90 CURVES 



CURVES FOR THE DIAMETER OF THE AVERAGE 

 TREE IN WHITE PINE GROUPS. 



From this table it is possible to find the ap- 

 proximate probable age of a group of White 

 Pine by means of callipers or a tape measure. 

 Thus, if the diameter of an average tree of an 

 even-aged group is found to be 16 inches, the 

 probable age of the group will be 98 years in a 

 locality of the first grade, 186 if the locality is 

 poor, and 132 years if it is intermediate. 



