138 THE ADDRESSES, LECTURES, ETC., OF 



attain its highest qualities both as regards power of resistance and 

 ductility. 



Iron and Steel were known to the ancients, and are referred to 

 in their writings, but we have no account of the processes 

 employed in the manufacture of these metals until comparatively 

 speaking recent times. Aristotle describes steel as purified iron, 

 and says that it is obtained by remelting iron several times, and 

 treating it with various fluxes ; we are hence led to suppose that 

 in Aristotle's time steel was made by careful selection, and treat- 

 ment of steely iron, which latter was produced by something 

 analogous to the Catalan process. 



A method referred to by ancient authors, is to bury iron in 

 damp ground for some time, and then to heat and hammer it. 

 Another process first described in Biringuccio's " Pyrotechnology," 

 one of the earliest works on Metallurgy, and later in Agricola's 

 " De Ee Metallica," both published in the 16th century, is to re- 

 tain malleable iron for some hours in a bath of fused cast iron, 

 when it becomes converted into steel. Reaumur, in 1722, pro- 

 duced steel by melting three parts of cast iron with one part of 

 wrought iron (probably in a small crucible) in a common forge, 

 but he failed to produce steel in this manner upon a working 

 scale. 



A similar method of producing steel to that proposed by 

 Reaumur has been employed in India for ages, the celebrated 

 Wootz steel being the result of partial or entire fusion of steely 

 iron and carbonaceous matter, in small crucibles arranged in a 

 primitive air furnace, followed by a lengthy exposure of the ingots 

 to heated air in order to effect a partial decarburization. 



In 1750, Hasenfratz refers, in his " Siderotechnic," to three 

 processes for producing steel ; melting broken fragments of steel 

 with suitable fluxes, fusing malleable iron with carbonaceous matter 

 and so treating cast iron (probably with oxides) as to obtain cast 

 steel directly from it. 



The credit of producing cast steel upon a working scale is due 

 to Huntsman, who was the first to accomplish its entire fusion in 

 crucibles, placed amongst the coke of an air furnace, which fluid 

 metal he poured into metallic moulds. This process is still carried 

 on largely at Sheffield for the production of special qualities of 

 steel, such as tool steel, tyre steel, castings and forgiugs, and a ton 



