2 Reafons for fuppofing that 
this grand revolution has been produced by fubter- 
raneous convulfions. Why, then, are Lakes fo 
few in number?—is a queftion which, at the firft 
view, prefents itfelf to the mind. Lakes are either 
depreffions or chafms in the ground, where the 
waters of the neighbouring country are collected. 
And, if whole continents have been torn up, 
and have had their continuity every where broken, 
why are not cavities proper for forming fuch 
refervoirs more frequent ? 
This view of the fubje& certainly offers a formi- 
dable objection to the received theory of the 
formation of land, which ought to be attended to. 
I will therefore make it the bufinefs of the prefent 
eflay to enquire, whether it can be fairly obviated 
by an attention to the refources of Nature, and to 
that gradual progrefs from a rude to a more perfect 
{tate, which the obferves in all her works. 
We know that the face of the earth is not now 
what it was formerly. Mountains, whofe acclivities 
are at prefent eafy and gentle, were once inaccef- 
fible through rocks and precipices. Large diftricts 
of land, which, at one period of time, wete 
obftructed with fragments of ftones, and buried in 
athes, -have been gradually fertilized by the remains 
of decayed vegetables, and the decompofition of 
volcanic fubftances. Some rivers have deferted their 
ancient channels, whilft others have been entirely 
loft. All thefe great changes have been effected 
without violence, by the action of flight but 
inceffant 
