LADOUCETTE AND DELBEEGUE-COEMANT. 75 



appeared a pamphlet, published in Paris and Toulouse, entitled Mndes sur 

 le Mehoisement des Montagues, par Paul Tray. 



During the years which followed much information was collected through 

 enquiries made by the Government, the substance of which was embodied 

 in documents issued in connection with the legislation which was now 

 employed to give effect to the suggestions which had been made, and the 

 results were to some extent embodied in that legislation; and a good deal more 

 was learned in connection with practical operations which were being carried 

 on, which was embodied in reports of operations and reports of conferences 

 held by appointment of the Administration by the officials and others 

 employed in the work, which were published by the Administration. 



Translations of most of these documents will afterwards be given. But 

 it may be mentioned here that to meet public opinion it was deemed 

 expedient, as the work advanced, to give more attention to gazonnement 

 than was done in the commencement of the operations begun. 



In the citations which have been made from works previously published, 

 one section only of the literature of Forest Science^ — that relating specially, 

 if not exclusively, to the influence of forests on torrents — has been laid 

 under contribution. In regard to that I may say, in a word, that the 

 French literature in this department of Forest Science is saturated with the 

 idea that vegetation is the natural protection of the ground from the 

 consequences of meteorological disturbances, occasioned by the destruction 

 of forests by which a meteorological equilibrium, favourable to agricultural 

 operations, had been established, and which may be re-established by the 

 restoration of sylvan clothing to the mountains ; and the same idea 

 permeates much of the literature of France on subjects allied to that to 

 which I have referred. 



But, while primary importance was attached to rehoisement and to gazonne- 

 ment, mechanical appliances, such as Surell sought to combine, when 

 necessary, with the extension of vegetation as a means of bridling, and 

 stifling, and controlling torrents, did not fail to command the attention of 

 those who were interested in the struggle, which was the more necessary 

 that there are destructive torrents produced by the melting of snow, and 

 the rapid melting of glaciers, or by debdcles, the breaking up of icy barriers 

 confining waters, in situations in which rehoisement and gazonnement are 

 impracticable, and therefore as a remedy inapplicable ; and there are other 

 torrents of which the same thing, or something similar, may be alleged in 

 regard to these appliances. 



There is given by M. de Ladoucette an exposition of a scheme of embank- 

 ment proposed by M. Delbergue-Cormant, Inghiieur en cMf des Fonts et 

 Chaussies. The following is a translation of the memoir by M. Delbergue- 

 Cormant, cited by him : — " There are two kinds of torrents, principal and 

 secondary. The first are easily distinguished, — they always flow in the 

 principal valleys ; thus the Durance, the GuU, the Deux-Briich, the 

 Drac, (fee, are principal torrents. 



"The second descend from the lateral mountains of the valley, and come 

 often at an angle more or less approaching 90°, to increase the principal 

 torrent, which occupies the depth of the valley ; it follows from this that 

 the torrents of Sarrazin, of Boscodon, are secondary torrents. The means 

 employed hitherto to control the principal torrents are to enclose them by 



