THINNING. 



175 



actually taken place that its application is generally 

 thought of. 



In order that thinning may be really serviceable, 

 it must be applied early. To specify any particular 

 period would be useless, as this must depend on the 

 quick or slow^progress the plants have made since 

 they were placed in the situation which they occu- 

 py. The best rule, and one, perhaps, that may be 

 regarded as entirely unexceptionable, is to commence 

 the process as soon as the branches of different trees 

 begin to run foul of, and interfere with, one another. 

 So long as a tree stands completely clear of those in 

 its vicinity, the air can circulate about every part of 

 it ; and this is amply sufficient for all the purposes 

 of vegetation. To cut down any of its neighbours 

 while it remains in this state, would be to deprive 

 it of the requisite shelter, and to hurt it by prema- 

 ture exposure. 



Let it not be inferred, however, from what is here 

 said, that it would be proper to delay the operation 

 till the branches of all the trees of a plantation ran 

 foul of each other. Before this took place^ immense 

 damage would be already committed, and things 

 would, in fact, be in a condition that could receive 

 no benefit from the process in question. If there 

 should not be more than twenty trees among twen- 



