508 THE STRENGTH 



'XXIX. EXPERIMENT. 



Distance between supports feet, depth of 

 beam 5f inches. 

 Weight of beam = 170i lbs. _ ^^i^ 



Dimensions of section in inches, (fig. to experiment 28.) 



Area of top rib zz 2.2 x .36 =, .79 r, 

 Area of bottom rib = 7.0 x .69 = 4.83. 



Thickness at A = .27 -^ ^i«odi 

 at B = .33 

 at C = .60. 



'^ 



Weights Defections Returned to, 



in lbs. in inches. (weights taken efif.) 



8296 - - - - LOO - - - - .15^, . 



8986 - - - - 1.12 



9676 - . - - 1.27 . 3M 



10366 1.45 M^'^ 



11056 = 4 tons 18 J cwt. With this weight 

 it broke, by tension, 9 inches from the middle 

 of the beam, where there were two small defects 

 in the lower part of the bottom rib : the 

 sectional area of the whol^ defective part being 

 about -fth of an inch. This experiment jjs 

 therefore imperfect. ,,^ 



