ON THE ACTION OF RUNNING WATERS. 437 



the universal deluge, namely, that which maintains that 

 it is proved by an appeal to the phenomena of the mine- 

 ral kingdom ; the other, which affirms that that great 

 event has left no traces of its existence on the surface 

 or in the interior of the earth. M. Cuvier's Essay, and 

 Professor Buckland's Reliquiae, are the best authorities 

 for the first opinion ; while numerous writers have advo- 

 cated the second, 



NOTE, p. 244. 



,ON THE ACTION OF RUNNING WATERS 



A very great degree of power has been attributed to 

 the waters which move at the surface of the earth, or in 

 its interior. Many geologists have advanced the opinion, 

 that they have scooped out the channels and even the 

 valleys in which they flow, and formed the cliffs whose 

 feet they wash ; and many philosophers, naturalists and 

 even geologists, still support this opinion, not only in 

 some of its applications, but even in its whole extent. 



In order to appreciate it, it is sufficient to observe with 

 care the different modes of action of water set in motion 

 by different causes, and the changes which it has operat- 

 ed upon the rocks and deposits upon which it has acted, 

 from the most remote times to which history may reach. 



We must, in the first place, successively examine the 

 different sorts of action of the principal masses of water 

 which are in motion at the surface of the earth, that is to 

 say, the action of torrents, of rivers, of currents of the 

 sea, or of great lakes, and that of waves. 



We shall afterwards see what consequences are to be 

 deduced from these observations. 



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