144 rRELnriNARY works. 



followed by <];raclual deniulation, or landslips. In water 

 channels the banks may be undermined. The result is a 

 reduction in the productive power of the slopes, while the 

 level ground l)elow may be covered with the del)ris brought 

 from 'above ; at any rate the water channels in the low land 

 silt up, and give rise to inundations. 



The detailed consideration of this subject belongs to Forest 

 Protection.* It will suffice here to state that the best pre- 

 ventive measure consists in keeping such ground permanently 

 under forest growth, from which domestic animals sliould be 

 excluded. 



If a bare area exposed to denudation is to be stocked, it 

 may be necessary to fix the soil before sowing or planting is 

 attempted. This is done by regulating the existing water 

 courses, terracing them, and even erecting wooden or masonry 

 revetments. Where necessar}-, additional water channels 

 must be cut to lead off all surplus water into the regular 

 channels. Cattle of all kinds must be strictly excluded. 

 The land itself may have to be terraced, or wattle fences may 

 be erected at suitable intervals. Only after the soil has been 

 rendered stable can the formation of a wood be commenced. 



Works of the above mentioned kinds have been executed on 

 a large scale in the French, I Swiss and Austrian Alps, 

 as well as in the Jura. 



* For further details see Volume IV. of lliis Manual. 



t See " Traite pratique du Reboisenient et du Gazonnement des Montagnc.*," 

 by P. Demontzey. Paris : Rothschild, 13, Hue des Saints-Peres. 



