MEASUREMENT OF LOGS AND OTHER FOREST PRODUCTS 1 25 



Rotten Sap. — The sound heartwoocl only is measured on 

 logs having this defect. 



Stained Sap. — Sound stained sapwood of most species is 

 merchantable if it has not been attacked by wood-boring insects. 

 The full scale is given for sound material, but when the sap- 

 wood is worm-eaten the heartwood only is measured. 



Checks and Seams. — These are found chiefly on dead timber 

 from which the bark has fallen. They usually extend through the 

 sap, and on timber that has been dead for some years they may 

 extend well toward the center of the tree. Where the checks are 

 small the scaling diameter is taken inside the sap, while on logs 

 with wide checks a further deduction must be made in accord- 

 ance with the scaler's judgment. 



A single deep check can usually be sawed out by the loss of one 

 or two boards and their contents only should be deducted. 



Spiral Checks. — Where deep spiral checks occur the scaling 

 diameter is that of the largest circle that can be secured without 

 the inclusion of the checks. 



Crook or Sweep. — The percentage of loss from this defect is 

 greater on small logs than on large ones. The contents of the 

 log may be determined by finding where the saws will square the 

 log sufficiently to enable boards of the narrowest merchantable 

 width to be cut. If the sweep is pronounced, a few short boards 

 may be secured from the slab, in which case their estimated 

 board-foot contents are added to the scale of the log. 



Crotches. — Logs with crotches near the end are reduced in 

 length sufficiently to eliminate the crotch. The scafing diam- 

 eter is taken just below the enlargement caused by the fork. 



Rafting Pinholes. — These are usually about 2 inches in diam- 

 eter and located near the ends of the log. They can generally 

 be removed by wasting the ends, or portions of a few boards, 

 provided the log is sawed in an economical manner. The only 

 guide to discounting defects of this character is the scaler's 

 judgment. 



LOG GRADES 



Logs that are brought into large markets for sale are classified 

 into grades that have been adopted by associations. Printed 



