502 



NATURE 



[August 17, 19 16 



question to put sufficient fin area on a dirigible 

 to render it directionally stable, but that it may 

 be controlled by comparatively small movements 

 of the rudder. This conclusion is also in agree- 

 ment with National Physical Laboratory results. 



Section 8, on svvept-back wings, and the follow- 

 ing section on the effects of dihedral angle, are 

 of considerable interest. The Dunne aeroplane 

 has excited much interest, and great claims have 

 been made for its stability. The results ot the 

 experiments in the American wind tunnel show 

 that the effect of swept-back wings on longitudinal 

 stability is nil, and that the degree of lateral 

 stability due to a sweep back of 20° is equally 

 well obtained by a dihedral angle of only 2i°, 

 while the latter is much better from a construc- 

 tional point of view. 



The last section deals with the critical flow 

 round flat discs normal to the wind. A mathe- 

 matical investigation is given for the case of non- 

 viscous irrotational motion, and it is shown that 

 the results are of the same order as those of the 

 experiments. The mathematical treatment is 

 obviously inadequate, since it ignores just those 

 qualities of the motion which affect its critical 

 change of flow : the viscosity and the rotational 

 motion. Similar problems have received attention 

 at the National Physical Laboratory, and it is 

 hoped to obtain, from actual photographs of the 

 motion in special cases, some information which is 

 not forthcoming from the hydrodynamical theory. 



On the whole, the results given in the Smith- 

 sonian publication are very interesting and afford 

 a useful independent comparison with those ob- 

 tained in our own country at the National Physical 

 Laboratory. The excellent agreement obtained 

 in the general conclusions of the present volume 

 with the previous work at the National Physical 

 Laboratory leaves no possible doubt concerning 

 the accuracy of experimental work of this descrip- 

 tion, or of the great utility of such experiments 

 in helping forward the design of all kinds of air- 

 craft. E. F. R. 



GEOFFREY W ATKINS SMITH. 



BY the death of Captain Geoffrey Watkins 

 Smith, of the Rifle Brigade, who was killed 

 by a shell in France on July 10 in a trench just 

 taken from the enemy, zoological science loses 

 one of the most promising and brilliant of its 

 younger adherents, and his many friends have to 

 regret a particularly lovable and gracious per- 

 sonality. Though only thirty-four years of age, 

 Geoffrey Smith, by the abimdance and originality 

 of his researches, had won for himself a secure 

 place in the scientific world, and his work was of 

 such a nature that each step gave promise of 

 further and more important discovery. It is not 

 possible within the present limits of space to give 

 more than a bare outline of his career and per- 

 formance. 



Geoffrey Smith, a son of Mr. Horace Smith, the 

 well-known Metropolitan magistrate, was born at 



NO. 2442, VOL. 97] 



Beckenham, Kent, on December 9, 1881. He 

 was educated at Temple Grove, East Sheen, and 

 afterwards at Winchester College, of which he 

 was a scholar, and in due course obtained a 

 scholarship at New College, Oxford. At Oxford, 

 working under the late* Prof. Weldon, he devoted 

 himself to the studies for which he had already 

 shown great aptitude in boyhood, and gained a 

 first class in the Honour School of Natural Science 

 in 1903. He proceeded to the Zoological Station 

 at Naples in the same year, and remained there 

 till 1905, when, having finished his monograph on 

 the Rhizocephala, the only monograph in the 

 Naples Fauna and Flora written by an Englishman, 

 he returned to Oxford to take up the duties of 

 demonstrator and lecturer in the University 

 Museum. In 1906 he was elected fellow and 

 tutor of New College in succession to Prof. G. C. 

 Bourne, and remained at Oxford till October, 

 1914, except for an excursion to Tasmania in 

 1907, the scientific results of which are published 

 in a volume entitled "A Naturalist in Tasmania." 



Geoffrey Smith's monograph on the Rhizo- 

 cephala, an excellent piece of zoological research, 

 has already been mentioned. As a result of his 

 voyage to Tasmania he made several solid contri- 

 butions to zoological science, publishing a memoir 

 on the Anaspidacea, living and fossil, in 1909, and 

 monographs on the fresh-water Crustacea of Tas- 

 mania and on the fresh-water Crayfishes of Aus- 

 tralia in 1909 and 191 2. But his chief and most 

 important work was his series of memoirs, eleven 

 in number, on the experimental analysis of sex, 

 issued from 1910 to 1914. In these essays, follow- 

 ing up clues suggested to him by his work on the 

 Rhizocephala, Geoffrey Smith attempted, and 

 attempted successfully, to probe the physiological 

 causes of the phenomena of secondary sexual 

 .characters. He showed that the assumption of 

 female characters by the parasitised male crab 

 Inachus is due to a profound change in metabolism 

 induced' by the parasitic Sacculina, and incidentally 

 demonstrated that the facts proved that the mak 

 is heterozygous and the female homozygous foi 

 sex. By a masterly association of ideas he 

 showed the close analogy between this physiologij 

 cal regulation in parasitised crabs and the phei 

 nomena of regulation which produce immunity r 

 bacterial diseases. He extended his observatioi 

 to bees, frogs, fowls, and pheasants, and succes 

 fully demonstrated similar physiological processt 

 in these animals, at the same time bringing acu- 

 critical experimental work to bear on certai 

 current theories of sex production. 



Much had been achieved, but much was let 

 unfinished when he accepted a commission in tl 

 New Armies in 1914. It is doubtful whether tl 

 work so brilliantly initiated can be carried on b 

 any other hand, certainly not with the same pro^ 

 pect of success. 



A final word must be said in praise of the ek, 

 gance of Geoffrey Smith's literary style, and thl 

 grace, humour, and courtesy with which he waj 

 wont to deal with attacks upon his work. 



