BOARD MEASURE 



141 



factory results. In some matters, especially culling for 

 defects, latitude must be allowed to the sealer. In general, 

 however, practice is weak in the direction of strict mechan- 

 ical accuracy. Reference is made to section VI following. 

 The method of construction, field of use, and relation to 

 saw product of the above named rules are as follows : 



2. Scribner and Decimal Rules. The figures of the 

 original Scribner rule were obtained by drawing diagrams 

 of the end sections of logs 12 to 48 inches in diameter and 

 the boards which in the mill practice of the time could be 

 sawed out of them. It is a very old rule and in wide use. 

 As printed, extended down to 6 niches, it is the legal rule 

 in the state of Minnesota. 



Omitting unit figures of the Scribner rule and taking the 

 nearest tens has given the Decimal rule, so called, legal in 

 Wisconsin and adopted by the United States Forest 

 Service. 



3. Spaulding or Columbia River Rule. This rule was 

 derived by similar methods as the preceding, 1 inch being 

 allowed for saw kerf. It is in more extensive use on the 

 Pacific Coast than any other. 



4. Doyle Rule. This rule was constructed by the fol- 

 lowing formula : Deduct 4 inches from the diameter of 



the log for slab, square J of the remainder, and multiply 

 by the length of the log in feet. This is a very illogical 

 rule and gives results widely varying from saw product in 



