ON THE MECHANICAL PROPERTIES OF STEEL. 107 



FIRST SERIES OF EXPERIMENTS. 



TRANSVERSE STRAIN. 



Experiment I, (June 1867). — Bar of Steel from the Barrow Haematite Steel 

 Company. Dimension of bar 1-02 inch square. Length between 

 supports 4 feet 6 inches. Mark on bar, " H 1. Hard Steel." 



Besults of Exp. I. 



Here the weight {lu) at the limit of elasticity is 1210 lbs., and the corre- 

 sponding deflection (S) is 1*546. 



By formula (6). — The mean value of the deflection for unity of pressure 

 and section (Dj) =-001308. 



By formula (7). — The mean value of the modulus of elasticity (E) 

 = 30,096,000. 



By formula (2). — The modulus of elasticity (E) corresponding to 112 lbs. 

 pressure =33,830,000. 



By formula (8). — ^Work of deflection (U) up to the limit of elasticity 

 = 77-944. 



By formula (9). — Work of deflection (m) for unity of section = 77-917. 



By formula (12). — Yalue of C, the unit of working strength = 6-860 tons. 



