18 BULLETIN 711, U. S. DEPARTMENT OF AGRICULTURE. 
Briefly, scaling, as practiced by the Forest Service, is the measure- 
ment of sound material in the log and relates to quantity rather than 
quality. National forest timber, therefore, is scaled in accordance 
with the defect in the log and not in relation to any particular grade 
of lumber it will produce. On the national forests in Alaska and 
west of the summit of the Cascade Mountains in Oregon and Wash- 
ington, logs up to and including 32 feet in length are scaled as one 
log; lengths from 34 to 64, inclusive, are scaled as two logs' as 
nearly equal in length as possible in even feet, and increasing the 
diameter of the second log according to the taper of the first. 
Greater lengths than 64 feet are scaled as three logs, making the 
division as nearly equal as possible in even feet. 
Timber sale contracts specify a definite overlength for trimming. 
This allowance is adapted to different logging conditions and to 
large and small timber. Three inches overlength may prove suffi- 
cient in small timber where danger from brooming is slight, while 
9 inches or more may be reasonable in sales of large timber or where 
the danger of brooming in driving or chuting is great. 
All diameters are measured inside the bark at the top end of the 
log, being rounded off to the nearest inch above or below the actual 
diameter. Logs which have a diameter exactly halfway between 
inches are thrown to the next lower inch. If logs are not round, 
they are scaled on the average diameter. Several diameters may be 
measured where necessary to obtain a fair average. 
The Forest Service has formulated a number of rules for making 
discounts for defects, realizing that the effect of rot and other de- 
fects upon logs of different species and in different regions varies 
so greatly that no rule for making deductions can be applied in- 
flexibly, and that the constant exercise of good judgment by scalers, 
based upon an accurate knowledge of local timber secured by seeing 
defective logs opened up under the saw, is essential. 
Every timber-sale contract defines exactly the material to be classed 
as merchantable under its terms. 
The methods of manufacture of particular purchasers are not 
taken into account by scalers. No attempt is made to adjust the 
scale to losses due to poor equipment or inefficient methods, to match 
up gains from exceptionally close utilization, or so modify the scale 
as to eliminate losses resulting from selling the log product on a 
different scale. The function of a Forest Service scaler is to deter- 
mine the amount of sound material in the log as uniformly as pos- 
sible, whatever the mill tally or the selling scale may be. The For- 
est Service gives no assurance or promises on the amount of the over- 
run. Systematic checks on the local scale are made by more experi- 
enced scalers of special competence. In case of a serious complaint 
