NATIONAL FOREST MANUAL TIMBER SALES. 55 



the first log where the flare or swell is considerable at the point of 

 cutting. 



In culling for dote on one side of a log extending to the bark, 

 burns or other defects caused by lightning extending along the side 

 of the log, the sealer should consider how far toward the heart they 

 extend, and by estimating the percentage affected determine upon 

 suitable deductions. 



Since they do not usually run deep and can be mostly removed 

 in slabbing, defects caused by lightning extending spirally along a 

 log do not affect the scale. The percentage of loss is proportionately 

 greater in small logs than in large ones. 



Punky or unsound Where a shell of unsound sap occurs, only the 

 sa P- sound heartwood will be measured. 



Sound blue sap does not render a board unmerchantable, but the 

 Blue ga sealer should be certain that it is not insect eaten. 



The fault occurs most frequently in dead trees, but 

 may sometimes be found to affect dying trees. Oftentimes logs 

 containing it are slightly punky at the outside, and as a rule, if 

 the sealer in measuring the diameter includes the sap on one side 

 of the log only, discarding the other sap, the result will be satis- 

 factory. 



Deep checks or seams are usually found in dead and dry trees and 

 affect the scale in varying degree, depending upon the 

 sens p cks r number of checks, their depth, etc. Almost always 

 they extend through the sap and frequently into the 

 heartwood. Where they affect the sap alone, the rule for culling 

 for defective sap will apply; where the checks are small, it is fairly 

 certain they affect the sap wood only; but when they are of con- 

 siderable width they usually affect the heartwood, and proper deduc- 

 tions should be made. 



Where only one deep, straight check occurs in a log the loss is very 

 small, but where many seams are found the method given for use in 

 the case of deep spiral checks can be followed. 



Where deep spiral checks are found, the sealer will measure the 



diameter of the portion of the log included within the 



checks 6 P s P * r a 1 largest circle which can be described on a cross section 



without being materially affected by the checks and 



class as defective all that part of the log outside the area defined by 



the circle. 



Rot in the log is sometimes shown only by an examination of the 

 Dote appearing in knots, and the only method of determining the proper 

 knots - deduction is to see such logs "opened up." 



When rot appears at the ends of a log and also in the knots, the 

 deduction depending on the number of knots affected, their size, 

 position, etc., should be from 10 to 50 per cent greater than when it 

 appears at the ends alone. When dote appears in the knots, it indi- 

 cates that the area of rot enlarges in the portion of the log near the 

 knots. 



The percentage of a log affected by sweep or curve varies acccording 

 curve or swee ^ ^ ie diameter of the log. An amount of curve that 

 might cull a very small log would not necessarily 

 cause the rejection of a larger log. 



The sealer should, when possible, sight along curved logs, noting 

 where the saw would square the log sufficiently to enable boards to 



