434 THE STRENGTH 



shewed that, in some forms of section, the 

 forces are widely different at the time of fracture. 

 The experiment was made, with the preceding 

 ones, at Messrs. Hatton's Foundry in Salford. 



23. I took two castings, apparently precisely 

 alike, whose dimensions in the section were the 

 same as in last experiment (expt. 4), and placing 

 the ends of each of them upon two props, 4 feet 

 3 inches asunder, broke them by weights in 

 the middle, one with the broad part downwards 

 thus (j-), and the other with it upwards (x). 



The first bore 8| cwt. and broke with 9 cwt. 

 Deflection in the middle with 4 cwt. .6 inch 



The weights were laid very gently on, and 

 the casting shewed no signs of approaching 

 rupture, except a small increased deflection ; 

 but when it broke, a piece flew out whole from 

 the compressed side, of the form below, where 

 AB — 4 inches, and CD = .98 inches, the 



D 



point D at the bottom being in or near to the 

 neutral line. AB was in the direction of the 

 length of the casting, and the weights were 



