95 



Experiment Qth. — ^The sama bar, after receiving the above 26 

 blows in Experiment 5, was nicked as in Experiment 4 : 



2 blows fractured it. ) Fracture | fine fibrous iron. 

 4 more broke it off". / | crystalized. 



Experiment 7th. — Hot blast bar from Milton Iron Works, 2i 

 inches diameter ; heated red and hammered till cold, reduced in 

 hammering of an inch, laid 4 inches over the anvil ; 50 blows 

 bent it inches. It was then nicked on the outside J of an inch 

 deep, and 1^ inches round; 31 more blows produced a slight 

 fracture of the fine&'t and toughest character. 



Experiment 8th. — Cold blast cable bar from Messrs. Hawthorn's 

 stock ; cold hammered, reduced 2| inches diameter, laid 4 inches 

 over the anvil, as above; 50 blows bent it about 1^ inches, no 

 fracture. It was then nicked as in Experiment 7 ; 2 blows broke 

 it square across, fracture quite crystalized. 



Note. — The hammer used in these experiments weighed 31 lbs. 



Copy of Letter from Messrs. R. and W. Hawthorn, to 

 Graham and Co., dated December 8th, 1842 : — 



Gentlemen, — Our experiments on wrought iron already handed 

 you, so far as related to your make, were exclusively confined to 

 hot blast iron, but we have since added a few experiments on your 

 make of cold blast iron, which we beg to hand you as follows^ viz : 



Experiment 1st — Cold blast iron from Milton Iron Works, 

 marked " C.B. Plate," bar If inches square, heated red and ham- 

 mered till nearly cold, reduced to 1^ inches, laid 4 inches over the 

 anvil. 



9 blows slightly bent it, "i Fracture close crystalized, 

 the 10th blow broke it clean off. j resembling steel. . 

 Experiment 2nd. — -A bar of cold blast iron from Milton Iron 

 Works, 2^ inches diameter, laid 4 inches over the anvil. 

 I 1 0 blows bent it of an inch "j r^-^^^^ 

 I 10 „ more „ {'^ „ ' "^"^ 

 in 10 



I JJ J> ?> 5? 



\ iJ J) 11a '> 



in 14 



j J) >? >5 " 



i No appearance of fracture. It was then nicked on the outside as 

 at a an |- of an inch deep, and 1 J inches round. 



2 blows fractured J of the section, | Fracture crystal- 

 the 3rd blow broke it clean off. / ized. 



Note — ^The hammer used in these two experiments weighed 30 lbs. 



