ON THE MECHANICAL PROPERTIES OF STEEL. 



127 



Exp, IX.— Bar of Steel from the Barrow Haematite Steel and Iron Company. 

 Elongations taken on 8 inches length. Mark on bar, "11(3 + ." 

 Diameter of specimen -772 inch. Area -4677 square inch. Reduced 

 diameter after fracture -581 inch. Area -3651 square inch. 



Results. — Here the breaking- strain (PJ per square inch of section is 

 75,120 lbs., or 33-53 tons, and the corresponding elongation (Z^) per unit of 

 length is •I. By formula (13). — The work (u) expended in producing rup- 

 ture = 3756. 



Exp. X. (April 1869). — Bar of Steel from the Heaton Steel and Iron Company, 

 Langley Mills. Elongations taken on 8 inches length. Mark on bar, 

 "1." Diameter of specimen -748 inch. Area -4394 square inch. 

 Eeduced diameter after fracture -748 inch. Area ^4394 square inch. 



Results. — Here the breaking-strain (PJ per square inch of section is 93,545 

 lbs., or 41^761 tons, and the corresponding elongation (ZJ per unit of leno-th 

 is -0390. By formula (13). — The work (u) expended in producing runture 

 = 1824. ° ^ 



