SCALING PRACTICE 93 



be dropped, throwing logs from 17.6 inches to 17.9 inches into the 17- 

 inch instead of the 18-inch class. 1 



The variations in scaling practice or local "scale" for the different regions in 

 the United States and Canada are shown in Table XVII, p. 94. 



It is seen that the standard set by the U. S. Forest Service is almost nowhere 

 complied with in private operations, and that the departures from this standard 

 work uniformly in favor of the buyer. Except for hardwoods, there is no valid 

 reason for rejecting fractional inches, since these are in most instances already 

 rejected in the construction of the log rule itself (Scribner, § 68), and in any case, 

 the contents of logs of exact inch diameters represent a fair average for logs varying 

 up to j inch larger or smaller. In the same way, it is unfair to measure the 

 smallest diameter instead of the average, for the sawed contents of logs with 

 eccentric cross-sections is little if any less than for round logs, and certainly 

 does not diminish in proportion to the ratio between smallest and average diameter. 2 



Fig. 12. — Effect of rapid taper at small end upon scaling diameter and 

 scaled contents of a log. 



1 The adoption of these two buyers' practices in the scale will result in a loss 

 to the seller which, by the Scribner log rule, amounts to from 5 to 15 per cent, 

 averaging 8 per cent for logs running 10 to the thousand board feet, and 13 per 

 cent for logs running 20 per thousand. The use of the average diameter, and the 

 rounding off of fractional inches are practices fair alike to buyer and seller, and 

 are required by the U. S. Forest Service in selling public timber. 



The practice of reducing unit feet in a log rule to tens, or converting the rule 

 into a "decimal" rule gives a third opportunity for discrimination in favor of 

 the buyer. The correct method is that employed in the Scribner Decimal rule where 

 all fractions above 5 feet are thrown to the 10-foot value above, while those less than 

 5 feet are dropped. But in one section of Maine it is the custom to drop all unit 

 feet scaled by the Maine rule. Thus a log scaling 19 feet would be entered as 

 10 feet. The effect of such a custom on the scale is self evident. 



2 In a contract for sale of logs, the log rule to be used must be mentioned. 

 The practice regarding scaling length, trimming allowance, method of measuring 

 taper or rise on logs of greater than scaling lengths, measurement of diameter and 

 treatment fractional inches should be specified. Otherwise, common custom or 

 scale in the locality will determine what constitutes a proper method. The method 

 of deducting for defects whether by each log separately or by a straight per cent 

 should be agreed upon, and if possible, standard instructions adopted for culling 

 defects. The minimum dimensions of a merchantable log should be defined, both 

 as to length and diameter, and as to per cent of total scale which must be obtained 

 after deducting for defects. 



