36 



Conditions affectiiig Growth 

 A 



Fig. 8. 



Diagram of a trunk 

 with a branch. 



Fig. 9. 



A board cut from the tree in 



Fig. 8, cut along the line 



AB, showing the knot. 



A good height-growth, a restricted crown with few large 

 branches, and a clean cylindrical stem, are characteristic of trees 

 growing in a dense wood. This type, therefore, furnishes the 

 greatest amount of valuable timber. 



The object of thinning is to regulate the growing space of each 

 tree — " the room it has to grow in," to use an ordinary expression — 

 in order that the largest possible amount of high quality timber 

 may be produced per acre each year. 



It is hardly possible to give figures regarding the number of 

 trees to be removed in the thinnings at given periods, as these will 

 vary according to the fertility of the soil, and to the suitability to the 

 locality of the species planted. This is one of the details where the 

 advice of an expert should be taken ; he, having made an 



