1895.] Strains in the Testing of Materials and Structures. 137 



influence of overstrain and subsequent rest. It was made on a 

 turned bar of moderately hard, or semi-mild steel, which had not 

 been previously loaded beyond 6 tons. The diameter was 0*705 

 inch, and the section 0'390 sq. inch. The length under test was 

 9 inches. 



(4A.) Semi-mild Steel. Primitive state. 



Differences. 



Per half-ton. 



42 

 43 

 43 

 42 

 43 

 42 

 44 

 41 

 40 

 43 



45 



permanent extension 

 on the 9-inch 



The load was removed and the extensometer reset to 9 inches, 

 and the following test was immediately made, beginning 10 minutes 

 after the yielding took place : 



(4s.) Same piece, after stretching by a load of 11 tons. 



Difference per 

 Load in tons. Extensometer. half-ton. 



200 

 i 243 43 



1 287 44 

 331 44 



