HUTTONIAN THEORY. 



pr 



•i 



k 



\ 



I? 



td 



that this theory accounts, with lingular fimpli- 

 city and precifion, for a fyflem of fads fo va- 

 rious and complex, as that which is prefented 

 by the natural hiftory of the globe. 



86. Neither can it be faid that the exiftence 

 of fubterraneous. heat is a principle 



aifumed 



any evidence, but that of the geolog 



fad 



It IS 



ded to 



pi 



on th 



iry, it is proved by phenomena within the 

 of ordinary experience, namely, thofe of 



hot-fprings 



u 



d earthquakes. Thefe 



leave no doubt of the exiftence of heat, and of 



moving and expanli 



po 



the 



rth 



fo that the 



in the bowels of 

 queilions are, at 



t 



hat depth is this power lodged 



? 



hat 



and with what intenfity, does it ad 

 lodged at a very conliderable depth 



Th 



/ 



dered probable by the permanency of fome of 



the preced 



phenom 



from th 



ft 



y fountains have retained their h 



the prefent day ; and volcanoes, though they be 

 come extinguiflied at length, have a very Ions 



period allotted for their d 



The caufe of 



earthquakes is certainly a force that refides very 

 deep under the furface, otherwife the extent of 



' r 



the concuffion could not be fuch as has been ob^ 

 ferved in many inftances. 



Th 



ntenlity of volcanic fi 



mftance that favours the opinion of 



> 



be^ 



