FIR PLANTATIONS. 143 



timber at the end of sixty years, than one of the 

 same extent thinned at intervals of ten years. 



Every fir plantation, whether that may be com- 

 posed of larch, Scots, or spruce, ought to be gradu- 

 ally thinned as the trees advance in height and 

 breadth, until they be about forty years of age, after 

 which period no fir plantation which has been pro- 

 perly managed, should be at all disturbed by the 

 operation of thinning. At forty years of age, the 

 trees in a fir plantation should stand at such a dis- 

 tance one from another, as may be considered sutfi- 

 cient to bring them to confirmed maturity upon the 

 soil upon which they are growing ; and this distance 

 of the trees one from another should, as I have for- 

 merly stated, be about one third of their height ; 

 and, indeed, this ought to be as nearly as possible 

 the rule for distance among fir plantations at all 

 stages of their growth, commencing our calculation 

 with the time the trees receive their first course of 

 thinning. 



In many high-lying districts, the trees in a fir 

 plantation may, at forty years of age, be about 

 thirty feet high ; therefore, the distance of such 

 trees at that age, should be as nearly as possible ten 

 feet : and, again, in a more sheltered situation, with 

 a dry and favourable subsoil, they may, at forty 

 years of age, be about sixty feet high; and in such 

 a case, the distance of the trees one from another 

 may be about twenty feet. 



