116 



THE SCALING OF DEFECTIVE LOGS 



form a dead streak causing a surface defect, sometimes of considerable 

 proportions. 



Breakage. The deduction for splits and breakage caused by felling 

 is made either by slabbing or by shortening the log length, to remove 

 the portion ruined by the breakage. Where this waste is avoidable, 

 owners stipulate that it shall be scaled as sound, but purchasers of logs 

 insist on the deduction. . In the Pacific Coast States, breakage may 

 exceed 25 per cent of the scale. 



93. Crook or Sweep. Crook may be defined as a rather abrupt 

 bend in the log at a given point, while sweep is a more gradual bend 

 extending over a considerable length. Crooks occurring near the ends 

 of a log may be allowed for in scaling by shortening the scaling length. 

 With gradual sweep affecting the form of the log as a whole, a different 

 deduction is necessary. The effect of sweep or crook upon the scaled 

 contents of the log (§ 52) depends directly upon the minimum length 

 of boards utilized and scaled, or upon the acceptance of fixed minimum 

 scaling lengths for the logs. If it is assumed that the minimum board 

 governs the scale, deductions for crook or sweep will seldom be made, 

 since almost complete utilization can be obtained of sound crooked 

 logs by the box factory. But if the scale of a log is based on the output 

 of boards of the standard scaling lengths into which the logs are cut, 

 and short lengths cannot be utilized, crook or sweep will cause deduc- 

 tions in scale when it exceeds the normal minimum permitted. 



When logs crook in but one plane, the loss in sawed lumber is proportional 

 to the relation which the total deflection or crook bears to the diameter of the log, 

 and does not depend on the number of inches of crook independent of size of log; 

 e.g., for a 12-inch log a 6-inch crook is 50 per cent of the diameter'but for a 24-inch 

 log, a. 6-inch crook is but 25 per cent of the diameter, and a 50 per cent crook 

 indicates a crook of 12 inches. 



By diagram checks, and sawing, the per cent of waste due to sweep for a given 

 total number of inches of crook per log is found to be independent of the length 

 of log, and to show the following results: 



TABLE XVIII 

 Deductions for Crook and Sweep 



