vi.] PROFESSORIAL L1FI. 157 



competency. At the beginning of 1834 he was candidate 

 for a different office ; and I think that I then attempted 

 to take a step in his favour as before. 



1 In the years from 1830 to 1835 I was much employed 

 on physical optics, in its two divisions of diffraction and 

 polarization. 



' Professor Forbes took great interest in these subjects, 

 and 1 had much correspondence with him. 1 had arranged 

 for my lectures at Cambridge a rather rude machine for 

 ! at ion between plane-polarized light and 

 circularly or elliptically-polarized light, and Professor 

 Forbes entered heartily into this matter, and requested 

 me to furnish him with a duplicate of my machine. 



* The undulatory theory of light was then struggling 

 into existence, or at least into reception ; and the clear 

 understanding and hearty support of it by Professor 

 Forbes must have contributed materially to its successful 

 establishment in the locality with which he was more 

 imnu'd lately connected. 



* In 1S35 the question was raised by me of the esta- 

 blishment at this Observatory of a system of continuous 



. ations. I had from the first the advantage 

 of frequent correspondence with Professor Forbes on the 

 various points entering into consideration. 



1 In 183G Professor Forbes communicated to me, as 

 one of the fiivt persons, I believe, his splendid disco^ 

 of tho polarization of radiant ! 



' Prom ; iii- lime almost every important step made by 

 or in this Observatory, Was made known to Pro- 

 fessor Forbes, and almost every scientific entei prise 

 undertaken by him, and his iM-neml proceedings at 

 ihurgh, were soon ronminnieated to me. I forget in 

 ear it was that I testified oflieially to the im- 

 portance of the magnetic determinations wlnYh he 

 bad \\ith so much labour at different elevations 



he sea* 



'The record of his exp< on the conduction of 



lodged, at his ropiest, in this 

 ' 



