58 On the biipey of ia igi ‘and Sout 
bits w, 10 3 brewed 
Vv. On. the gradual Changes in “Temperature and Soil With 
| take. place in different, Climates, with an Enquiry into the 
_, Caufe of thofe Changes. By the Abbe MANN. 
ai » [Gqngluded from Page 347 of the lait Volume. a 
II. Py Caufes of the gradual Alterations i in Soil’ and the 
Ree emporiature of ibe. Climate, pai: 
tre 4 
tee 
at HAVE no doubt that’ a great diester of different: Abie 
may ‘have contributed, ‘each its patt, more or lefs, to pro- 
duce thofe HEAR Hy Hiee are the object of the prefent re- 
fearch. Some Of thein are only accidental, and have taken 
place i in different countries at very &revent’ periods, while 
in others fome of them have not taken place at all. Among 
thefe are the draining of lakes and morafles, the extirpating 
of forefts, and the calli vation of land, All thefe cireum= 
flances, no doubt, ‘rendér the tempera: tire of climate milder. 
I found, however, one’ caufe, of a kind altogether different, 
which appears to me general and uniform in producing the 
above changes. “After what I have before faid, and in an- 
other place , it may be readily conjectured that I here fpeak 
of an union of the two diftiné principles, moifture and 
heat. Their niutual difengagement, and the increafe of the 
one above the other, afford, if I am not miftaken, a key t 
a true theory of the earth, 
~All the ancient writers who fpeak of the countries of Eu- 
rope beyond the latitude of 50° north, reprefent them as 
filled with Jakes and moraffes, and covered with immente 
forefts, almoft as America I$ at prefent. It is a certain fact, 
that the climate of North America is different from that of 
Europe by about ten degrees of pee eet ; oy the dif- 
trifts of North America lymg under 40° of nofth latitude 
are as cold and moift as the countries of Europe which lie 
in the latitude of 50°. New England lies between the 41ft 
and 46th deerees of latitude; yet it is obferved that the cli- 
mate there, in regard to heat and cold, is equal to that of 
* Sce my Muynoir on the Ancient State of Flanders in Memoires dé 
V Acad. de Bruxelies, Vol, 1. p. 6772 
the 
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