DROWNING THE TORRENT IN VEGETATION. 71 



sheep brought into the impoverished communal treasuries seemed in- 

 dispensable, though it was easy to see that it was bad economy to ad- 

 mit them. Such trampling and tearing weakened the turf so that it 

 was every year more easily washed down-hill during heavy rain, and, 

 when it went, the soil underneath went too. The farther down the 

 mud and water rushed, the deeper and wider were the erosions. Upon 

 the steeper slopes below, which should have been clothed with woods, 

 the ravages were still greater. As like causes were operating in a 

 similar way upon other surfaces in the same basin, after every heavy 

 rain (especially if it fell upon deep snow) the streams suddenly rose 

 thirty, forty, and even sixty feet, and then again, in a few hours, were 

 at their old level. 



If a bank overhanging the narrow gorge at the mouth of one of 

 these mountain-basins was undermined and fell across the opening, a 

 lake quickly formed behind, until the accumulating pressure burst the 

 barrier, and then woe to the people down-stream ! In one such de- 

 hdcle the wave was one hundred feet high, and swept down the valley 

 at the rate of fifty feet a second, or thirty-four and one eleventh miles 

 an hour ! " At one point the water was seen pushing before it a mov- 

 ing mountain of all kinds of debris of three hundred feet in height, 

 from which was rising a thick cloud like the smoke of a conflagra- 

 tion " (Brown's " Reboisement in France," pp. 86-89). 



Deprived by their own improvidence, or that of their parents, of 

 their forest wealth, the mountaineers thought that they must starve, 

 or else use every available acre for pasturage. Planting trees and 

 waiting for them to grow required knowledge and capital, and they 

 had little of either. The damage done by torrents was more severe 

 farther down, although it all began in the uplands, whose turf was 

 loosened by the starved sheep of the south. Lack of the timber 

 which should have enriched and protected the zones just below these 

 pastures made the mountaineers feel so poor that they felt constrained 

 to take every sheep and goat which the lowlanders would bring. 

 It was clear that they could not restrict the number of these " summer 

 boarders " and at the same time reforest the steeper lower zones to the 

 extent which was demanded by their own welfare, and still more by 

 that of the people living farther down-stream. 



This made it necessary for the state to step in. Under the feudal 

 system it was held that a seignior, and especially a king, must possess 

 one or more forests. In France, those belonging to the crown have 

 become the property of the state, and, for the care of these there have 

 gradually been trained a special class of officers. When the reboise- 

 ment law of 1860 was passed, many of these were men of great attain- 

 inents. Surell, born in the Departement des Hautes-Alpes, was one of 

 the most eminent among them. As an engineer he had long been fa- 

 miliar with the numerous and costly — and yet inadequate — mechanical 

 expedients which had been tried by the authorities for the purpose of 



