IRON AND STEEL. 67 



earlier by Dud Dudluy, a cousin I believe of the unfortunate husband 

 of Lady Jane Grey, but though he demonstrated the practicability of 

 it, he achieved for himself only ridicule, disappointment and great 

 pecuniary loss. Revived in 1735 by Abraham Darby at Coalbrook- 

 dale in Shropshire, it proved immediately successful, and restored to 

 Britain her iron industry, which had fallen into a great decline 

 through want of fuel. The first iron cylinders for supplying a blast 

 to the furnace were constructed by John Smeaton at the Carron Iron 

 Works in Scotland, and steam was first used at the same works to 

 furnish the power through the influence of of Dr. Roebuck. 



Since then the only important improvements introduced in the 

 productive iron industry have been the application of the hot blast, 

 first employed by Neilson in Scotland in 1728, and the withdrawal 

 of unconsumed gases from the top of the furnace, and their utilization 

 for the production of heat. 1 think France is entitled to credit for 

 that discovery. 



Iron is of two kinds — -cast iron, containing from 3 to 5 per cent 

 of carbon, which is brittle and granular in its construction ; and mal- 

 leable or wrought iron, which is ductile and fibrous, and contains 

 little or no carbon. Between the two lies steel, containing from a 

 quarter of 1 percent to 2 per cent of carbon. If you ask me for a 

 technical definition of the word steel, I shall tell you frankly that I 

 cannot give it, and I have heard some very expert metallurgists express 

 dislike to be put to the same test. A few years ago you would be 

 told off hand that steel was an article which would forge, temper and 

 weld; but if you demand these qualities to-day you will relegate to 

 the iron heap a great many articles which the world calls steel, in- 

 cluding all metal produced by the pneumatic process. I believe the 

 article produced in the Bessemer converter, however, to be a true 

 steel, but it will not weld.* 



In former times steel was sometimes obtained as part of the 

 product of the bloomary united in certain proportions with soft iron 

 in the bloom or loop. But when it was desired to produce steel 

 from iron, very fine bar iron was arranged in layers in a fire-brick 

 oven, each layer of iron being overlaid with charcoal. All openings 

 were then carefully closed with clay and the whole oven was heated 

 to redness and kept at that temperature for from seven to ten days. 



* Since this paper was read I have learned that improvements in the pneumatic process have 

 resulted in producing steel that will weld, and that Bessemer steel is daily being applied to new 

 uses. 



