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SQUARE TIMBER. 65 



To measure round timber. 



RULE. Take the girth in inches at both the large and 

 small ends, add them, and divide their sum by two for the 

 mean girth ; then multiply the length in feet by the square 

 of one-fourth of the mean girth in inches, divide the product 

 by 144, and the quotient will be the contents in cubic 

 feet. 



EXAMPLE. What are the cubic contents of a round log 

 12 feet long, 54 inches girth at the large end, and 34 at 

 the small end ? 



SOLUTION. 54+34=88-^-2=44 inches, mean girth. 



Then 12 length x 121 inches (the square of \ mean 

 girth) = 1452 -=- 144 IO T ^- cubic feet. Am. 



SQUARE TIMBER. 



To measure square timber. 



RULE. Multiply the breadth in inches by the depth in 

 inches, and that by the length in feet, and divide the pro- 

 duct by 144, and the quotient will be the contents in cubic 

 feet. 



EXAMPLE. What is the cubic contents of a square log 

 12 feet long by 20 inches broad and 18 deep ? 



SOLUTION. 20 x 18 = 360 x 12 = 4320 -=- 144 = 30 cubic 

 feet. Ans. 



