STATEMENT BY M, MAllCHAND. 251 



valleys. If the raiu do not supervene the action of the foehn may 

 suffice to cause all the snow to melt aLd to produce great consequent 

 disasters. In 1856 the inundations of the valley of Barcelonette had 

 no other cause of production ; the maximum of the flood was attained 

 under a magnificent sky, and all the water came from the melting of 

 the snow which covered the mountaiu. In Switzerland the terrible 

 inundations of 1868 had in general a double origin — with warm con- 

 tinuous rains were combined the melting of the glaciers. It is always 

 in the spring, or with the first snows of October, that the latter 

 torrents are to be dreaded if the moantaius be not covered with 

 glaciers ; where this is the case the danger is constant, 



" The foehrh sometimes produces geueral raius over the whole of 

 the country over which it blows, but sometimes only local orages, or 

 storms of rain. This can easily be accounted for when it is considered 

 that the contour of the Alps admits of one current of air passing up 

 a valley to be in its cause and in its effects quite independent of a 

 current passing up a neighbouring valley, though they have had a 

 common origin, — and that a difference in the cooling of the currents 

 of air may occasion a precipitation of rain in one valley, while the 

 neighbouring valleys, being warmer, are enjoying a cloudless sky." 



When the late Emperor Napoleon came to power he took steps to 

 give effect to the observations and reasonings of MM. Fabre and 

 Surell, which the pre-occupation of public men with political changes 

 had previously prevented. 



In 1860 the work of reboisement was begun. To the report given 

 by the Director-General of the Administration of Forests, of what had 

 been done in 1867-1868, are appended a number of monographs on 

 works executed in different departments, embracing the departments 

 of the Isere, the High Alps, the Low Alps, Drome, Gard, H^rault, 

 Aude, and the High Pyrenees, all telling of success. 



Amongst others, of which details are given of what had been 

 done, and of what results had followed, is mentioned the case of the 

 torrent of Saint Marthe, on the right bank of the Durance. Of this 

 M. Costa de Bastelica, in a work already cited, remarks : — " This 

 torrent supplies amongst many others a remarkable example of what 

 can be done. In 184:1, when M. Surell wrote his valuable work, this 

 torrent had a sad celebrity for its violence. It swept away every 

 bridge thrown across its course. On every occasion of a storm of 

 rain the inhabitants of the banks of the river were thrown into dis- 

 quietude, fearing to see it burst their dykes, and spread over the plain. 



