140 A MANUAL FOR NORTHERN WOODSMEN 



Spaulding, and the British Columbia are printed in 

 this work (see pages 243-260). The International rule, 

 devised by Dr. Judson F. Clark, formerly forester of On- 

 tario, is also given (page 254). In regard to these rules 

 and their relation to log measurement and saw product 

 several general observations may be made. 



(1.) On sound, smooth, soft-wood logs when manufac- 

 tured according to the best present practice, the figures of 

 all the commercial rules are conservative with the exception 

 of the Doyle rule on very large logs. This is especially 

 true with reference to small logs. 



(2.) Board rules give to large logs a greater valuation in 

 proportion to cubic contents (actual amount of wood) than 

 to small ones. Thus the Scribner log rule to 8-inch logs 

 of small taper allows five feet per cubic foot of wood con- 

 tents; to 16-inch logs seven feet, to 30-inch logs eight feet. 

 This principle is a just one for logs that are in fact to be 

 sawn, because the waste in manufacturing in the case of 

 small logs is much greater, but on this account a board 

 rule is not a just measure for logs designed for pulp or 

 other such uses. 



(3.) The rules are adapted to use on short logs with little 

 taper. When logs are long enough to be cut in two for 

 sawing, or to yield side boards for a part of their length, 

 to derive contents from length and top diameter is not a 

 fair thing. In such cases a second measure of diameter 

 should be taken, and this can be done accurately only with 

 a caliper. Allowance for " rise " or toper, whether for each 

 log by judgment or according to some rule agreed upon, 

 is more or less inaccurate and should be resorted to only 

 in case of necessity. It may be said as a general rule that 

 20-foot lengths are as long as it is safe to scale logs in. 1 



On the other hand, since strongly tapering logs in almost 

 every case are rougher than those of gentle taper, varying 

 taper in logs of reasonable length is largely neutralized 

 by quality. 



(4.) There is wide variation in the details of scaling prac- 

 tice, and a trustworthy rule in consequence may, in the 

 hands of an unskilled or careless man, give very unsatis- 

 1 Except in the case of PaciBc Coast timber. 



