102 PLANTING. 



only 1152 cubic inches; or if making only one- 

 sixteenth instead of a twelfth, the result is 864 cubic 

 inches, or half a foot. Therefore the tree wOl only 

 contain one-half the quantity of timber at a given age, 

 when making one-sixteenth of layer, that it would if 

 making one-eighth. It must then appear that, unless 

 a tree is allowed conditions under which it can grow 

 sufficiently fast, it will die of disease or old age before 

 it attains proper timber size. 



