ON THE MECHANICAL PROPERTIES OF STEEL. 255 



Exp. XVII.— Bar of Steel from Messrs. Naylor, Tickers & Co., Sheffield. 



Mark on bar "Y.T." 



Before experiment. After experiment. 



Height of specimen -992 inch. .... -605 inch. 



Diameter of specimen '72 inch. -840 inch. 



Area of specimen -40715 sq. in -55417 sq. in. 



Results. — Here the strain per square inch (P^) causing rupture is225,5681bs., 

 or 100-7 tons; and the corresponding compression (l^) per unit of length 

 is -388. By formula (13). — The work (u) expended in producing rupture 

 = 43758. 



Exp. XVIII.— Bar of Steel from Messrs. Naylor, Vickers & Co., Sheffield. 



Mark on bar " V.S." 



Before experiment. After experiment. 



Height of specimen -989 inch. .... -847 inch. 



Diameter of specimen -72 inch. .... -742 inch. 



Area of specimen -40715 sq. in -43241 sq. in. 



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

 or 100-7 tons ; and the corresponding compression {\) per unit of length 

 is -153. By formula (13). — The work (v) expended in producing rupture 

 = 17255. 



