Chemistry and Physics. 



409 



converted into pure malleable iron, which he will form into ingots of any- 

 suitable size and shape by simply opening the tap-hole of the converting 

 . vessel and allowing the fluid malleable iron to flow into the iron ingot- 

 moulds placed there to receive it. The masses of iron thus formed will 

 be perfectly free from any admixture of cinder, oxyd or other extraneous 

 matters, and will be far more pure, and in a forwarder state of manufac- 

 ture than a pile formed by ordinary puddle bars. And thus it will be 

 seen that by a 'single process, requiring no manipulation or particular 

 skill, and with only one workman, from three to five tons of crude iron 

 passes into the condition of several piles of malleable iron in from thirty 

 to thirty-five minutes, with the expenditure of about one-third part the 

 blast now used in a finery furnace with an equal charge of iron, and with 

 the consumption of no other fuel than is contained in the crude iron. 



To those who are best acquainted with the nature of fluid iron it may 

 be a matter of surprise that a blast of cold air forced into melted crude 

 iron is capable of raising its temperature to such a degree as to retain it 

 in a perfect state of fluidity after it has lost all its carbon, and is in the 

 condition of malleable iron, which in the highest heat of our forges only 

 becomes softened into a pasty mass. But such is the excessive tempera- 

 ture that I am enabled to arrive at with a properly shaped converting 

 vessel and a judicious distribution of the blast, that I am able not only 

 to retain the fluidity of the metal, but to create so much surplus heat as 

 to re-melt the crop ends, ingot runners, and other scrap that is made 

 throughout the process, and thus bring them without the labor or fuel 

 into ingots of a quality equal to the rest of the charge of new metal. 

 For this purpose a small arched chamber is formed immediately over the 

 throat of the converting vessel, somewhat like the tunnel-head of the blast 

 furnace. This chamber has two or more openings on the sides of it, and 

 its floor is made to slope downwards to the throat. 



As soon as a charge of fluid malleable iron has been drawn off from 

 the connecting vessel, the workman will take the scrap intended to be 

 worked into the next charge and proceed to introduce the several pieces 

 into the small chamber, piling them up around the opening of the throat. 

 When this is done he will run in his charge of crude metal, and again 

 commence the process. By the time the boil commences the bar ends or 

 other scrap will have acquired a white heat, and by the time it is over 

 most of them will have been melted and run down into the charge. Any 

 pieces, however, that remain, may then be pushed in by the workman, 

 and by the time the process is completed they will all be melted, and ulti- 

 mately combined with the rest of the charge, so that all scrap-iron, 

 whether cast or malleable, may thus be used up without any loss or ex- 

 pense. 



As an example of the power that iron has of generating heat in this 

 process, I may mention a circumstance that occurred to me during my 

 experiments : I was trying how small a set of tuyeres could be used, but 

 the size chosen proved to be too small, and after blowing into the metal 

 for one hour and three-quarters I could not get up heat enough with them 

 to bring on the boil. The experiment was therefore discontinued, during 

 which time two-thirds of the metal solidified, and the rest was run oft". 

 A larger set of tuyere pipes were then put in, and a fresh charge of fluid 



SECOND SERIES, VOL. XXII, NO. 66. — NOV., 1856. 



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