54 NATIONAL FOREST MANUAL TIMBER SALES. 



The rule given for circular rot may be used in determining the 

 amount of loss caused by shake by finding the diam- 

 eter of the portion of the log included within the outer 

 "ring" of shake. If there is at the center of the log a core of sound 

 timber of merchantable size, inside of the shake "rings," the core will 

 be scaled as a log and the difference between its contents and the 

 amount to be deducted is the net deduction from the full scale. 

 Pin dote appears on the cross section at the end of a log in the form 

 of little rotten spots usually scattered in a roughly 



-Fin aote. i -[-* L ' j_ I) 



circular area. Logs containing it may open up 

 poorly, the doty spots frequently converging and forming a mass of 

 poor material. It sometimes extends into knots, and generally, if the 

 visible area affected is 4 or more inches in diameter, it should be 

 deducted as in circular rot. 



Ground or stump rot is found in butt logs, usually appearing in the 



form of brown, dry punk. It seldom extends far into 

 iot r und r stump tne lg> and usually tapers to a point. If it joins center 



rot from above, the defect falls within the center or 

 circular rot class. 



Where stump rot occupies the center of the log to within a short 

 distance of the bark, a sufficient deduction can be made from the 

 length of the log. In addition, a small allowance for the defect 

 may also be made, since it may occur in the log above the section 

 dropped. The responsibility of the sawyers in butting unusually 

 defective logs and in adjusting log lengths so as to eliminate defect 

 should be determined before scaling. 



The sealer must exercise judgment in such cases, considering the 

 relative diameter of the defect as compared with the diameter of 

 the butt and sighting along the log to see if any boards can be cut 

 between the rot and the bark. Where this defect occurs at only 

 one side of the butt, it usually extends only a short distance into 

 the log, and frequently much of it will come out in the slab, espe- 

 cially where there is considerable " flare" or swell. 



Deductions for cat face can be determined by dividing a log into 

 cat face sections as follows: Consider what proportion of the 



length of log is affected; find the contents of this 

 section on a scale stick, then determine the proportion of the section 

 that will be lost in sawing, and deduct this amount. 



For example, in the butt of a 16-foot log with a top diameter 

 of 24 inches, which scales 400 feet b. m., there is a large cat face 

 about 5 feet long which extends to the heart of the log. The cat 

 face tapers toward its top, where it will come out in slabbing, and 

 affects about 4 feet of the log. The 4-foot section affected will 

 contain one-fourth of the log scale, or 100 feet b. m. The defect 

 includes one-half of the 4-foot section, or 50 feet b. m., which should 

 be deducted. Here again judgment must be used. While the defect 

 may extend to the heart at the point of cutting on the stump, it 

 may taper rapidly toward its top and perhaps affect only one-third 

 or less of the section. 



The sealer should never lose sight of the fact that the percentage 



of loss caused by defects located at the side of a 

 * lg is much less than when they occur near the 



center, since in the former case much of the defect 

 will come out in slabbing. This is especially true of the butt of 



