PERCENTAGE COMPARISONS 281 



This shows a deduction of 46^ per cent, as compared with 

 the true contents (over bark). 



But if if inches, the correct bark allowance of i inch to 

 I foot is allowed : 



Contents = 



This shows a correct deduction of 47 J per cent, as compared 

 with the true contents (over bark). 

 By Calliper Measurement : 



By formula d * < in inches > x length in feet. 

 144 



Contents = 



11300 

 " 88^826 



= 127^ cub. ft. 

 or (say) 127 cub. ft. 



This shows an excess of 27 per cent, over the true contents. 

 By Board Measurement : 



Mean diameter at smallest end equals 23 inches (not 

 quite). /. 23 ij = 2i| inches. 



Sectional area = 2i|x2i|x 



4 



= 36305 1 1 



Deduct -^-ths ( = 99-0138) 363-0511 -99-0138 



= 264-0373 



4- by 12 = 22-033 = ( sa y) 22 

 Multiply by length, 28 J x 22 = 621-5 



.*. Contents = 621^ feet (super) board measure. 



This is (say) 6^th times more than the true cubic contents. 



Thus, in the previous example, where the bark allowance 

 was I inch to I foot, and the taper was I inch quarter girth 



