SIE G. G. STOKES, BART,, ON THE RONTGEN RAYS. 25 



which we are not at all prepared for ; but I see by the clock 

 that I must not detam you any longer on speculations- 

 [Applause.] 



Postscript. 



This " different sort of explanation " is one between which 

 and the supposition of periodic vibrations of excessively high 

 frequency my mind has for a long time oscillated. In the 

 above lecture I gave the preference to the latter ; but sub- 

 sequent reflection leads me strongly to incline to the former. 

 I hope before long to develope fully these views elsewhere ; 

 meanwhile suffice it to say that I am disposed to regard the 

 disturbance as non-periodic, though having certain features 

 ill common with a periodic disturbance of excessively high 

 frequency. 



The Right Honourable Lord Kelvin, G.C.V.O., F.R.S.— Mr. 

 President, my Lord Chancellor, ladies and gentlemen ; I must 

 first express, on my own account, great regret that I -was unable 

 to arrive in time to hear the whole of the Annual Address. 

 Judging from what I have heard, I am able to appreciate how 

 great has been my loss in not hearing the whole. I do not, how- 

 ever, feel at all unable to ask you to accord a most hearty vote of 

 thanks, for what T have heard is more than enough to justify all I 

 would say in support of the motion which I have to put before you. 

 Sir George Stokes has given a most interesting and important 

 description of one of the greatest discoveries of this century. 

 The subject upon which he has spoken — in fact all that he has 

 touched upon — is full of contentious matter. The scientific 

 world lias been greatly agitated in regard to the Rontgen 

 phenomena since the beginning of January. Almost every 

 sentence that the President has put before us is strongly in 

 opposition to a great deal that has been published by many ex- 

 ceedingly able men, both mathematicians and experimenters. I 

 have listened with great pleasure, satisfaction and comfort to Sir 

 George Stokes's declarations. If I had doubts myself, my doubts 



