196 



Ivrell carried oh by a conic top, as a flat 

 one; pruning naturally produces the for- 

 mer, while it increases the height ; and, 

 therefore, exposes more surface to the 

 atmosphere, than neglect. — It may be 

 observed too, that provided the leader be 

 kept somewhat clear, we have as yet no 

 rule by which to know what height a tree 

 may attain on a good soil. 



It can be no matter how fast it towers, 

 provided a proper degree of strength be 

 taken alono; with it ; and there can be no 

 danger of that, where the head is never 

 suffered to remain long, either close in 

 itself, or crowded by others. On the 

 whole, we think forty feet distance seems 

 to rest on no better foundation, than an 

 opinion, entertained in consequence of 

 observing the large spreading heads, that 

 are made by trees nearly in a state of 

 nature ; which is generally four times more 

 than necessary ; and therefore, have little 

 doubt but twenty-five feet distance, would 



