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STATE BOARD OF FORESTRY. 



Its Application. 



The above formula when applied to conditions existing at the Red 

 River Lumber Company's mill in Lassen County, California, gave 

 results shown in the following table. The value of a determined at this 

 mill is extremely small, due to the fact that slabs were cut very thin 

 and edgings were graded as moulding stock, also to the fact that short 

 lengths were cut from logs where taper was great enough to permit it. 

 The formula was first applied to 16' logs, thus getting the taper in 16' 

 included with the slabs. Volumes in board feet of logs of other lengths 

 were then figured with a taper allowance of 1" in 8'. 



TABLE 1. 

 formula : 



The McKenzie Log Rule, based upon the following 



Where 

 Where 

 Where 

 Where 



48 



k = saw-kerf = ". 

 k = average width of lumber = 12". 

 t = average thickness of lumber %". 

 D = average diameter of log inside bark, small end, in 

 inches. 



Where 

 Where 

 Where 



L= length of log in feet. 



C = 2 = constant allowed for excessive taper occurring 



in small logs. 

 Where B. M. volume in board feet. 

 Where n = 3.1416. 



With these values substituted, the formula becomes .942(1) I) 2 

 + 2 = B.M..for 16' logs. 



Table based upon 16' logs. Taper allowance of 1" in 8' made 

 for other lengths. 



