DISCUSSION OF LOG RULES. 53 



APPENDIX. 



How to Adjust the McKenzie Log Rule to Conditions Existing 



at Any Mill. 



This can best be shown by assuming a set of conditions and then 

 reducing the rule from its general form to a special form in accordance 

 with whatever the limitations imposed may be. For example, assume 

 the following : 



Mill output for period of three months : 



190,000 bd. ft. of 12" X 12" cut 12 1/4" X 12 1/4" 



Width of saw kerf == 1/8" 



Average taper (not including butt logs or top logs) 



= approx. 1/2" in 8' 



Average thickness of slabs and edgings at small end of logs = 5/8" 

 To determine a special form of 



k)-wtl 



&) J 



L C==BM 



' x 12 



which will conform to the above milling conditions and character of 

 timber. 



