92 Forestry Quarterly 



Doyle Rule. The constant for taper was +2. This gave a 

 formtdaof .942 (D — 1) ^+2 = B M for 16-foot logs. A taper 

 allowance of 1" for 8-foot was allowed for other lengths. 



The resultant log rule shows an almost constant excess of be- 

 tween 6 and 7 per cent over that given in Clark's International 

 Rule, a result largely attributable to the \}/i" thickness of lumber 

 used as against 1" in the International. For other widths of 

 saw and thickness of dimensions, different resiilts would be 

 obtained. 



For adoption as a State standard, these variable or elastic 

 factors would have to be eliminated and a definite agreement 

 reached. There cannot be as many log rules as there are different 

 factors in sawing. The function of a log rule is to set a commercial 

 standard for measurement. There will always be overrun or 

 underrun from most mills, for any log rule, preferably the former. 

 Inaccurate and falsely constructed log riiles, however, should 

 eventually give way to rules based on correct principles, and this 

 bulletin is an aid to those seeking this result. 



After analyzing the principles and formulae applying to many 

 standard log rules now in use, the author shows when it is possible 

 to convert a volume table of tree contents expressed in one rule 

 into terms of a different rule, and when this transformation is not 

 possible. This depends upon the construction of the respective 

 rules. Tables made on the following riiles can be so converted by 

 using the proper factors, which are discussed : 



Constantine, Saco River, Derby, Square of Three-fourths, 

 Partridge, Vermont, Inscribed Square, StUlwell, Ake, Square of 

 Two-thirds, Two-thirds, Orange River, Cimiberland River, 

 Bangor, Boynton, Parsons, Warner, Spaulding, Wilcox, Ropp, 

 Favorite, Nineteen-Inch Standard, New Hampshire, Cube Rule, 

 Twenty-two-inch Standard, Twenty-four-inch Standard, Seven- 

 teen-Inch Rule. 



The Doyle and Scribner Rules cannot be transposed. 



H. H. C. 



Forests, Forestry, and the Lumber Industry in the United States 

 oj America. By M. Tkatchenko. Petrograd, Russia, 1914. 



The author of this book, containing 273 pages and a large number 

 of splendid illustrations and maps, is known to many foresters 

 in this country. Mr. Tkatchenko spent almost an entire year in 



