103 



Experhnents on two varieties of Iron. 



TABLE II. 



Experiments on the tenacity of Iron in specimen No. 2. 



The elongations observed after the first fracture on each bar, 

 were as follows : 



No. V, in an original length of 6 inches, had been elongated .9 inch. = 15 per ct, 

 ti yj^ li « 5 a u ,3 it ^ Q a 



tt VII, " " 5 " " .85 " =17 " 



li Yiii^ II ti 5 ti it .55 a ^ 11 it 



This variety of iron is thus seen to exhibit an extensibility by 

 this mode of trial, rather less than that of No. 1 ; the mean here 

 being for the four bars 12 J per ct., and for the four bars of No. 1, 

 13.6 per ct. But on comparing the total elongations of all the 

 bars after fracture, we find, 



From specimen No. 1. 



No. I, gave 35. per cent. "1 

 " II, " 20.5 " 1 mean 

 " III, " 28.9 " f27.2. 

 " IV, « 24.4 " J 



From specimen No. 2. 



No. V, gave 38.5 per cent."] 

 " VI, " 20. " I mean 



" VII, " 26. " [29.3. 



" VIII, " 32.9 « J 



