VOLUME AND YIELD. 



37 



TABLE 11. Proportion of heartwood, sapwood, and bark; second growth, Ohio Valley. 



The form of the stem is shown in Table 12, based on the measure- 

 ments of 630 trees. Although the form varies somewhat with dif- 

 ferent species and again with different regions, the table makes it 

 possible to comparp the general form of the hickories with that of 

 other trees; this comparison brings out its extremely slender, slightly 

 tapering stem. The practical value of the table is to supply missing 

 measurements. Thus if the diameter breast-high alone were known, 

 the diameter 15 or 20 feet above the ground could be estimated with 

 some degree of accuracy, or the diameter breast-high could be deter- 

 mined from that of the stump. 



TA BLE 12 . Taper of stem of hickories . 



Diameter breast-high- 

 inches. 



Height feet. 



5. 



JO. 



20. 



40. 



Diameter outside bark inches. 



