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CHAPTER XL 



RULES FOE THINNING. 



1. Thinning should be done to preserve the lower 

 branches from withering, and encourage rooting of 

 the tree. 



2. Thinning is done to remove small, weakly, 

 and inferior trees, that those of superior growth 

 may have full advantage of space for their develop- 

 ment. 



3. Thinning is done to regulate the distances of 

 the trees from one another, and to preserve certain 

 kinds by removing other kinds from them. 



4. The object of thinning is to prevent rather than 

 cure, and therefore should be done while the trees are 

 comparatively young and small of growth. 



5. Thinning ornamental plantations is done dif- 

 ferently, because for a different purpose than profit- 

 able ones. For ornament, the branches are preserved 

 vital throughout their growth, even to mature old age ; 

 while for profit they are to decay and fall off while the 

 tree is yet comparatively young. 



6. Thinning advanced pine and fir plantations is \ 

 very injurious to them, because it allows currents of 

 air and rays of light to penetrate, heat, and dry the 

 soil, while the roots underneath are not prepared for 



