562 



NATURE 



[January 29, 1920 



he gives about fourteen pages (it was originally an 

 hour's lecture) to each of his subjects, and in that 

 short compass manages to bring before his audi- 

 ence the picture of a complete personality, clearly 

 distinguished from all the rest, and an adequate 

 idea of the nature of his scientific work. There 

 are a few minor inaccuracies, but our only quarrel 

 is with the title, for of the ten (Maxwell, Tait, 

 ■Rankine, Kelvin, Stokes, Airy, Adams, Whewell, 

 Babbage, John Herschel) not all can strictly be 

 said to be physicists. However, this is the fault of 

 the editors, not of the author, for the book is post- 

 humous ; and we would not willingly part with any 

 of the ten ; Babbage, the least physical, is perhaps 

 the most interesting. We are glad that neither of 

 the authors is ashamed to tell again the old 

 stories ; the younger generation must learn them 

 somewhere, and they could not be better told. But 

 did Freddy Tait really drive that golf ball? 



Concerning Prof. Bower's "Hooker," little also 

 need be said. It is scholarly, as we should expect 

 from its author, but, alas ! it is not interesting. 

 Prof. Bower has not, we think, managed to con- 

 vey to his readers why either Hooker or his work 

 was great. But some failures in an enterprise of 

 this kind there must be ; let us be thankful for the 

 successes. Everyone ought to read Mr. Macpher- 

 son's and Mr. Macfarlane's books, and make all 

 his acquaintances do the same. N. R. C. 



OVR BOOKSHELF. 



The Aviation Pocket-book for 1919-20. A Com- 

 pendium of Modern Practice and a Collection of 

 Useful Notes, Formulae, Rules, Tables, and 

 Data Relating to Aeronautics. By R. Borlase 

 Matthews. Seventh edition, revised and en- 

 larged. Pp. xxiv+536. (London: Crosby 

 Lockwood and Son, n.d.) Price 12s. 6d. net. 

 The impression received from a perusal of this 

 book is that the author's chief aim in life is the 

 classification of data, and that the value of the 

 data is of secondary importance. The elaborate 

 arrangements which make the pocket-book suit- 

 able for cutting up to fit a number of standard 

 loose-leaf books or card index cabinets are valu- 

 able in proportion to the value of the information 

 contained on its leaves. Since many of the tables 

 are inaccurate, it would appear that the author 

 holds a different view. 



The resistance of the wings of an aeroplane is 

 stated to have an average value equal to 15 per 

 cent, of the total for the aeroplane, whereas it is 

 probably never less than 50 per cent., and certainly 

 greater than 60 per cent, in the case of modern 

 aeroplanes at economical flying speeds. In the 

 case of engines, the variation of power with height 

 is represented in a table which is seriously wrong 

 when the height exceeds 10,000 ft. Even the tabu- 

 lated characteristics of a standard atmosphere do 

 not agree with those used in British aeronautics. 

 NO. 2622, VOL. 104] 



The weight per horse-power of engines to be used 

 in preliminary design is given too high ; the maxi- 

 mum of 200 h.p. there quoted is insufficient to 

 cover the needs of aviation in 1920. 



One also wonders why some twenty pages are 

 devoted to tables and formulae referring to flat 

 plates, whilst four suffice for what the author 

 describes as "modern wings." These instances of 

 defective data suggest that the author would have 

 been better employed in correcting his data than 

 in developing a classification system. It is for- 

 tunate that much of the data is taken solidly from 

 the publications of such bodies as the British 

 Engineering Standards Committee and the Royal 

 Aeronautical Society, and it is as a very full index 

 to these works that the pocket-book appears to 

 find a justification for its existence. 



A Manual of the Electro-Chemical Treatment of 

 Seeds. By Dr. Charles Mercier. Pp. viii+134. 

 (London : University of London Press, Ltd., 

 1919.) Price 3s. 6d. net. 



This book is essentially a personal statement," 

 and the reviewer is under the serious disad- 

 vantage that the distinguished author died soon 

 after writing it, and can no longer make the 

 rejoinder that a suitable critique would inevitably 

 call forth. It deals entirely with a proprietary 

 process for the treatment of seeds before sowing. 



The process consists in placing the seeds in a 

 2i-5 per cent, solution of sodium or calcium 

 chloride through which an electric current is pass- 

 ing, then taking them out and drying them. Five 

 gallons of solution are needed per bushel of seed, 

 and 8 watts of electricity per gallon. The drying 

 is carried out by means of a blast of air heated to 

 100° F. The seed must then be sown as early as 

 passible, as the effect lasts only a month. 



Extraordinary increases in crop are claimed, 

 and some astonishing photographs are reproduced 

 in the book. Very few actual figures of crop 

 weights, however, are available, and the author 

 did not deal adequately with the awkward fact 

 that the method had not been a success at the 

 experimental stations where treated seed supplied 

 by the proprietors had been tested. No useful 

 purpose would, however, be served by referring 

 further to such points as these, for Dr. Mercier 

 cannot reply. 



The New Hazell Annual and Almanack. By Dr. 

 T. A. Ingram. Pp. 873. (London : Henry 

 Frowde, Hodder and Stoughton, 1920.) Price 

 65. net. 



On p. 206 of this useful annual we find a list of 

 the Nobel prizemen for physics, chemistry, medi- 

 cine, literature, and peace from 1901 onwards, 

 together with a note on the Nobel foundation. 

 This is an example of the kind of information 

 which we expect to find in " Hazell," but not in 

 other general annuals ; and we are rarely disap- 

 pointed. The sections on scientific and educational 

 subjects are full of facts concisely presented, and 

 the whole volume rightly claims a place upon every 

 reference bookshelf. 



