FIR PLANTATIONS. 141 



instances in the thinning of plantations where the 

 coming down of a heavy-topped fir tree Avoiikl have 

 done much damage ; and in such cases, when I ap- 

 phed the chisel in the manner as above stated, the 

 work was safely accomplished. 



At the age proper for the second thinning of 

 any fir plantation, it should never be too severely 

 thmned ; because, at such an age, say at about 

 twenty years old, the trees are generally in their 

 most healthy and rapid state of growth ; and if 

 they should happen to be checked at such a stage, 

 the ultimate value of the whole plantation might 

 be materially impaired, and it is even possible that 

 the whole might be ruined ; therefore it is re- 

 quisite, in all cases, to thin with experience and 

 caution. 



It is in all cases better to thin frequently, and 

 take out a few trees at a time from any given 

 plantation, than to thin at distant periods, and then 

 to do so severely. Many foresters recommend to 

 thin plantations at regular intervals of ten years. 

 To such a method of procedure I cannot agree, 

 because it is evident that no specified time can 

 be given as an interval between thinnings: planta- 

 tions do not grow with equal vigour every year — in 

 some years trees will make strong healthy shoots 

 of young wood, and in others much less. Trees 

 grow more rapidly in a warm season than in a cold 

 one, and, as has been already stated, they are 



