MBMOUtE BY DELBEKGTJE-COEMAKT. 77 



continue to sweep on the stones and gravel ; third, to carry the gravel which 

 is dug out from these cuttings to some distance from the edge, to form of 

 them two embankments parallel to the new bed ; fourth, to widen the entry 

 of the new bed at the end towards the mountain, in order to collect the 

 waters, and to strengthen by large stones these widened portions ; fifth, to 

 plant the embankments with wiUows, and other trees which grow quickly ; 

 sixth, to take care to clear away the obstructions which may form them- 

 selves in the new bed after each eruption of the torrent. 



"One may see that there is no need of any building to confine these 

 secondary torrents, and that the inhabitants of each village, with their 

 shovels, their pick-axes, and some wheel-barrows, may secure the territory 

 from the ravages. It is much to be desired, that being enlightened in regard 

 to their true interest, they shoidd lose at last that indififerenoe which keeps 

 them alike from preventing their ruin, and from repairing it. 



" It may be observed that it is not necessary that the new bed be dug 

 throughout aU its length in a single campaign. It suffices to begin at the 

 foot of the mountaiu, and to end off the open part in any year, by a more 

 gentle declivity than that of the deposit of the ravine, to give an outlet to 

 the waters. Thus the inhabitants would do wrong to excuse themselves by 

 an alleged impossibility of doing all the work at one time. Further, 

 neighbouring communities could mutually help one another. 



" The advantages which the commvmes would derive from this work are 

 considerable; for, not only would they not have to fear new invasions of the 

 torrent, but the sides of the torrent, not being now exposed to the waters, 

 might be usefully cultivated, by watering them with waters of the torrent 

 which might be derived from the upper portion of it." 



The scheme proposed resolves itself (he says) simply into digging for the 

 torrent a straight canal through the centre of the deposit, and maintaining 

 this canal by constant clearings. According to M. Ladoucette, whatever may 

 be the precautions proposed by the author for strengthening the hiUs by 

 means of plantations and cuttings like to continuous dykes, they will never 

 present sufficient resistance to erosion ; stiU less will they hold out against the 

 undermining effects of the flood. 



It is mentioned by M. SureU, that the clearing out of torrents is always a 

 difficult operation, on account of the great size of the stones, and the hardness 

 of the mud in which they are imbedded ; and that this work, which demands 

 great waste of muscle, and entails great expense, produces no durable 

 result. The smallest flood suffices to overturn all, and to throw the bed of 

 deposit into its previous disorder. 



Something similar or analogous to the proposal of M. Cormant was carried 

 into execution by M. de Ladoucette, who caused a trench to be cut in a 

 straight line from the gorge of the Durance. He employed in this work the 

 prisoners confined in the central house of Embrun, to the number of five 

 hundred, and the work, prosecuted with energy, was completed in a month ; 

 but in the course of the next month there came a flood, and all was destroyed. 



This scheme attributes all the ravages of torrents to the irregularity of 

 their beds ; and proposes, as a simple and sufficient remedy, to give to them 

 a straight bed. Surell alleges that the scheme confounds cause and effect ; 

 and that torrents do not spread themselves hither and thither because they 

 have not a straight bed ; but they have not a straight bed because, con- 

 tinually depositing matter, they are forced to spread themselves hither 

 and thither. 



