ON THE MECHANICAL PROPERTIES OF STEEL. 



133 



Exp. III. — -Bar of Steel from the Barrow Haematite Steel and Iron Company 



Mark on bar, " H 3." 



Before experiment. After experiment. 



Height of specimen -968 inch -536 inch. 



Diameter of specimen -72 inch 1-065 inch. 



Area of specimen -4071 sq. in -8906 sq. in. 



Results. — Here the strain per square inch (PJcausing rupture is 225,5681bs., 

 or 100-7 tons, and the corresponding compression (Z^) per unit of length is -45. 

 By formula (13). — The work (m) expended in producing rupture = 50752. 



Exp. IV. (January 1868).- — Bar of Steel from the Barrow Haematite Steel 

 and Iron Company. Mark on bar, " H 1 + ." 



Before experiment. After experiment. 



Height of specimen 1-00 inch -51 inch. 



Diameter of specimen -72 inch 1-08 inch. 



Area of specimen -4071 sq. in -9175 sq. in. 



Results. — Here the strain per square inch (PJcausing rupture is 225,568 lbs., 

 or 100-7 tons, and the corresponding compression {l^ per unit of length is -48. 

 By formula (13). — The work (it) expended in producing rupture = 54136. 



