8 



narrower at one end than at the other. (See diagrams on 

 page 63.) The rule for scaling this form of lumber provides 

 that it must be scaled on the narrow face inside the bark at 

 the place of average width. The determination of the place 

 of average width is left to the sealer, so that it means that a 

 man measuring this kind of lumber must have good judgment 

 and be without bias. 



LOG RULES. 



The contents of round logs are usually expressed in terms 

 of board feet, and a log rule purports to show the number of 

 board feet that can be sawed from a log of given length and 

 diameter. Log rules are of two classes. The first class may 

 be called the theoretical rules, which are based on geometrical 

 or mathematical formula?, where given values are allowed for 

 lumber that must be wasted in slabs and saw kerf, and the 

 remainder figured as usable boards. There are more than 

 forty such rules in use in America, no two of which give the 

 same value to the same log. As they are nearly all meant to 

 apply to square-edge lumber they have no value for use under 

 our local conditions. The second class is made from mill 

 tallies; that is, logs are followed through the mill and the 

 number of board feet each log actually sawed out noted. The 

 results of many logs are then averaged. The log rules printed 

 in this book were constructed in this fashion, and they are 

 commended for use in all transactions for buying or selling 

 logs where the ultimate product is to be in the form for which 

 the log rule is constructed. They are based on conditions of 

 lumbering and sawing found in this State, and are the results 

 of averaging the saw bill of many mills, most of them of the 

 portable kind, having circular saws cutting a inch kerf, un- 

 less otherwise noted. 



