INUNDATIONS. 589 



* 



Government to make rules regulating the cultivation of 

 land, the felling or firing of trees, quarrying and pasture 

 on such areas. 



3. Protective Rules. 



Private agency can usually do little or nothing to prevent 

 floods. The action of the State is indispensable, as the cost 

 of the erection and maintenance of the works necessary to 

 secure this object is quite out of proportion to the value of 

 the property on which they must be erected, and the work 

 of fixing the beds of mountain torrents and reafforesting 

 hill-sides in process of denudation must be carried out over 

 a large area. 



The most effective measures depend on the careful manage- 

 ment of mountain forests in the catchment-areas of dangerous 

 watercourses, the main principle being to meet the danger at 

 its source. 



Although observant* people discovered these facts and wrote 

 about them a century ago, a long time elapsed before improved 

 forest management and the erection of the necessary works 

 were undertaken in regions that were threatened in this way. 

 Serious and successful action, however, is now being taken in 

 France, in Austria-Hungary, and in Switzerland, to counteract 

 the causes of floods. 



The chief rules to be followed are : 



i. Regulation of Torrents and their Feeders. The following 

 account of torrents is taken from an address by Fankhauser, 

 to the Berne Forestry Association, June 18th, 1897. 



In every torrent there are three distinctly marked 

 divisions : 



1. The catchment area. 



2. The channel course. 



3. The cone of debris. 



The principal mass of water forming a torrent comes from 

 the catchment area. Single drops of rain falling on the 

 topmost ridges flow down their bare sides in fine, thread- 

 like streams, and unite into larger and larger brooks. Mere 



* Von Aueisberg, Innspruck, 1779. 



