of Wells and Springs in Jamaica# 65 
We may, 1 think, from all the obfervations we are yet in 
poffeffion of, conclude, that there is at prefent no fource of 
heat in the earth, capable of affecting the temperature of a 
country, which is not derived from the fun ; and that the 
earth, whatever changes of temperature it may be conjectured 
to have undergone in former periods, is now reduced to a mean 
of the heat produced by the fun in different feafons, and in dif- 
ferent climates. 
Vol. LXXVIII. 
K 
