192 OUTLINES OF FORESTRY. 



the rain which falls on such area, instead of 

 slowly draining into the river channel during a 

 comparatively long time, drains rapidly into it 

 and causes disastrous floods. The reservoirs of 

 the springs in such districts thus failing to receive 

 their proper supply of water, are apt to dry up 

 shortly after the beginning of the drought. 



The rapid drainage of the areas from which the 

 forests were removed causes a loss of its surface- 

 soil. 



The soil thus lost to the highlands is deposited 

 in the lower courses of the rivers, in the shape of 

 mud-flats, or sand-bars, which injuriously affect 

 navigation. 



"When soil, rich in vegetable humus, deposited 

 on the lowlands near the mouths of rivers, is ex- 

 posed to the sun's heat, is apt to cause miasmatic 

 or other diseases. 



The ground left bare by the destruction of the 

 forest permits it to both take in and part with its 

 heat rapidly, and thus to permit the air over it 

 to rapidly grow hot in summer and cold in winter. 



Forests should be maintained in some parts of 

 all regions where trees can grow. The best places 

 for such purposes are to be found on the slopes of 

 mountains. 



