9 



been broken off in one or two years after they were laid down, 

 in consequence of their having been made of hot blast iron. 



There has, also, still more recently, been a series of 

 experiments made, upon which a far greater dependance may 

 be placed, inasmuch as the irons were all supplied in the 

 regular way of business, without the makers knowing any 

 such experiments were intended ; and they were undertaken 

 for the purpose of information only, to guide the founder and 

 engineer who conducted the operations at his own establish- 

 ment. The detail of these valuable trials by Mr. Todd, of 

 Leeds, formed a paper read before this Society when last it 

 met at Leeds. I need not, therefore, occupy your time with 

 repeating them here, and will only call your attention to a 

 few of the results, for the purpose of more clearly explaining 

 what I wish particularly to impress on your notice.* 



With respect to the strength of bar iron made from hot blast 

 pig iron, very few experiments have been made public that I 

 am aware of ; Mr. Todd's experiments are, therefore, of very 

 great importance, because they were made with the greatest 

 possible care, and regardless of expense, by manufacturers of 

 the first eminence and ability for their private information. 

 The irons were eight in number ; the first set of bars were 2i 

 inches in diameter, made with cold blast scraps and hot blast 



* They took place from August, 1840, to February, 1841. 



Breaking weight. 



Cicts. Qrs. 



Bierley pig iron, No. 3, made with cold blast, average 25 2 



Elsecar do No. 3, do. do. 24 0 



Low Moor do No. 3, do. do. 23 2 



Summerlee(Scotch)do.No. 3, hot blast, do. 17 2 



Level, Staffordshire do. No. 3, do. do. 16 0 



Mixed do No. 3, 5 parts Low Moor, ) 30 0 



• I part Elsecar ) 



Mixed do No. 3, 5 parts Bierley, ) , qq n 



1 part Elsecar \ '^'^ " 



Mixed do No. 3, equal parts Bierley, ^ 



Elsecar, Low Moor, Staffordshire, (Cylinder iron > do. 20 2 



in the market,) and Level iron, also Summerlee ) 



