THEORY OF THE EARTH. 17 



peaks rise above all these shelly strata, that their 

 summits had already emerged from the waters, 

 when the shelly strata were forming. 



Such are those celebrated Primitive Mountains 

 which traverse our continents in different direc- 

 tions, raising themselves above the clouds, sepa- 

 rating the basins of rivers from one another, af- 

 fording, in their perennial snows, reservoirs which 

 feed the springs, and forming, in some measure, the 

 skeleton, and as it were the rough framework, of 

 the Earth. 



The eye perceives from afar, in the indenta- 

 tions with which their ridge has been marked, 

 and in the sharp peaks with which it is bristled, 

 indications of the violent manner in which they 

 have been elevated. Their appearance, in this re- 

 spect, is very different from that of those rounded 

 mountains, and hills with long flat surfaces, whose 

 less ancient masses have always remained in the 

 situation in which they were quietly deposited by 

 the waters of more recent seas. 



These indications become more obvious as we 

 approach. The valleys have no longer those 

 gently-sloping sides, those salient and re-entering 

 angles corresponding on either side to each other, 

 which seem to denote the beds of ancient streams. 

 They widen and they contract without any ge- 

 neral rule ; their waters, at one time, expand in- 

 to lakes ; at another, fall in torrents ; and some- 



B 



