468 
Proceedings of the Pioycd Soeiety 
at 81°. The two years of this century in which the mean temper- 
ature was the highest were 1811 and 1822, in both of which years 
it was 49°. 
Of the purely scientific part of the Koyal Society’s work for the 
first fifteen years of its labours, while Hutton and Black and Play- 
fair and Stewart were in full vigour, it is not too much to say it was 
brilliant, full of interest, full of power, and full of enthusiasm. 
The first great Founders, of course, gradually waned, and all such 
associations are necessarily subjected to alternations of the tide; but 
as the tale goes on, the mathematical papers begin to bear the names 
of John Leslie and William Wallace. We encounter Walter Scott 
in 1800, in 1808 the name of David Brewster, and in 1811 that of 
Sir Thomas Makdougall Brisbane, whose names adorned and whose 
labours were in the future the prop and stay of the Society. Of 
Scott I need not speak, but of the services rendered by Brewster it 
is impossible to express myself too strongly. He too, like Playfair, 
had a mind of a rare versatility ; he could observe as well as draw 
from his own resources. He could reason as well as describe. He 
could build a framework of sound deduction from the most unpro- 
mising hypothesis, and work out with unflagging spirit the thread of 
demonstration, however slender. In some respects he differed from 
some of his contemporaries or predecessors. He did not for the most 
part shrink from giving the Society the benefit of his present 
thoughts and current experiments. Sometimes they were imperfect, 
sometimes perhaps even crude, but always full of acuteness, novelty, 
and genius. Had I had the scientific knowledge essential to the 
task, nothing I think could have been more interesting than to have 
traced Sir David Brewster’s first speculations on light and heat con- 
tributed to the Society to the end of his career, and to mark and 
observe how great results gradually crowded on his canvas, to fill in 
the first slight and imperfect sketch. He was the most prolific con- 
tributor of his day ; nor do I think that any one but himself in 
those times could have kept the fire lighted by Hutton and Playfair 
burning so brilliantly. For it is not to be disguised that in the heat 
of the continental struggle an air of languor creeps over the pro- 
ceedings. The joyous enthusiasm of 1783 refuses to be invoked, 
and is solicited in vain. Hor is it wonderful, when the Gauls were 
so nearly at our gates, the safety of our own commonwealth should 
have been comparatively our only care. But when 1815 had arrived. 
