Part II.] 
Caccia : Development of Sal. 
219 
II, Trees of inferior species, those yielding timber of poor quality, the uses 
for which are limited, frequently cease to increase in value after 
attaining a certain girth. 
III. Trees of particular dimensions, (mine props, hop poles, etc.) may have 
high temporary values which fall as soon as those dimensions are 
exceeded : but the value increment subsequently follows the laws 
above enunciated, increasing .with the diameter. 
IV. The value of a wood increases faster than its volume, since the rate at 
which the value increases depends both on the volume incre- 
ment and on the rise in price per unit of volume. 
\’. The current annual value increment, like the volume increment, steadly 
rises during early youth, reaches a maximum, and then falls : the 
more favourable the locality the earlier will the current annual value 
increment cuhninato. 
VI. Though the mean annual value increment may be said to follow the 
same course as the current amiual value increment it seldom, if 
ever, culminates before the exploitation of the wood. 
VII. In a systematically worked forest with a normal series of age gradations, 
the higher the rotation, the greater the value of the growing stock. 
In other words, the rotation of the highest income seldom culminates 
before the age of exploitation. 
The value of single trees or whole woods of a given age is obtained 
from volume tables* by ascertaining the local prices of the several 
grades of timber and firewood. In this way also Money Yield Tables 
may be prepared : but such tables can only be of purely local or tempo« 
rary application, especially in India. 
Moreover, under existing market conditions, the laws which govern 
the development of the money value of single trees and woods as above 
enunciated do not appear to be altogether applicable to the Sal. Por 
instance, the money value of Sal timber per unit of volume, taking the 
rates levied by the Forest Department at forest depots for trees above 3 
feet in girth at breast-height, does not as a rule increase appreciably 
with the diameter. The following table gives examples of the values of 
Sal timber of various grades : — 
Sec pages lOa aud 109, ante. 
