90 



REPORT— 1853. 



Experiments to determine the resistance of Cast-iron bars obtained from 

 repeated Millings to a transverse strain. 



The fractured ends of these bars (when viewed with a microscope) are 

 remarkable for great uniformity of texture. In the Hrst melting they had 

 changed their appearance entirely from the pig in their crystalline structure, 

 the crystals being much more minute and of greatly increased density, 

 as may be seen on reference to the column of specific gravity below. 



Results reduced to those of bars 1*00 in. square. 



Experiment 1 , bar 4 ft. 6 in. between 

 sujiports 



Experiment 2, bar 4 ft. 6 in. between 

 supports 



Experiment 3, bar 4 ft. 6 in. between 

 supports 



Specific 

 gravity. 



6^969 



Mean. 



6-969 



Breaking 

 weight (6). 



Ultimate 

 deflection 



Product b X 



d, or power 



of resisting 



impact. 



463 

 536 

 470 



489-2 



1^27 

 154 

 151 



588 8 

 825^4 

 709-7 



705^6 



