NOTES 291 



Admiralty and War Office in Aerial Construction and Naviga- 

 tion," Lord Rayleigh naturally became its first President, an 

 office he continued to hold until a few weeks of his death. 



His work as President has been of the utmost value to 

 Aeronautics ; perhaps his greatest service has been his insist- 

 ence on the principle of similarity in defining the condition 

 under which model results obtained in an air-channel are 

 applicable to full scale work, and thus enabling results to be 

 obtained which have given to British Aircraft the superiority 

 they now enjoy. 



His death at this moment, when the question of future 

 Research and Education in Aeronautics is still unsettled, is no 

 small disaster. 



This list of investigations could, if space permitted, be almost 

 indefinitely extended, some naturally more important than 

 others, but all marked by the same characteristics — a clear 

 grasp of principles, a fearless courage in attacking difficulties, 

 and a firm determination to reach the truth. 



For some fifty years he worked. For many years past he 

 has been recognised and revered as the leader of English Physical 

 Science. The public knew him but little ; we who were proud to 

 be his pupils and his helpers realise only too sadly the greatness 

 of our loss. 



Professor Barkla (J. Nicol, B.A., iJ.Sc, Northern Polytechnic Institute) 



Professor Barkla, the recipient of the Nobel Physics Prize 

 for 1 91 7, is one of the most brilliant of the many distinguished 

 physicists who have come from the Cavendish Laboratory. 

 While there he investigated the influence of the nature of 

 wires on the speed of electric waves propagated along them, 

 but since then the whole of his work has been concerned with 

 X-rays, mainly with the various kinds of secondary rays 

 which they excite. So much did he dominate the subject, that 

 up till the application of diffraction methods to the problem 

 by Laue, Bragg, and Moseley, the history of X-ray discovery 

 was practically a history of the discoveries of himself and his 

 pupils. 



Leaving the Cavendish Laboratory in 1902, he returned to 

 his old University, Liverpool, as Oliver Lodge Student, and 

 remained there as demonstrator and lecturer until 1909, when 



