108 



THE SCALING OF DEFECTIME LOGS 



ner and Spaulding Rules, were based on a minimum width of board of 

 not less than 6 inches. Present practice permits the sawing of 4-inch 

 strips. In deducting for defects by diagram, the latter practice is 

 used, and portions of the log which will yield 4-inch strips are scaled, 

 provided these dimensions lie within the cyhn- 

 der and do not include taper. A rotten butt 

 with 6 inches of sound wood will be a total cull 

 unless the inscribed area of the top or small 

 end of the log contains within it at least 4 inches 

 of sound wood. 



In theory, this rule must be modified for 

 deductions which take the form of slabs, since 

 the original diagram or scale rejected all boards 

 below 6 inches in width. This case is illustrated 

 in Fig. 14. 



The minimum length of merchantable board 

 should first be standardized or agreed on in 

 scaling. Formerly a defect at one end of a 

 standard log, say 16 feet long, would cull the 

 boards affected for their whole length. But 

 where boards of 6- or 8-foot length are merchant- 

 able, defects which leave a sound length equal 

 to these minimum boards will be scaled only 

 for the actual length of the part affected. This 

 rule affects the results for nearly all forms of 

 defect. Standard minimum lengths are im- 

 portant in scaling crooked logs. The standards 

 now in use for saw timber vary from 6 to 10 

 feet with a tendency to become shorter. 



91. Interior Defects. Unsound defects may 

 be classed as interior, causing waste in the interior 

 of log; side or exterior defects, causing waste 

 at the surface or outside; and defects in form, 

 i.e., crook, in otherwise sound logs, causing 

 waste in sawing straight lumber. Interior defects are due to rot, 

 shake, seams or checks, and worm-holes. The defect may extend 

 through the entire log, or be present only at one end. It may be cir- 

 cular, and regular in form, or irregular in form and extent. 



Center Rot. Circular defects in the form of either rotten or hollow 

 logs, or ring shake, if they extend through the log, will be measured not 

 at the small but at the large end, provided the log is not over 16 feet 

 long. For longer logs the average of the dimensions at butt and top is 

 taken. If only one end is affected, the diameter of the defective portion 



Fig. 14.— The boards 

 lost are measured in- 

 side the smaller in- 

 scribed circle repre- 

 senting the top diam- 

 eter. Three boards 

 are affected, 4 inches, 

 6 inches, and 8 inches. 

 The 6-inch board is 

 deducted. If the min- 

 imum width of board 

 utilized is 4 inches, a 

 4-inch strip is de- 

 ducted from the 8- inch 

 board. But the 4-inch 

 strip on the margin 

 was not scaled in the 

 original diagram and 

 should be omitted, as 

 constituting over-run 

 by this log rule. In 

 ordinary scaling prac- 

 tice this distinction 

 would probably be 

 overlooked as too 

 great a refinement. 



