ON THE MECHANICAL PROPERTIES OF STEEL. 



129 



Exp. XIII. — Bar of Steel from the Heaton Steel and Iron Company, Laugley 

 MiUs. Elongations taken on 8 inches length. Mark on bar, " 4." 

 Diameter of specimen -746 inch. Area -4370 square inch. Re- 

 duced diameter after fracture -746 inch. Area -4370 square inch. 



Breaking-strain per 

 square inch of section. 



lbs. 



104869 



tons. 



46-816 



Per unit of length. 



Elongation. 



•0019 

 •0208 

 •0234 

 •0250 

 •0274 

 •0364 



Permanent 



set. 



Remarks. 



•0131 

 •0206 



•0312 



Broke in neck. 



Results. — Here the breaking-strain (P^) per square inch of section is 

 104,869 lbs., or 46-816 tons, and the corresponding elongation {l^ per unit 

 of length is -0364. By formula (13).^ — The work {u) expended in produ- 

 cing rupture = 1908. 



Exp. XIV. — Bar of Steel from the Heaton Steel and Iron Company, Langley 

 Mills. Elongations taken on 8 inches length. Mark on bar, " 5." 

 Diameter of specimen -754 inch. Area -4465 square inch. Reduced 

 diameter after fracture -754 inch. Area -4465 square inch. 



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

 98,866 lbs., or 44-136 tons, and the corresponding elongation (l^ per unit of 

 length is -0937. By formula (13). — The work (m) expended in producing 

 rupture = 4631. 



1869. 



