THINNING. 77 



known to all practically connected with timber, that 

 a conical-shaped tree is by no means the most desir- 

 able or best, but, on the contrary, that a cylindrical- 

 shaped tree is the best form. But if in the young 

 state the tree is conical, how can it be transformed 

 into a cylindrical-shaped one in after years? Thinning 

 can do it, in the followincf manner. 



The annual layers, zones, or rings of wood upon a 

 tree are just thick or thin in proportion to the number 

 of branches upon the stem. If the branches are few 

 in number and small in size, the layers will be thin ; 

 whereas if they are numerous and strong, the layers 

 are thick. That part of the tree, too, immediately 

 below the junction of the branch with the trunk, is 

 enlarged by the sap elaborated in that branch, and in 

 proportion as the branch is large or small, healthy or 

 sickly, will the thickness of the layer be influenced. 

 If a tree be forty feet high at the time when 

 thinnincf is beincj discontinued and considered as no 

 longer beneficial to the crop, and the tree clothed with 

 branches from top to near the base, it will girth 3 feet 

 4 inches at or near the ground, being nearly an exact 

 cone both in stem and outline of branches. Theory 

 teaches this, and observation in the writer's experience 

 confirms it. How to reduce a cone then to a cylinder 

 is the problem for the forester to solve, and is done 

 thus : Layer at base Aths of an inch, at top joths — 

 gain, 3 J- inches diameter in forty years. As every top 

 growth or shoot corresponds to one ring in the stem 

 below, and every tier of branches belonging to the top 



