December 8, 1923] 



NA TURE 



847 



activities of the Foulerton professorship. Now at this 

 present anniversary, the pleasurable privilege falls to 

 me of announcing the appointments of Prof. A. Fowler 

 and Mr. G. I. Taylor to the Yarrow professorships. I 

 may be allowed here a brief reference to their work. 

 I follow the alphabetical order of their names. Prof. 

 Fowler is known the world over as a spectroscopist 

 whose researches have been of the greatest value to 

 astronomy, to physics, and to chemistry. Entering 

 on science first as a pupil of, and then as an assistant 

 to. Sir Norman Lockyer, his earlier researches were, 

 at that provenance made natural, astrophysical in 

 kind, although the special technique which he de- 

 veloped was a technique of methods purely laboratory. 

 He achieved extraordinary success in identifying lines 

 observed in stellar spectra with lines which he was 

 able to reproduce in the laboratory ; he was able thus 

 to assign the lines to their chemical origin. For 

 example, the origin of the bands which dominated the 

 spectra of what were then described as stars of 

 Secchi's third class had been a mystery for many 

 years. Fowler was able to show that they were due 

 to titanium oxide. He accounted for many of the 

 bands in the sun-spot spectrum by showing that they 

 "belonged to magnesium hydride. Again, he made 

 an interesting study of the spectra of comets. The 

 spectrum of the head had been observed by Donati in 

 1864 and had been fully studied by Huggins and 

 others. It remained for Prof. Fowler to make a study 

 •of the tail spectrum of comets. He noticed first that 

 the observed spectrum coincided with one which had 

 been obtained in the laboratory arising from an im- 

 purity in low-pressure hydrogen. Finally, after much 

 ■effort and laborious work, this spectrum was found to 

 originate in carbon monoxide. 



While these are perhaps some of the more striking 

 of Prof. Fowler's successes in the region of astro- 

 physics, he has also done a great deal of highly useful 

 work in adding to our knowledge of the spectra of 

 known terrestrial substances. Special mention may 

 perhaps be made of his study of the spectrum of 

 •scandium, which proved to be important both in 

 solar prominences and in sun-spots ; of magnesium, 

 in which he discovered new series of spectral lines ; of 

 strontium, in which he added several lines to the 

 already known triple series ; and of the active modi- 

 fication of nitrogen discovered by the present Lord 

 Rayleigh. 



At the time that these investigations were carried 

 out, there was no reason to suppose an immediate 

 future of practical importance for the results obtained, 

 but with the advent of Bohr's theory of atomic 

 structure, they have been found to provide exactly 

 the material required for full discussion of the new 

 theories of atomic structure, and for the acquisition 

 of new positive knowledge as to the details of atomic 

 mechanism. Perhaps his success of most striking 

 general appeal has been his direct experimental proof 

 that the so-called i'-Puppis series of hydrogen originate 

 from helium and not from hydrogen at all. This 

 result incidentally provided a striking confirmation of 

 '*ohr's theory of the origin of spectra. 



In this field of research Prof. Fowler stands un- 

 rivalled. Recently he has been examining the 

 changes which take place in the spectra of elements as 

 one electron after another is remo\'ed ; the results 

 obtained are of fundamental importance. His last 

 paper, on the " Spectrum of Trebly Ionised Silicon," 

 win still be fresh in the minds of many of our 

 fellows. 



Branches of physical science other than those bene- 



titing by Prof. Fowler's work have formed the field of 



search of the Society's other Yarrow profe.s.sor, Mr. 



. I. Taylor, namely, mathematics, engineering, and 



L;cophysics. Mr. Taylor started his scientific life as 



NO. 2823, VOL. I 12] 



an applied mathematician, and the Society is still 

 fortunate in receiving from him frequent mathe- 

 matical papers on hydrodynamical themes. Before 

 the advent of Mr. Taylor to this field, it was almost a 

 foregone conclusion that the results of mathematical 

 research in a large part of hydrodynamics would not 

 be confirmed by experiments ; Mr." Tavlor has opened 

 an era in which experiments and analysis give con- 

 firmatory results. From abstract hydrodynamics he 

 was led to research in practical problems of geophysics 

 and meteorology. He has a distinguished record in 

 aeronautical science, dating from the time when, 

 acting as ]\Ieteorological Adviser to the Air Force, he 

 was led to study the motions of the air, the causes and 

 effects of eddies and the complicated phenomena to 

 which these give rise. The application of much of his 

 work to problems connected with aircraft is very 

 direct. As the result of mathematical calculations he 

 designed a parachute possessing many advantages in 

 practice ; quite recently he has published an import- 

 ant theoretical investigation as to the manner in 

 which the forces on a model aeroplane in a wind- 

 channel are affected by the eddies set up at the 

 channel's mouth. Some contributions by him have 

 proved of high value to the theory of the propeller. 

 He has taken a leading part in the development of a 

 theory which goes far to account for the forces of an 

 aeroplane in terms of the circulation round it, and the 

 series of trailing vortices shed from its wings. 



Mr. Taylor has been equally successful in the 

 application of mathematics to engineering problems. 

 In collaboration with Mr. A. A. Griffiths, he was 

 the first to utilise the fact that the equations which 

 determine the torsion of an elastic bar are identical 

 with those representing the displacement "of a thin 

 membrane stretched over a hole of suitable shape 

 when slightly distorted by uniform pressure. By 

 micrometric measurements of the distortion of such 

 a membrane, he was able to deduce the torsion 

 stresses inside a bar of specified cross-section, a 

 procedure having practical applications of the 

 greatest importance. 



In the last Bakerian lecture delivered before the 

 Society, Mr. Taylor, in conjunction with Miss Flam, 

 studied the strains in a single crystal of aluminium 

 when stretched to breaking point, using a most 

 ingenious combination of micrometric measurements 

 and X-ray analysis. In this way he was able to 

 trace the internal motions in the crystal and to 

 explain the striking difference between the fracture 

 of a bar of ordinary metal and that of a single crystal, 

 such as he examined. In this, his most recent work', 

 he has opened up a field which promises to be of 

 far-reaching importance to the science of the strength 

 of materials, and, I venture to think, of great practical 

 value to the working engineer. 



The record of both of our new professors gives 

 every justification for hoping that in the unfettered 

 freedom of the Yarrow professorships they may find the 

 opportunity for still more ample fulfilment of brilliant 

 work. It is fortunate that they will both continue 

 their researches in the laboratories from which their 

 outstanding work has issued in the past, and of the 

 traditions of which their reputations already are, 

 indeed, a part. 



Finally, may I in general terms return once more 

 to summarise that leading motive, which has actuated 

 the launching of these new professonships. Our 

 universities and other scientific institutions have 

 been wont — indeed in many cases by force of circum- 

 stances are compelled — to regard teaching as the 

 primary occupation of professoriate and staff and 

 to envisage their occupation by research as merely 

 secondary to their occupation in routine teaching. 

 The Society has inverted quite deliberately that 



