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 beeti 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 sealer 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 sealer 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 sealer 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. 



