FIR PLANTATIONS. 129 



CHAPTER IV. 



SVSTEM OF THINNING AND REAKING UP OF FIR PLANTATIONS SYS- 

 TEM OF THINNING AND REARING UP OF MIXED HARD-WOOD 

 PLANTATIONS REARING UP AND THINNING OF OAK PLANTATIONS. 



SECTION I. SYSTEM OF THINNING AND REARING UP 



OF FIR PLANTATIONS. 



In order to point out properly the manner of 

 proceeding with the thinning of fir plantations, it 

 will be neccsary to give a detailed account of how 

 the work should be done at the different stages of 

 the age of any plantation ; and, as I have already 

 stated that no particular age of a young plan- 

 tation can be given as that at which thinning ope- 

 rations ought to commence upon it, the observation 

 of the operator must always be his guide in such a 

 case. Every man who has given his attention to 

 the rearing of forests must have observed, that on 

 some particular soils and situations a young plan- 

 tation may be in a fit state for thinning at eight 

 years of age, while another, composed of the same 

 sorts of trees, and planted at the same time, may 

 not be ready for this operation at twice that age — 



