3'4 



NA 7 URE 



[May 13, 1909 



calculations of their resultant thrust and centre of pres- 

 sure. But such an investigation is necessarily based 

 on hydrodynamical assumptions, and laboratory ex- 

 periments are required before any practical use can 

 be made of the conclusions. It must be remembered, 

 on the other hand, that questions of stability or in- 

 stability of particular types of machine can never be 

 decided by flights in which the human element has a 

 i^uiding influence. There is still work to be done with 

 models. On the practical side the committee will 

 have abundant experimental work in connection with 

 propellers, for the motion of a screw in fluid presents 

 complications which render any attempt at hydro- 

 dynamical treatment practically hopeless. 



It is scarcely surprising that the cry " too much 

 theory; fears that talk may injure work " finds its way 

 into the papers, and that some members of the Aero 

 Club put in a plea for the " practical man." The fact 

 seems, however, to be overlooked that the appointment 

 of this committee forms only part of a general scheme, 

 the practical side being provided by the War Office and 

 the Admiralty, both of w-hich departments have diri- 

 gibles in course of construction. A Parliamentary 

 committee embracing politicians of all parties is also 

 announced. 



It would be more correct, however, to describe the 

 present position of aeronautics in England as " too 

 much theorising and too little theory." Many papers 

 have found their way into aeronautical and other 

 periodicals, some of them full of algebraic symbols 

 and formula;, but an investigation is not necessarily 

 mathematical because it contains equations, and the 

 author is not necessarily a mathematician because he 

 employs them. Indeed, in many cases it is the " prac- 

 tical man " who revels in the excessive use and abuse 

 of formulae, and the mathematician and physicist who 

 would like to bring themselves into touch with prac- 

 tical problems are consequently deterred from reading 

 such literature. Moreover, there is a want of suit- 

 able journals for the publication of mathematical and 

 physical investigations bearing on aeronautics. They 

 would be rather out of place in physical journals which 

 deal more with such subjects as electricity and radio- 

 activity ; while any writer bold enough to try the 

 journals just mentioned would probably find himself 

 involved in a controversial correspondence, and would 

 learn that too much talk Aid injure work, eyiecially 

 as no good would probably come of his attempts to 

 enlighten his correspondents. 



Tlie need is thus becoming imminent for a clear 

 division of labour between the practical man and the 

 physicist, and if such a division should do no more 

 than make the practical man confine his attention 

 more exclusively to experimental work, much would be 

 gained, and his researches would be made more acces- 

 sible and useful. A division of a similar kind has now, 

 we are glad to learn, been arrived at between the 

 three leading societies devoted to aeronautics, namely, 

 the Aeronautical Society, the Aero Club, and the 

 Aerial League. The Aeronautical Society mainly 

 . exists for the purpose of promoting discussions on 

 aeronautical matters, and these consequently fall 

 within its province. The Aero Club undertakes the 

 development of aeronautics from the point of view of 

 s])ort. It desires to encourage men of means and 

 leisure to practise aviation and ballooning for the 

 pleasure they derive, and with the incentive of com- 

 peting for prizes. Finally, the Aerial League is to be 

 the paramount body in influencing public opinion in 

 the development of the subject from the point of view 

 of national defence. An agreement to this effect has 

 been drawn up and signed by the presidents of the 

 several societies. 



England's neglect of science has lost the chemical 



NO. 2063, VOL. 80] 



and optical industries, and in the automobile industry 

 France had a long §tart of us. It certainly does 

 appear evident that in regard to aeronautics at least a 

 serious attempt is being made to recover lost ground 

 in the field of international competition. 



G. H. Bryan. 



DR. GERALD F. YEO, F.R.S. 

 T^HROUGH the death of Dr. Gerald F. Yeo, 

 -'• Emeritus professor of King's College, London, 

 physiology has lost within a few weeks yet another of 

 those men who, within the last thirty years, materially 

 assisted in the creation of a British school of this 

 science, which, though of late development compared 

 with Continental schools, has grown with a rapidity 

 and vigour equalled only by the advances made on the 

 bacteriological side of pathology. In the foundation 

 of the Physiological Society, which at first included 

 hardly a score of members, Yeo took an active part, 

 being its honorary secretary for fifteen years from 

 1874 to 1890. 



Born in 1845, he was one of the sons of Henry 

 Yeo, J. P., of i-fowth, received his education at the 

 Dungannon School, then entered Trinity College, 

 Dublin, and obtained his medical degrees in 1867. 

 After some months of study in the hospitals of Paris, 

 Berlin, and Vienna, he returned to Dublin, where he 

 practised as a surgeon and taught anatomy until 1874. 

 In this year he was elected assistant surgeon 

 of King's College Hospital, and professor of 

 physiology in King's College, the histological 

 part of the work being undertaken by Groves 

 During this time, until his resignation in 1890, 

 Gerald Yeo, by his lectures, his research work, 

 and, in particular, by his strenuous advocacy of the 

 necessity of the experimental method in physiology, 

 as the chief of those methods by which material 

 advances in this science could alone be made, occupied 

 a prominent and influential position. In 1885 he pub- 

 lished a " Manual of Physiology," a book primarily 

 addressed to students, which gave a concise account 

 of the elements of this science. In the Arris and Gale 

 lectures delivered at the Royal College of Surgeons 

 in 1882 on " The relation of experimental physiology 

 to practical medicine," Yeo has probably given all the 

 essential arguments which have so repeatedly been 

 urged by those who claim that the sure basis of 

 physiological knowledge must rest upon experimental 

 work. An excellent account of the systeins of medicine 

 not dependent upon physiology compared with the 

 modern methods of rational treatment which depend 

 upon physiological and pathological knowledge, to- 

 gether with a most accurate account of the growth 

 of physiology, is to be found in these lectures. Among 

 other points, Yeo emphasised the paramount influence 

 of Haller, who, not only by his experimental work, but 

 by a comprehensive survey of what was then known 

 of physiology, may be said to have created this science, 

 a science conceived in the days of Galen, quickened 

 in the time of Harvey, but born only in the eighteenth 

 century. 



Gerald Yeo was elected a Fellow of the Royal 

 Society in 1890. His original work covered a some- 

 what restricted field. In 1S50 Helmholtz had meas- 

 ured the delayed time, or latent period, which precedes 

 the actual contraction of muscle by the method of 

 Pouillet. Instead of o'oi" for frog's muscle, Yeo, in 

 papers published by himself, and with Cash and 

 Herroun, succeeded, with the pendulum myograph, in 

 halving this value, which in its turn was finally 

 found to be too long by Burdon-Sanderson, _ who. 

 working with unweighted or slightly weighted 

 muscles, obtained o'o4" as the shortest time of delay. 



