144 THE REARING OF 



At sixty years of age, the wood of the pine and 

 fir tribes is generally considered to be in its most 

 valuable and solid state as timber ; it is then heavier, 

 and more full of resinous matter than at any other 

 stage of its existence ; consequently, at that age, if 

 the object be a crop of valuable timber, the tree 

 should be cut down, and disposed of as may seem 

 best. But if the proprietor have in view the giv- 

 ing of shelter to his lands, which is generally one 

 end aimed at by improving proprietors, the plan- 

 tation may be allowed to stand for other twenty 

 years, after which period the trees will begin to 

 become lighter in their wood, and many will then 

 be showing marks of natural decay, and the whole 

 plantation will of course be generally speaking of 

 less value than it was at sixty years' standing. 

 However, this is not always the case ; for very much 

 depends upon the nature of the soil and situation 

 upon which the crop of wood may be growing, 

 as to whether that may be high or low lying, dry 

 or damp. In a high situation, with a good dry 

 bottom, I have seen excellent fir trees at one hun- 

 dred years old ; while, upon the other hand, I have 

 seen firs beginning to show symptoms of rapid 

 decay at fifty years of age, and in many cases 

 even at a much earlier age, which was in a low 

 and rather moist situation, and without a free cir- 

 culation of air. 



It very frequently happens that fir plantations 



