SECTION VI— SCALING 



PROBLEM 21. (Field.) Scaling Logs. 



Explanation: The method of scahng sound logs free from any defect or 

 malformation is very simple. All it requires is that the diameter inside the 

 bark at the small end of the log and the length of the log be measured and 

 with these two measurements the corresponding volume in board feet may be 

 found on a scale stick or in a table giving contents of logs according to the 

 log rule used. Should the lengths of logs to be scaled be limited to a certain 

 maximum length, logs longer than this length should be scaled in two sections 

 of as nearly equal even-foot lengths as possible, the shorter length to be 

 taken at the small end of the log. The diameter of the section nearest the 

 large end of the log should be increased over the diameter at the small end 

 by an amount corresponding to the taper, estimated for each log. The sum 

 of the volumes of the two sections will give the volume of the log. 



However, no method of scaling is accurate unless the sound volume is 

 discounted to allow for defects which may occur in the log. The following 

 formulae and tables together with an explanation of the method of their use 

 will demonstrate typical methods of allowing for defect in scaling. 



FormuloB for Scaling Defect 



Pitch Seams 



OC^C^^i^E^ T = DDXL 



V 12 7 5 15 



W= width of seam across end of log, inches; 

 A = waste thickness, inches; 

 12 = dividing factor, to reduce to B.M. 

 DD = defect deduction per lineal foot in feet B.M, 

 L = length of defect, feet; 



1^ = reducing factor, to allow 20 per cent for sawkerf; 

 T = total number feet B.M. defect caused by seam. 



