344 ACTION OF F0PEST8 ON THB FIjOW_OF BIVBBS. 



the primary inhabitants could profit by the exceptional fertility of 

 the cone of deposits ; they had nothing to fear from the principal 

 river, which flowed through the lower-lying lands, nor from jthe 

 torrent, which was then extinct ; they commanded the plain, and 

 found themselves at the gate of the mountains ; the adjacent gorge 

 supplied them with water, the forest supplied them with wood, the 

 rock supplied them with stone, and their flocks spread themselves 

 over the verdant ridges around them. 



" Little by little, a reckless use of the forests and of the pasturage 

 disturbed the equilibrium of the natural forces ; and now the old sore 

 is re-opened, and anew, by man's deed, the mountains are inoculated 

 with the leprosy of the torrents. The evil has gone on increasing 

 during prolonged ages of disorder and recklessness ; the position of 

 the cultivated grounds, and of the villages established at the debouche 

 of the torrents^ has now become critical in the extreme ; and unless 

 we go back, as we have done ; to the olden times, we are unable to 

 account for men having taken up their dwelling in the spots, of all 

 others, which at this day appear to be those which are more 

 immediately threatened. 



" But at last an era of reparation begins ; and, thanks to the eminent 

 men who have in byegone years given their mind to the work, the 

 next generation may hope to see the final decline of the modern re- 

 newed Torrential Era." 



In 1874 was published Les Torrents leur lois, leur causes, leur (fets: 

 Moyens de les reprimeur et de les utiliser : leur action geologique 

 universelle, par Michel Costa de Bastelica, Oonservateur des Eaux et 

 Forets. 



This work treats of another aspect or of another department of the 

 subject than any discussed in the treatises already mentioned, which 

 the author designates, — Le phemmene torrentid, or la torrentialite ; 

 and thus is opened up another chapter of the natural history of 

 torrents. 



In speaking of the good done by forests on the face of moun- 

 tains forming a basin drained by water-courses, he says their bene- 

 ficial action is manifold; and though this manifold action it may 

 be difiScult to unfold, the attempt to do this will place beyond all 

 question that their beneficial action on the water-course is at once 

 most marked and considerable. 



" In the discussions which have taken place on this subject," saya 

 he, "the point which has engrossed attention to some extent has 



