GROWTH 



5 



The height of the great majority of old trees 

 measured was between 100 and 120 feet, and 

 the diameter was from 20 to 30 inches. 



In these mature trees the percentage of wood 

 which cannot be cut into logs is comparatively 

 small. In most cases logs are considered mer- 

 chantable which have a diameter of 8 inches at 

 the small end. Very often logs are taken down 

 to 7 inches at the top, or, in the suppressed 

 trees, which are almost without branches, even 

 to 6 inches. The stumps are, on an average, 

 about two feet above the level of the ground. 

 The spread of the roots below this point is so 

 great, and the difficulty and expense of cutting 

 close to the ground on steep slopes so serious, 

 that in most cases a shorter stump is out of the 

 question. 



Up to a certain point the percentage of mer- 

 chantable timber in a tree increases with the 

 diameter. From a study of trees over 100 years 

 old, the following figures were obtained : 



Diameter breast-high, in inches. 









10 12 14 16 18 20 22 24 26 28 30 32 



34 



36 38 



40 



Percentage of merchantable timber, excluding bark 



AND 



BRANCHES. 





84.5 87 89 90 91 91.5 92 92.5 93 93.4 93.7 94 



94 



94 94 



94 



It appears from this table that only 6 per 

 1* 



