130 Prof. J. A. Ewing. On Measurements of small [May 16, 



Each ton corresponds in this case to a stress of 0'817 ton per 

 square inch. Taking the whole extension due to 20 tons to be 491, 

 or O00982 inch, Young's modulus is 



8x20x0-817 

 0-00982 



= 13310 tons per sq. inch. 



(2.) Turned bar of tool steel. Diameter, 0*706 inch. Length 

 under measurement, 9 inches. Temperature, 57 F. The bar had 

 not been previously loaded beyond 6 tons. 



Differences. 



Load in Extensometer , * ^ 



tons. readings. Per ton. Per half-ton. 



100 



1 184 84 



2 268 84 



3 352 84 



4 437 85 



5 522 85 



6 606 85 

 6^ 649 



691 

 733 

 776 

 819 



862 



904 



947 



990 



1032 



1075 



85 



85 



86 



85 



85 



43 

 42 

 42 

 43 

 43 

 43 

 42 

 43 

 43 

 42 

 43 



