214 
SECOND REPORT- 1832. 
factory character than perhaps any other branch of Meteoro¬ 
logy. That work has been too long in the hands of every one 
interested in the particular subject, or in the skilful generali¬ 
zation of groups of facts, to require any notice here ; and in 
touching upon what has been more recently added to our 
knowledge of the subject, we must confine ourselves within 
the narrowest limits. 
The opinion that the climate of a particular place, or of the 
globe generally, has materially changed during historic records 
is improbable ; and all the force of that precise and circumstan¬ 
tial evidence which ought to carry weight with it, is against 
the idea. The eminent naturalist M. Schouw, who has recently 
published upon several points of interest connected with Meteo¬ 
rology*, has written an Essay, replete with curious matter, upon 
the supposed change of climate since ancient times, part of 
which has been translated into English , which goes to show 
that we have no authority for assuming such a change. A 
similar result has been arrived at by M. Arago, who has collected 
a number of curious facts relative to great colds which have oc¬ 
curred at Paris, showing, in opposition to an opinion which had 
been started, that we have no reason to believe the climate to 
have been deteriorating for some centuries past J. We have 
already quoted the results obtained by Sig. Libri from the 
registers of Raineri at Florence. 
The old formula of Mayer for expressing the mean tempera¬ 
ture of any place in terms of its latitude, which made the tem¬ 
perature of the equator 85°, and of the pole 32°, though a 
respectable generalization for the time at which it was made, 
was not calculated to stand the experience of another century. 
Captain Scoresby, I believe, first pointed out its great inaccu¬ 
racy ; and Dr. Brewster, in a paper presented to the Royal 
Society of Edinburgh and printed in their Transactions 
showed that the deductions of Humboldt in his Essay on Iso¬ 
thermal Lines would be far better represented by the simple 
formula 
t = 81°’5 cos L, 
t being the mean temperature of a place in latitude L. This 
* Particularly connected with the geography of plants. See an Essay on 
the Geographical Distribution of the Vine, Edin. Phil. Journal ; and an interest¬ 
ing brochure , entitled Specimen Geographies Physicce Comparatives, Hauniae 
1828, which contains some interesting comparative views of the climate of the 
Alps, Pyrenees, and Scandinavian range, the position of the snow line, &c. 
We have already quoted his work on Comparative Climatology. 
b Edinburgh Journal of Science, viii. 311. 
J Annuaire du Bureau des Longitudes, 1825, § vol. ix. p. 201, 
