94 THE WOODSMAN’S HANDBOOK. 
Growth—Board Foot Volume. 
Table 8 gives an idea of the growth per cent in entire tree vol- 
ume. For trees up to 4 or 5 inches in diameter the board-foot 
volume is, of course, zero, and few log rules give board-foot con- 
tents for log diameters below 6 inches, which means a tree 7 or 8 
inches in diameter (at 4.5 feet from the ground). For small trees © 
the board-foot content shows only about 4 board feet per cubic foot — 
of log; this rises to 8 board feet per cubic foot in large trees. The © 
proportion of waste in bark, top, and stump is also smaller in large — 
trees. For these reasons the board-foot volume growth has an extra 
increase which requires increasing the per cent given in Table 8. 4 
A mill test 7 in white pine, sawing round-edged box boards, showed 
the following relation between total cubic-foot volume increment 
and board-foot increment for trees of different diameters with aver- 
age height growth: 
Relation of board foot 
Diameter of (box-board sawcut) in- 
tree. crement to total vol- 
ume increment. 
Inches. Times. 
L.A 
8 1s 
£2 P22 
18 i Ul 
24 1.0 
| 
So that if the volume growth of a tree in round-edged box boards 
is desired, the growth per cent in the table on page 93 should be 
increased 1.4 times for 6-inch trees, 1.2 times for 8 to 12 inch trees, 
and 1.1 times for 18-inch trees, while for 24-inch trees the board- 
foot growth per cent equals the total volume growth per cent. 
a Made by L. Margolin for the Forest Service in cooperation with the State of | 
New Hampshire. 
