172 A MANUAL FOR NORTHERN WOODSMEN 
board feet, or cords); the results have been averaged, 
evened by curves, and then the board-foot tables have 
been discounted by a small percentage to allow for normal 
defects of form and quality. Cutting practice that is 
economical, but not extreme, has been supposed through¬ 
out, the idea being to get, as nearly as possible, a conserva¬ 
tive figure for good and economical practice. 
In applying all these tables, considerable defects must be 
allowed for in the form of a discount. It is further to be 
clearly understood that they apply to timber as it runs 
and may be considerably off as applied to single trees. 
In volume tables for hard woods merchantable length 
is in most cases preferable to total height as a factor 
because these trees characteristically spread out at the 
top, at once rendering total height hard to measure and 
destroying utility for lumber. Such tables also, because 
of greater irregularity of form and greater liability to 
defect in hard woods, are in general less trustworthy than 
soft wood tables. Several “graded volume tables,” 
classifying the yield of trees by lumber grades, are in 
existence, but their utility apart from the local conditions 
in which they were constructed does not seem clear. 
The way in which these volume tables may be tested 
and made to conform to the practices of any given locality 
is illustrated as follows: 
A spruce property is to be explored on which cutting and 
scaling methods are as follows: — Timber runs up to about 
20 inches in diameter and 75 feet in height; trees are cut 
down to the size of 12 inches on the stump or 11 breast high. 
Logs cut for saw lumber, one log from a tree, cut off where 
it will scale best. Logs are therefore seldom over 40 feet 
long and run from that down to 28 or 30. Scaling done 
with Maine log rule. If a log is 26 feet long or under, it is 
scaled as one log with the top diameter inside bark; if 27 
to 30 feet, as two logs of equal length giving the butt log 
an inch larger diameter than the top; from 31 to 35 feet in 
the same way but allowing 2 inches “rise,” and 3 inches on 
log lengths of 36 to 40 feet. In addition a level discount 
of 10 per cent is made on all logs to cover defects. 
A half day’s time spent following the loggi ng crew and 
