392 THE LIFE OF JAMES D. FORBES. [CHAP. 



with merely apprehending a truth, but he viewed it in 

 all possible lights, and finally selected some one as the 

 best point of view from which to faint it to his class. 

 There was thus engendered in the minds of his pupils, 

 not only the effect directly due to such a description, but 

 the indirect feeling that their teacher had taken great 

 pains and care to produce this result. Perhaps you are 

 aware that I acted as his assistant during the sessions 

 1856-7, 1857-8, 1858-9, during which time it was my 

 duty to lecture on mechanics and the more mathe- 

 matical part of his course, while he lectured on the 

 subjects which are generally embraced in treatises on 

 physics. 



' 1 had the benefit of very full notes of his lectures, 

 and I often think that it would be to the advantage of 

 science if his lectures could be published. 



4 1 learned, during the time that I assisted him, several 

 points regarding him that I had not previously known. 

 He was among other things very clear in his pronuncia- 

 tion, and he told me that in order to obtain it he had 

 taken lessons from Mrs. Siddons. During the time I 

 used to assist him in his experiments, I learned to notice 

 the caution combined with sagacity, the union of the 

 centripetal and centrifugal principles, that was an emi- 

 nent characteristic of his mind. He was not satisfied 

 in his own researches with viewing a thing in one light, 

 but he insisted on verifying his conclusions by corrobo- 

 rative evidence derived by regarding the subject from 

 another light. 



* I ought not to forget his great kindness to me in 

 some experiments on radiation which I made when I 

 was his assistant, and for which I have since received 

 the Rumford medal of the Royal Society, London. He 

 very generously gave me many hints, and allowed me 

 to use not only his own apparatus, but to make use of 

 his valuable specimens of rock-salt. Had it not been 

 for these facilities, I should not have succeeded in the 

 investigation to any extent. 



* These are my chief remembrances of Principal Forbes. 



