56 LITEBATUEE ON TOERKNTS. 



" 146. The first disaster produced hy the two causes of which we have just 

 tpoken is the ruin of our forests. 



" If there had existed wise laws, and these had been carefully executed, 

 we should have had now building timber in such quantity as to permit of 

 exportation. We should also have had in abundance wood for carpentry 

 and fire-wood. It is felt that both of these things are essentially necessary 

 in a well organized state. But they fail us to such a degree that in a great 

 number of communes there is not even fire-wood. The evil has been long 

 felt, and the necessity of remedying this is urgent. 



" 147. The second disaster is the destruction in a great many places of the 

 led of vegetable soil with which our mountains were covered. 



" This bed would otherwise have produced abundant pasturage for the 

 sheep, but, can-ied away by the storms and torrents, there remains at 

 present on these mountains only a naked and dry rock. From this results 

 necessarily a diminution of the small number of cattle which France might 

 have been able to support if these pasturages had continued to exist. 



" 148. The third disaster is the ruin of the domains which lie upon 

 the 7'ivers. 



" We have seen that the swellings of the torrents were stronger in 

 proportion as the mountains were less wooded and more impoverished. 

 These swellings are then gTeater now, through the operation of the two 

 causes mentioned above, than otherwise they would have been. They 

 ought, therefore, to cause, and they do really cause, much more havoc to 

 the domains along their course than they othei'wise would have caused. 



" On the other hand, we have seen that it might happen, as it has in 

 effect happened too often, that the torrents in issuing from their bed or 

 channel would cover adjacent domains situated at the foot of the mountains 

 with deposits, which absolutely alters their nature. Now, this never 

 happened until that by the operation of the two causes mentioned above 

 the torrents were formed. 



" 149. The fourth disaster is the drainage, experienced in tlie navigation of 

 the rivet's, by the divisions in the water-courses, which are the consequents of 

 great floods. 



" 150. The fifth disaster cotisists in the strifes and contentions, between the 

 proprietors on opposite hanks of the river, to which the divisions in these water- 

 courses give rise. 



" 151. The sixth disaster results from tlie deposits which tliey make at tJte 

 mouths of the streams, luhich often inte!-cej:>t the navigation." 



Each of these three statements is illustrated in detail. 



" 152. In fine, the seventh disaster consists in the diminution of the sources 

 which feed the streams and the rivers in their ordinary state. 



" We have seen that springs, the sources of streams, are formed from the 

 rains which filtrate through the earth and meet in the subterranean reser- 

 voirs, whence they escape by minute channels, and make their appearance 

 at the surface of the ground. Now, if the mountains be despoiled of their 

 bed of vegetable earth, and there remain only the bare rock, it is evident 

 that the water of the rains will no longer filtrate through the soil, but wiU 

 flow quite superficially ; thence it follows, that as the fountains diminish so 

 must the rivers which they feed ; and a time will come when even the 

 rivers which at present are navigable will cease to be so. True, indeed, that 

 time is still distant, but sooner or later it will arrive if the cause which 

 produces this efiect be not destroyed." 



