124 



REPORT 1869. 



Exp. III. — Bar of Steel from the Barrow Hoematite Steel and Iron Com- 

 pany. Elongations taken on 8 inches length. Mark on bar, " H 3." 

 75 inch. Area -4417 square inch. 

 542 inch. Area -2306 square inch. 



Diameter of specimen 

 diameter after fracture 



Beduced 



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

 68,607 lbs., or 30-63 tons, and the corresponchng elongation (?j) per unit of 

 length is ^0656. By formula (13). — The work {u) expended in producing 

 rupture = 2250. 



Exp. rV. (January 1868). — Bar of Steel from the Barrow Hajmatite Steel 

 and Iron Company. Elongations taken on 8 inches length. Mark 

 on bar, " H I4-." Diameter of specimen -763 inch. Area "4572 square 

 inch. Reduced diameter after fracture -51 inch. Area '2043 square 

 inch. 



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

 66,281 lbs., or 29-59 tons, and the corresponding elongation (ZJ per imit of 

 length is -1858. By formula (13). — The work (it) expended in producing 

 nipture = 6157. 



