198 



in single trees, or hedge-rows. Generally, 

 when a tree is not overtopped by others, 

 has a clear space all round it, and is so 

 stiff a-s not to be nmch affected by the 

 winds, it may be said to be strong enough ; 

 but of that the eye will be the best judge. 



When trees have been neglected, and 

 are grown too weak, by standing close 

 together. Thinning is the only present re- 

 jfuedy, and should be done graduaUi/ ; for, 

 if the plants have long sheltered each other, 

 to remove that shelter all at once, wo-ulcl 

 let in the wind, and otherwise s-tarve them, 

 so as to stint their growth for several years* 



It has always been thought difhcult to 

 explain clearly how trees are affected by 

 sudden exposure, that have previously 

 been sheltered. Undoubtedly, when the 

 wind gets among slender plants, it not 

 only bends and twists their stems, but 

 sprains their roots, so far as in some degree 

 to sprain, break, and disorder the sap- 



