724 Forestry Quarterly 



plained how the Scribner Decimal C Rule as originally published 

 was extended to secure board foot contents on larger logs. Espe- 

 cial emphasis is placed on throwing the one half inch diameters 

 to the lowest inch when scahng. "If . . . the average diam- 

 eter is 353^ inches — the log is scaled as a 35-inch log." It has 

 never been clear to the reviewer why a 353^-inch log should not be 

 scaled as a 36-inch log with just as much reason as a 35, or better 

 still, why it should not be scaled 35 one time and 36 the next 

 on a give and take principle. The rules for interior defects are 

 excellent (p. 18), and should be of value even to experienced scalers 

 now that empirical methods are giving way to exact practice. 

 Possibly it might have been well to emphasize the difference be- 

 tween curve allowance in a butt log, as compared with the other 

 logs in the tree, on the grotmd that curves in butt logs (while rare) 

 cannot be allowed for in varying log lengths. 



Under "check scaling" a summary of the scale by the original 

 scaler and by the check scaler is still required, as it should be. 

 But even more emphasis might have been made that a difference 

 between the two scales is not a basis for changing the original 

 scale. There is some question as to whether the original scaler 

 should even be informed of the difference percent. On accoimt 

 of the peculiar psychology of scaling better resiilts may be secured 

 by merely correcting errors in scaling with reference to single logs 

 rather than on the basis whether the scaler averages higher or 

 lower than the check scaler. 



On p. 66 a very complete converting factor table is given which 

 will be of value for statistical purposes, even if individual JBgures 

 may be questioned. The log grading rules (pp. 92-93) are worthy 

 of study, although the reviewer, prefers names for different log 

 classes rather than nimibers. Is not the classification clear, shop, 

 rough, preferable to Number 1, 2, 3? This naming of log grades 

 is followed in the example given on p. 94. 



It is understood that the original manual was written by E. H. 

 Clapp, who should be complimented on the excellence of the 

 presentation of the data. 



According to the Forest Service : 



"The 1916 edition contains no radical changes from that of 

 1915. It was found, however, that the text could be considerably 

 clarified by reconstruction and rearrangement, and the pro- 

 cedtire in some respects was changed. The more important 



