388 



ILLUSTRATIONS OF THE 



L 



X 



rock at the point of Ornex, the neareft part of 

 the granite chain. 



In the prefent ftate of the furface, however, 

 the valley of Orfiere lies between the rocks of 

 Ornex and the valley of the Drance, and would 

 certainly have intercepted the granite blocks in 

 their way from the one of thefe points to the 

 other, if it had exifted at the time when they 

 were paffing over that trad. The valley of Or- 

 fiere, therefore, was not formed, when the tor- 

 rents, or the glaciers tranfported thefe fragments 

 from their native place. 



Mountainous countries, when carefully ex- 

 amined, afford fo many fads fimilar to the pre- 

 ceding, that we Ihould never have done were 

 we to enumerate all the inftances in which they 



They lead to conclufions of great ufe, 

 if we would compare the machinery which na- 

 ture adually employs in the tranfpoitation of 

 rocks, with the largeil fragments of rock which 

 appear to have been removed, at fome former 

 period, from their native place. 



348.' For the moving of large maffes of rock, 

 the moft powerful engines without doubt which 

 nature employs are the glaciers, thofe lakes or 

 rivers of ice which are formed in the higheft 

 valleys of the Alps, and other mountains of the 

 firlt order. Thefe great malfes are in perpetual 



occur. 



motion 



s 



