100 



blast pig iron. The irons on which it had been tried were 

 eight in number, the first set of bars were 2^ in. in diameter, 

 made with cold blast scraps, and hot blast respectively, all 

 from Yorkshire manufacturers. The weight required to draw 

 them asunder by a steady direct tension was not very variable, 

 but when all were cut round to the same depth for the pur- 

 pose of being broken with the hammer, they required about 

 the following blows to do so. 



Cold blast bar iron six blows. 



Scrap ditto three blows. 



Hot blast ditto one blow. 



In the second and third set of bars, all of which were laid 

 before the meeting held at Wakefield, the result of the 

 experiments stood thus : — 



Blows required 



Diam. of bar. Area of sec. to break them 



in. where cut. with a 17 lbs. 



hammer. 



Low Moor cold blast . . . 2.66 ... 3.976 ... 18 



Bierley cold blast 2.75 ... 4.430 ... 18 



Milton hot blast 2.75 ... 4.430 ... 3 



Blows required 

 to break them 

 with a 20 lbs. 

 hammer. 



Elsecar cold blast 2.58 ... 3.976 ... 21 ~J 



Milton hot blast 2.58 ... 4.202 ... li > 



Made from the same materials. J 



So that the proportionate resistance of hot blast wrought 

 iron to impact is still less than that of cast iron. With 

 reference to the price of cold and hot blast iron, Mr. Hartop 

 produced the following table, — 



March, 1842. per ton. 



Price of Scotch hot blast iron at Hull, 



(No. 1.) £3 7 6 



To which add for its general inferiority to 

 Yorkshire iron when both were made with 

 cold blast 0 5 0 ^ 



I 



3 12 6 



