ON THE MECHANICAL PROPERTIES OF STEEL. 



247 



THIRD SERIES OF EXPERIMENTS. 



COMPEESSION. 



Exp. I. — Bar of St6el from Messrs, John Brown & Co., Sheffield. Mark on 



bar, " B 1.' 



Before experiment. 



Height of specimen 1-004 inch. 



Diameter of specimen "72 inch. 



Ai-ea of specimen -40715 sq. in. 



After experiment. 

 •755 inch. 

 •774 inch. 

 •47015 sq. in. 



No. 



of 



Exp. 



Weight laid 



on 



specimen. 



Weight laid 



on per square inch 



of section. 



Compres- 

 sion, in 

 inches. 



Remarks. 



lbs. 

 37438 

 44966 

 52166 



58950 

 66022 

 73134 

 80214 

 88134 

 91840 



tons. 



16-731 

 20-074 

 23-288 

 26-316 

 29-474 

 32-649 

 35-809 

 39-345 

 41-000 



lbs. 



91951 

 110440 

 128124 

 144786 

 162156 

 179772 

 197023 

 216465 

 225568 



tons. 



41-049 

 49-303 

 57-198 

 64-637 

 72-391 

 80-233 

 87-952 

 96-636 

 100-700 



-020 

 -025 

 -043 

 -049 

 -078 

 •117 

 •166 

 •225 

 •253 



One 



very 



crack appeared. 



Results. — Here the strain per square inch (PJ causing rupture is 225,568 

 lbs., or 100-7 tons ; and the corresponding compression (f^) per unit of length 

 is -253. By formula (13). — The work (tt) expended in producing rupture 

 = 28533. 



Exp. II. — Bar of Steel from Messrs. John Brown & Co., Sheffield. Mark on 



bar, " B 2." 



Before experiment. 



Height of specimen -980 inch. 



Diameter of specimen .... -72 inch. 

 Area of specimen ^40715 sq. in. 



After experiment. 

 •724 inch. 

 •785 inch. 

 •48398 sq. in. 



37438 

 44966 

 52166 

 58950 

 66022 

 73134 

 80214 

 88134 

 91840 



16-731 



20-074 

 23-288 

 26-316 

 29-474 

 32-649 

 35-809 

 39-345 

 41-000 



91951 

 110440 

 128124 

 144786 

 162156 

 179772 

 197023 

 216465 

 225568 



41-049 

 49-303 



57-198 

 64-637 

 72-391 

 80-233 

 87-952 

 96-636 

 100-700 



020 

 025 

 043 

 069 

 088 

 147 

 196 

 265 

 263 



No cracks. 



Results. — Here the strain per square inch (PJ causing rupture is 225,568 

 lbs., or 100-7 tons ; and the corresponding compression (ZJ per unit of length 

 is -263. By formula (13).— The work (y) expended in producing rupture 



