160 FOREST PLANTING. 



Drainage and burning oyer the surface soil being the 

 principal means to bring the moors into such a condition 

 as to plant forest-trees upon them, are, therefore, so 

 important that they may well form the subject of a 

 special consideration. 



CHAPTBK V. 



DRAINAGE. 



When moors are to be prepared for tree-growth, the 

 first step to accomplish this end is to apply drainage. 

 By this it is not intended to remove all of the humidity 

 out of the ground, but only the excess of water — a 

 water-soaked soil being detrimental to every plant- 

 growth. 



In bottom-lands, drainage is often dammed up by the 

 high water-table of adjoining rivers, but the hilly up- 

 lands afford ample opportunity for the application of 

 this improvement. 



In order to render the drainage of a place or district 

 perfect, a careful investigation of the entire locality 

 should be instituted, and its topography, including the 

 courses of the streams and rivers, should be minutely 

 mapped out. Thereupon the elevations of the surface 

 and the height of the water-table should be found out 

 and marked on the map or chart. 



After the level of the place, both in regard to its prin- 

 cipal part and the adjuncts, has been ascertained, a 

 system of drains and their operation, by which the 

 excess of water may be let off, can be easily delineated. 

 First, an appropriate direction has to be given to the 

 main or receiving ditch. Commonly, this direction will 



