92 MODERN FOREST ECONOMY. 



which can be named which the erosion of torrents have 

 made so unstable that it has become impossible to build 

 upon them. On the left bank of the torrent Les Moulettes 

 there may be seen houses belonging to the village of Les 

 Andrieux, which have be, en rent at a distance of more than 

 800 metres from the bed. On the highway, No. 91, oppo- 

 site Les Ardoisieres, we have an example of a considerable 

 revers of a mountain eaten away by the Romanche and 

 disturbed by continual movements of the soil. The 

 instability of the soil has compelled many families to 

 abandon cottages situated at a great distance from the 

 river. One could scarcely comprehend that that could be 

 the cause of movements so remote, if the analogy of facts 

 and other evidences had not proved it to be so in a 

 manner the most irresistible.' 



Numerous cases are referred to in a note followed up 

 with the remark, 'I have thought it right to multiply 

 citations, because the cause of these movements has been 

 often misapprehended, and notably so in the case last 

 mentioned. The inhabitants attribute it to some particu- 

 lar character of the ground. Having under their eyes only 

 the case of their own locality, they are not aware that it is 

 a phenomenon quite general and common to all torrents.' 



He specifies movements of the soil in the mountain of 

 Saint Sauveur, over against Embrun, brought about by the 

 torrent of Vacheres, and by a great many other torrents of 

 the third class ; also similar movements in the district of 

 Vabries, mined by the torrent Crevoux on the left bank, 

 and in the district of Villard Saint Andre, by the same 

 torrent on its right bank ; it is stated that this ground had 

 become more mobile subsequently to the formation of a 

 canal for irrigation ; accounts are given of similar move- 

 ments attributable to the torrent of Sainte-Marthe, near 

 Caleyeres, in connection with which it is stated that there 

 was there a mill apparently on the point of being engulfed, 

 and of movements, attributable to the torrent Merdanel, 

 above Chadenas ; and it is stated that very violent move- 

 ments have been observed in the districts of the Diveset, 



