 

 welcomed by those who take an interest in maritime 

 affairs, and desire fuller information than can be 

 expected to be found in a pocket book. 



Van Nostrand's Clicmical .Annual, igoq. Second 

 issue. Edited by Dr. J. C. Olsen. Pp. xii + s8o. 

 (London : Constable and Co., Ltd.) Price i2x. 6d. 

 net. 



The first edition of this " .\nnual " was published in 



1907, and was reviewed in Nature of January 23, 



1908. The second issue, w'liich has recently come to 

 hand, has been increased in size by some eighty pages, 

 and contains a considerable amount of new matter, 

 including a table of the physical constants of the 

 alkaloids, by Dr. A. Seidell, and a similar table for 

 the essential oils, by A. E. Seeker, who has also re- 

 vised the tables on fats and oils. Prof. Parr's recently 

 calculated table of the densities of carbon dioxide has 

 been inserted, and also a table showing the melting 

 points and the composition for a number of fusible 

 alloys. 



The table of gravimetric factors and their 

 logarithms has been entirely re-calculated on the basis 

 of the international atomic weights for 1909, which 

 involved an unusually large number of alterations. 

 The review of chemical literature and the list of new 

 books give the titles of all important publications 

 which have appeared since the first issue. 



The publishers have, we think, been well advised 

 in abandoning the attempt to present a fresh issue 

 every year. Although important alterations in the 

 recognised constants are made from time to time, 

 the majority hold good for long periods, and there 

 cannot be many chemists who would care to pur- 

 chase a fresh volume of tables every year for the sake 

 of the limited number of alterations that may be 

 made. It appears, indeed, to the w-riter that the 

 interval between successive issues might with advan- 

 tage be extended to four or five years, so as to avoid 

 burdening the bookshelves of the purchaser with a 

 number of volumes in which the same tables are of 

 necessity repeated again and again. The attempt to 

 combine tables of reference with reviews of current 

 literature can only be expected to achieve success 

 through a compromise of this character. L. 



