142 A MANUAL FOR NORTHERN WOODSMEN 



logs jof different sizes, though in a run of logs the results 

 obtained may approximate a fair thing. Very small values 

 are given to small logs, too small by far for normal logs 

 economically manufactured, while beyond about 36 inches 

 in diameter values are given that are above the product of 

 the saw. It crosses the Scribner rule at 25 inches in 

 diameter, the Maine rule at 34. A test made by Dr. J. F. 

 Clark in 1905 in a Canadian band mill cutting sound, 

 straight pine into boards resulted as shown on page 141. 



The Doyle rule is in more general use than any other in 

 the United States and Canada, and is the one printed in 

 recent editions of Scribner's " Lumber and Log Book." 



This rule has been combined with the Scribner into the 

 Doyle-Scribner rule, the figures of the Doyle rule being 

 taken for small logs where the Doyle figures are lower, 

 and of the Scribner rule on the largest logs where these 

 figures are less. This Doyle-Scribner rule has been used 

 largely on hard woods. 



5. Maine, also called Holland Rule. The figures of this 

 rule were derived from diagrams. That is to say, circles 

 6, 7, 8, etc. inches in diameter were plotted and within 

 these the boards that could be sawed, an inch thick with 

 J inch for saw kerf. Not only the boards derived from the 

 inscribed square were reckoned, but the side boards if 

 they were as much as 6 inches wide. No rounding off of 

 the figures was done, so they are a little irregular, but that 

 takes care of itself in a run of logs. 



This rule is used largely in Maine and to some extent 

 elsewhere. It has been carefully tested at the saw, and 

 the conclusions are as follows : Sound spruce and pine 

 logs 12 to 18 feet long, of best merchantable quality, 

 manufactured at a circular saw cutting J-inch kerf will 

 yield in the shape of inch boards just about the number of 

 feet of edged lumber that the rule gives. A band saw will 

 get more, and there will be a larger product if the logs are 

 put into plank or timber. More will also be got the longer 

 the logs run, up to the poinl where they are scaled in two 

 pieces. 



How sawing practice affects the product at the saw was 

 clearly shown by a test made by the United States Forest 



