38 LOG RULES BASED ON CUBIC CONTENTS 



TABLE 11— Continued 



Log rule 



i I 



Basis of measure-; Per cent of scale! Per cent deducted 

 ment of cylin-1 if measured at from ' contents of 



der, in applica- 

 tion of rule 



at 

 small 



end. 



Per 

 cent 



at 

 middle 



Per 



cent 



other point 



at 

 middle 



at 

 small 

 end 



cylinder to ob- 

 tain contents 

 given in rule — 

 For rules applied 



at j at 

 small ' middle 

 end 



Log Rules. — Continued 

 22-inch standard, converted 



ratio 1 to 250 ft. B.M 



Market, or 19-inch standard 



converted, ratio 1 to 200 ft 



B.M 



Vermont , 



Vade Mecum (Stillwell's) 



Square of Two-thirds 



Ake 



French's (Los Angeles) 



Calcasieu 



Blodgett, converted, ratio n5 



to 1000 ft. B.M 



Blodgett, converted, ratio 106 



to 100 ft. B.M 



Cuban One-Fifth 



Orange River 



Maine cubic rule, converted 



185 cu. ft. per 1000 ft. B.M. . 



Cumberland River 



Delaware or Eastern Shore. . . 



65.6 



65.1 

 63.4 

 63.2 



62.4 



57, 



56.2 

 50.9 



45.2 

 42.4 



56.5 

 52.2 



51.9 



50.1 



45.0 



58. 9 



58.4 

 56.9 

 56.7 I 



! 62.9 



56.0 

 51.9 



50.4 

 45.7 



40.6 

 38.1 



I 58.2 



57. 



55.9 



50.1 



34.4 



34.9 

 36.6 

 36.8 

 37.1 

 37.6 

 41.8 

 42.2 



42.2 



43.8 

 44.1 

 49.1 



49.9 

 54.8 

 57.6 



41.1 



41.6 

 43.1 

 43.3 

 43.5 

 44.0 

 47.8 

 48.1 



48.1 



49.6 

 49.9 

 54.3 



55.0 

 59.4 

 61.9 



Of the cubic log rules expressed in board feet, the Constantine is frankly a cubic 

 rule, converted from the cubic foot, but based on the small end of log. The rest 

 are suitable neither for cubic contents nor for board feet, since they do not express 

 the former nor do they measure the latter correctly (^Chapter \). 



These rules are all convertible into cubic units or from one to the other, when 

 based on cylinders measured at the same point. 



wD- 



The formula. Board feet = (l— C) L, can be used to obtain the values for any 



48 



of these rules, by sub.stituting for C the per cent given in the last two colunuis of 

 Table II, e.g. 



