PRACTICE OF TIMBER ESTIMATING 
205 
log markets and timber enters the commercial field in 
the shape of lumber with its great range in quality and 
value. Here the Forest Service, endeavoring in its own 
business to get away from the judgment of the individual 
applied in too broad a way, has started a line of inquiry 
that should in time prove serviceable to business. Log 
grades in this case again are made the basis to which the 
field man works, but mill and yard studies, carrying the 
product of those logs through the process of manufacture 
to point of sale, afford a means of going further, to an 
estimate of lumber quality and value. Definitions of the 
log grades that have been formed for yellow pine follow, 
and brief notes on the yield of those grades may be serv¬ 
iceable to some, although, with a small field covered, it 
has been found already that logs graded by the same man 
under the same rules vary considerably by locality in 
their yield of high grade lumber. 
Yellow Pine Log Grades of the U. S. Forest Service. 
Clear logs shall be 22 inches or over in diameter inside 
the bark at the small end and not less than 10 feet long. 
They shall be reasonably straight-grained, practically 
surface clear, and of a character which in the judgment 
of the scaler are capable of cutting not less than 25 per 
cent of their scaled contents into lumber of the grades of 
C Select and better. 
Shop logs shall be 18 inches or over in diameter inside 
the bark at the small end, not less than 8 feet long, and 
which in the judgment of the scaler are capable of cut¬ 
ting not less than 30 per cent of their scaled contents 
into lumber of the grades of No. 2 Shop and better. 
Rough logs shall be 6 inches or over in diameter inside 
the bark at the small end and not less than 8 feet long, 
having defects which in the judgment of the scaler pre¬ 
vent their classification into either of the two above 
grades. 
Logs cut from rather large and high class timber at 
different points of interior Oregon, graded according to 
the above rules, have yielded as follows: 
Clear logs 60-65 per cent No. 2 Shop and better, about 
half of it of grades B and C Select, 
