98 



CURVES 



CURVES FOR THE YIELD OF WHITE PINE 

 GROUPS IN BOARD FEET. 



These curves are marked by a very late be- 

 ginning and a very rapid, uniform, and long- 

 sustained rise. On a locality of grade I, a White 

 Pine acre which began with 2,500 feet at 40 

 years will reach 78,000 feet at the age of 250, and 

 will still be growing at the rate of about 1,000 

 feet every six years. 



If the age of a White Pine group is found by 

 the curves in Plate II, its stand in board feet 

 may be obtained from the present Plate, and its 

 future increment in the same unit may then be 

 seen at a glance. This Plate will also be found 

 useful in arriving at the relation between the 

 future value of Pine land and the expenses 

 chargeable against it for protection, interest, 

 and taxes. By balancing the probable rise in 

 taxes against the probable rise in the value of 

 stumpage, a very correct idea of the commercial 

 wisdom of holding Pine lands for their future 

 increment in lumber may be obtained. The 

 result reached will be based on actual measure- 

 ment and calculation, and will be correspond- 

 ingly reliable. 



