ae Reafons for fuppofing that 
has, in fome places, demolifhed the hardeft ftrata 
to a depth fcarcely to be credited. Now it is 
evident, that, where the fame caufes have been 
applied to the bank of a lake, they could ‘not fail 
of producing the like effects as when exerted on 
the fide of a hill. It may, therefore, be taken for 
granted, that the outlet of every lake has been 
more or le’s injured in the manner defcribed above. ' 
This conclufion. being admitted, the following 
confequences muft immediately be affented to; 
becaufe they depend on the fimpleft laws of rice 
ftatics. © 
Firft: Wherever this procefs has taken place, 
the dimenfions of the water contained in the refer- 
voir always diminifhed as the depth of the channel 
increafed through which the fuperfluous part was 
difcharged. . 
Secondly: Its banks were gradually enlarged; 
and the inequalities of the bafon began to rife 
above the furface, and affumed the appearance of 
iflands. 
- Laftly: Wherever the fituation of the difcharg- 
ing river would permit its bed to be worn to the 
level of the loweft part of the refervoir, the Lake 
has difappeared; and we find, at prefent, a valley 
in its room, containing very ftrong proofs of its 
own formation in the ffratum of fand and pebbles 
with which its fides are covered. The particular 
fituation of the outlet here alluded to depends on 
the figure of the bank where it is placed, which 
muft 
