138 ON PRUNING FOREST TREES, ETC. 
in proportion to their height. A good proportion in a tree of 
thirty feet in height is twenty feet of top to ten feet of bare 
trunk; but no given rule in this respect can be exacted for 
all sorts, as a longer top is requisite in a rough exposure and 
in poor soil than where the ground is well sheltered and 
fertile. The skilful forester observes at a glance whether 
the tree is possessed of a trunk stout in proportion to its 
height, and, as in thinning, regulates the pruning accordingly. 
Where height is required he subdues the side branches ; where 
girth of trunk is necessary, he preserves them as the speedy 
means of obtaining girth. 
The evil consequences of cutting off large side branches 
from timber trees require to be stated, as nothing can more 
readily deteriorate their value, particularly if the branches are 
cut close to the trunk. This creates a large unsightly wound 
several inches in diameter; the influence of the sun and 
weather cracks the timber, which imbibes water ; during frost 
the fissures increase, and rottenness penetrates into the trunk, 
and although the wound will collapse, and repeated layers of 
wood in course of time will cover it over, yet the timber 
remains unsound and much deteriorated. The experienced 
timber-merchant has a quick perception of the marks of 
lopping or mutilation, which often reduces the value of timber 
one half, and where indications of the removal of large 
branches appear, the forester is sometimes obliged to defer 
fixing the price till the wood has been cut up. It is mutila- 
tion of this sort that has created a prejudice against any 
description: of pruning whatever, particularly with wood- 
merchants and artisans. Where it is absolutely necessary to 
remove a large branch, the method most safe for the timber 
is to amputate it beyond its first side branches, which will 
generally prevent dead or unsound timber. 
As to the season most suitable for pruning timber I may 
state that the shortening of stronger side branches and of the 
competing shoots near the leader may be performed at any 
season ; the outline, and consequently the wants of the tree, 
are best seen during winter or early in spring, in the absence 
