Forest Mensuration 



57 



For the standard rules, the increment percentage of a tree can be ascer- 

 tained by cubic measure as well as by standard measure. 



If n years are required to form one additional inch of diameter, then 

 the extraordinary percentage of Doyle-increments amounts annually to 



"j/l.OD, wherein D represents the values of Column D in the foregoing 

 table. 



By this factor yl.QD, the cubic volume increment percentage of a 

 bole may be converted, ceteris paribus, into Doyle increment percentage, 

 provided that 



