r 



-4^ 



Yt 



tier 



^ 



k\ 



HUTTONIAN THEORY. 



e 



"iVpft: 



e 





fee 



H 







s 



I 



re 



•f 



lakes, and change the relative level of their 



Tides and bottom. 



328. All lakes, however, do not involve the 



difficulty which the preceding conjedures are in- 

 tended to remove. The great lakes of North 

 America do not, for inftance, receive their fup- 

 ply from very large rivers. Of courfe, it is not 



from a trad: great in comparifon of themfeives, 

 that the vvafte and detritus is brought down 

 into them ; and it feems not at ail wonderful, 

 that, without being filled up, they have been 

 able to receive it. The fame, in a degree at 

 leaft, is true of many other lakes. 



It lliould alfo be coniidered, that we may 

 err greatly in the eilimate wd make of the ma- 

 ^ that kllff terials adually carried down and depolited in 



^« of lakes; 



!{[ 



•e but lii 



indeed tie ( 



^M fcri 

 •ailed op fa' 



! 



ii and flaf, I any lake. To judge of their entire amount, we 



fliould know the original form of the inequali- 

 ties on the earth's furface ; of the quantity of de- 

 preffion which exifted, independently of the ri- 

 vers ; and though, in general, thefe original ine- 

 qualities may be overlooked, and the prefent 

 confidered as made by the running of water, 

 yet, in particular inflances, this may be far from 



wanting, is 



not uniform; i* 



the ii^' 



• in 



« 



bicli t 



i 



of rre3t fit' 





•>, 



f 



true. The Vallais, for example, which we con- 

 fider as the work of the Rhone, may, when the 

 Alps rofe out of the fea, have included many 

 depreffions of the furface, which the river join- 

 ed together, and, from being a feries of lakes, 

 formed into one great valley. 



329, The 



i 



