242 ACTION OP FOEESTS ON THE FLOW OP RIVERS. 



natural extinction of torrents, he, in something like a burst of en- 

 thusiasm, gives expression to his feelings in view of the thorough 

 and efficient way in which torrents had naturally become extinct, and 

 of the contrast thus presented to the puny endeavours of man to 

 restrain their ravages : the natural and the artificial ; God's way of 

 doing it, and man's way of doing ; the work of God and the work of 

 man ; and the results : success, perfect and complete ; and success, 

 partial and imperfect ! 



" Let VIS go back for a moment," says he, " and compare these 

 effects of vegetation with those exercised by the different systems of 

 defence hitherto devised. The result of defences like that of vegetation 

 is to arrest the ravages of torrents ; and how powerless appear all 

 embankments by the side of those great and powerful means which 

 natui'e employs when man ceases to oppose her, and when she patiently 

 prosecutes her work throughout a long series of ages ! All our paltry 

 works are nothing but defences, as their name indicates ; they do not 

 diminish the destructive action of the waters, they only keep it from 

 spreading beyond a certain boundary. They are passive masses 

 opposed to active forces ; obstacles, inert and decaying, opposed to 

 living powers, which always attack, and which never decay. Herein 

 is seen all the superiority of nature, and the nothingness of the artifices 

 devised by man. 



" I make not here a barren comparison. I wish to let it be seen 

 that it is better to bridle the torrents than to erect at great expense 

 masonries and earth-works, which will always be, whatever may be 

 done, expensive palliatives, better adapted to conceal the plague than 

 to eradicate it. Why then does not man ask assistance of those new 

 powers, the energy and efficacy of which are so clearly revealed to 

 him ? Wliy does he not command them to do yet again, and that 

 under the directions of his own genius, that which they have already 

 done in times long gone by on so many extinct torrents, and that 

 under the prompting of nature alone V 



In 1872 a sequel to this work by M. Surell was published by M. 

 Cezanne, Ingeneiir des Fonts et Chausees, Representant des Hautes 

 Alpes a r Assemble Nationcde. Referring to the phenomena of torrents 

 brought under review in that work by M. Surell, and in the Sequel 

 supplied by himself, M. Cezanne says : — 



" There may be given in a few words a resxmie of the whole series 

 of these phenomena. 



" The mountains are the result of a series of upheavals following 



