158 



THINNING. 



(if there are sufficient trees upon the ground) be 

 reduced. 



Having found out, by careful study and observation, 

 that a well-proportioned and properly -balanced tree 

 measures as many feet in height as it girths inches, 

 I was further anxious to know what proportional 

 weight the branches of such trees bore to the stem on 

 which they grew ; and in order to ascertain this, I cut 

 down, in the process of thinning, some specimen trees 

 of the following species, and after carefully weighing 

 them, I found the following results : — 



The height and girth in the above table are not 

 exactly proportional, as it is very difficult in making 

 a selection to find them so, but the approximation is 

 sufficiently near for the purpose of showing the require- 

 ments of practical forestry according to our definition 

 of it. The form or outline of the tree, up to that 

 period when thinning should be discontinued, should 

 be conical or tapering, both in the stem and general 

 form of the tree. After thinning is discontinued the 

 shape of the tree alters, both in the stem and branches ; 

 the latter wither and. fall off till only the top is covered, 

 and the former gradually changes from a cone to a 



