ON DISTEIBUTION OP THE RAINFALL. 295 



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

 the debouches of the torrents, has now become critical in the extreme ; 

 and unless we go back, as we have done, to the olden times, we aj-e 

 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 bygone years given their mind to the 

 work, the next generation may hope to see the final decline of the 

 modei'n renewed Torrential Era." 



Views similar to the views thus advanced by Cezanne are advanced 

 by Costa de Bastelica, with this difference that he considers even the 

 mounds of detritus attributed to glaciers have been also the products 

 of torrents, which have become extinct under the effects of the 

 forests. 



In illustration of how the forests may have operated, in those pre- 

 historic times, in arresting the flow of the rainfall, I adduce the 

 following, the type of many others which I have brought forward in 

 the volume referred to. It is from a paper which appeared in Revue 

 des Eaux et Forets, for April 1866. 



" The State possesses, in the department of Vanoluse (says the 

 Forest Conservator, Labuissifere), a forest of more than 3000 hectares, 

 situated on a portion of the mountain Luberon nearest to the valley 

 of the Durance. This region is very much cut up, and traversed in 

 all directions by very narrow and deeply embanked ravines in the 

 midst of masses, more or less dense, of Aleppo pines and green oaks. 



" These ravines are almost the ■ only outlets for the transport of 

 woods, in consequence of the difficulties which woald be encountered 

 and the expense which would be incurred in making more practicable 

 ones on the rapid declivities, strewn with enormous masses- of rook. 

 There exists one so situated, called the Ravine de Saint-Phalez. 

 The direction is from north to south, in the midst of a mass of Aleppo 

 pines in a state of growth more or less compact. 



" Its length, and for four kilometres, or from the road from 

 Cavaillon to Pertuis, to the domain of Saint-Phalez, of an area of 

 about 50 hectares, forms the bassin de reception of the torrent. 



" This land is well cultivated ; there are no declivities too steep for 

 cultivation ; it comprises vineyards, meadows, and arable land ; the 

 soil is argillaceous 



"The ravine of Saint-Phalez receives many affluents, the most 



