270 STRENGTH OF MATERIALS. 



NOTE. When the beam is loaded uniformly throughout 

 its length the result must be doubled. 



When the bar or beam is fixed at both ends and the weight 

 applied in the middle. 



RULE. Multiply the value in the preceding table by six 

 times the breadth, and the square of the depth in inches, 

 and divide the product by the length in feet. 



EXAMPLE. "What weight will an ash beam 8 inches deep 

 by 10 broad and 10 feet long sustain in the middle, when 

 fixed at the ends ? 



SOLUTION. 77 x 60 x 8 2 =295680-^10=29568 Ibs. An*. 



EXAMPLE 2d. What weight will a cast iron bar 2 inches 

 square and 4 feet long support, when applied in the 

 middle, the ends being fixed ? 



SOLUTION. 400 x 12, six times breadth, x 2 8 =:19200-T-4= 

 4800 Ibs. Ans. 



NOTE. When the weight is equally distributed along its 

 entire length, the above results must be doubled. 



WJien the bar or beam is supported at both ends and the 

 weight applied in the middle. 



RULE. Multiply the value in the preceding table by the 

 square of the depth, and four times the breadth in inches, 

 and divide the product by the length in feet. 



EXAMPLE. What weight will a white pine beam 8 inches 

 broad by 6 deep and 6 feet long carry when applied in the 

 middle, the ends being supported ? 



