ON THE CONSTRUCTION OF HOOPED CANNON 



51 



Fig. 1. Wire, hard, as it came from the draw-plate; 140 

 Area, .006789 square inches. 



foW^s 



Fig. 2. Same Wire, after the above strain. 



Fig. 3. Same Wire, after being heated, when under a strain of 40 pounds, so 

 it, through its whole length. Temperature estimated at 850° . 



as to burn oil upon 



520 



Went down 

 slowly 



for six hours 



The 



wire being 140 inches 



Weight reduced to 600 



Wire broke, 510 



With the lo *d of 280 pounds 



14,000 hundredths of an inch, we have the first permanent elongation 



of the length. 



41,241 pounds per square inch section; and this elongation is only x^i^o"^ 1 



° f the length of the rod. 



With the same strain the permanent elasticity is -^ths of an inch, or T ^ \^ths 



vhvfl 



