40 SCALING LOGS 



greater will be the amount of waste. Sometimes a seam at one end of the 

 log will be at right angles to its position on the opposite end. If the seam 

 shows on one end only, the scaler should estimate the length it extends into 

 the log .and take as the width of the seam its width as it shows. If the seam 

 shows at both ends of the log the width of the seam should be taken at Avhich- 

 ever end it is the greatest. 



Measure the width of the seam across the end of the log and the inches 

 of waste that will result from sawing out the seam. Multiply the width of 

 the seam by the thickness of the waste, divide by 12, and multiply the result 

 by ^, which will give the number of feet B.M. defect per lineal foot. Multiply 

 this by the length of the defect and the result will be the total number of feet 

 B.M. defect caused by the seam.* 



Pitch Ring. — To determine the amount of defect in a log with a full 

 pitch ring the scaler should first determine if the ring shows on both ends of 

 the log. If it does not show on both ends he should estimate the number 

 of feet it extends in the log, and then measure the diameter of the ring. If 

 it shows on both ends he should average the diameters of the rings on both 

 ends. Care should be used in getting this average diameter in swell butted 

 logs so as to get a fair average, for the ring generally tapers with the swell and 

 if the swell is very great the measured diameter will be too large. 



Multiply the diameter of the ring thus obtained by 3.14 to obtain the 

 circumference and then measure or estimate the number of inches of waste 

 necessary to saw out the ring — the inches of waste depending upon the irregu- 

 larity of the ring. When two rings occur close together a large factor of 

 waste must be taken as no lumber can be cut between the rings. 



Multiply the circumference by the thickness of waste, divide by 12 and 

 multiply the result by ^. This will give the number of feet B.M. defect 

 per lineal foot. Multiply this result by the length of defect and the result 

 will be the total number of feet B.M. defect caused by the pitch ring. 



Rot. — To determine the amount of defect in a log with center or stump rot, 

 the scaler should first determine if it shows on both ends of the log. If it 

 does not show on both ends he should estimate the number of feet it extends 

 into the log and then measure its diameter. If it shows on both ends he should 

 average the diameters if the rot is uniform throughout the length of the log. 

 Care must be taken with swell butted logg to get an average diameter as the 

 rot usually tapers very rapidly in such logs. When such logs have rot of 

 large diameter at one end and rot of small diameter at the other end it is 

 well to divide the length of the rot into sections and give each section a 

 diameter estimated according to the taper of the rot. Each section would 

 then be treated as a unit by itself and the total of the defect for each would 



* Since in scaling with most log rules all material outside the cylinder represented by the 

 top end diameter is considered as lost in slabbing, a defect which shows at the butt end of a 

 log should never be taken as larger than the top diameter of the log unless the log is scaled 

 in two sections, as explained in Problem 12. In this case the defect at the butt of the log 

 should not be taken as larger than the top diameter of the butt section. 



