vi.] PROFESSORIAL 7,7/7:'. 127 



tremely well, and promises admirably for the permanency 

 of the Association. 2,700 have been voted for objects 

 of a truly scientific character during next year. . . . 

 My discoveries in heat have been warmly contested in 

 Paris, but, as you are aware, MM. Biot and Melloui 

 have fairly given in. . . .' 



Of Session 1836-37 there remains the following short 

 notice, jotted down by Forbes at a late date : * Had a 

 very pleasant group of students Batten, Cleghorn, 

 J. Anderson, J. Rankine, Harrison the pleasantest I 

 ever had, much occupied with experiments on radiant 

 heat/ Some of the students above named must have 

 been attending his advanced class, or his regular class 

 for the second time. 



The fe\v letters that he wrote during this session were, 

 as usual, almost entirely confined to those scientific sub- 

 jects that were filling his thoughts, either in his lecture- 

 room or in his investigations. 



To M. ARAGO. 



1 January 3d, 1837. 



' I write to mention some results respecting terres- 

 trial magnetism at which I have lately arrived. In 

 1832 1 made an extensive series of experiments with 

 Intensity Apparatus in the Alps, and in 1835 

 in the Pyrenees. One principal object was to ascertain 

 tin- influence of heights. I doubt extremely whether any 

 decided result can be drawn from preceding observations. 

 . . . Those of M. Kuppfer seem to be of little value. 

 They were not made at the summit of the Caucasus. . . . 

 I have referred the positions of my stations in the Alps 

 and Pyrenees to the three co-ordinates of latitude, loiiLii- 

 nd lioiglit, and deduced the influence of each l\ 

 method of .... I ha\v in tin- first install.-.- 

 confined my calculation to h<ni/<>ntal int< -n>ii i< ^. From 

 ditrT.-Mt series of observations, made with two 

 lies, I find always a negative c<>< ilici< nt f the IK i-lii 

 indicating, at a mean, a diminution of oo I of h. 



