FENCES. 129 



fourth and fifth 5 inches wide. They may be wider or nar- 

 rower, as costj taste, or use may dictate. 



The first, third, and fifth boards are joined on one post, 

 and the second and fourth joined on the next post. 



To find the number of feet of boards required for each 

 rod of post and board fence. 



RULE. Add the different widths of the boards, in inches, 

 together, and divide the sum by 12 for the width in feet ; 

 then multiply the width by 16 J, and the product will be the 

 number of feet, board measure, required for each rod of 

 fence. 



EXAMPLE. Required, the number of feet, board measure, 

 for each rod of fence, 5 boards high, the various widths of 

 the boards being 10, 8, 7, 6 and 5 inches ? 



SOLUTION. 10+8 + 7 + 6 + 5 = 36-^12=3 ft. x!6|=49J 

 feet. Ans. 



To find the number of posts required for a given length 

 of post and board fence. 



RULE. Reduce the number of rods to feet by multiplying 

 by 16J, and divide the product by the number of feet the 

 posts are set apart ; the quotient will be the number of posts 

 required. 



EXAMPLE. Required, the number of posts for a post and 

 board fence 160 rods long; posts set 8 feet apart? 



SOLUTION. 160 x 16^=2640-8=330. Ans. 



