An Autobiography [168]
invention. If I remember rightly, you held up a piece of my malleable iron, saying words to this effect: 'Here is a true British nugget! Here is a new process that promises to put an end to all puddling; and I may mention that at this moment there are puddling furnaces in successful operation where my patent hollow steam Rabbler is at work, producing iron of superior quality by the introduction of jets of steam in the puddling process. I do not, however, lay any claim to this invention of Mr. Bessemer; but I may fairly be entitled to say that I have advanced along the road on which he has travelled so many miles, and has effected such unexpected results that I do not hesitate to say that I may go home from this meeting and tear up my patent, for my process of puddling is assuredly superseded.'"
After giving an account of the true origin of his process, in which he had met with failures as well as successes, but at last recognised the decarburation of pig iron by atmospheric air, Sir Henry proceeds to say:
"I prepared to try another experiment, in a crucible having no hole the the bottom, but which was provided with an iron pipe put through a hole in the cover, and passing down nearly to the bottom of the crucible. The small lumps and grains of iron were packed around fit, so as nearly to fill the crucible. A blast of air was to be forced down the pipe so as to rise up among the pieces of granular iron and partially decarburise them. The pipe could then be withdrawn, and the fire urged until the metal with its coat of oxyde was fused, and cast steel thereby produced.
"While the blowing apparatus for this experiment was being fitted up, I was taken with one of those short but painful illnesses to which I was subject at that time. I was confined to my bed, and it was then that my mind, dwelling for hours together on the experiment about to be made, suggested that instead of trying to decarburise the granulated metal by forcing the air down the vertical pipe among the pieces of iron, the air would act much more energetically and more rapidly if I first melted the iron in the crucible, and forced the air down the pipe below the surface of the fluid metal, and thus burn out the carbon and silicum which it contained.
"This appeared so feasible, and in every way so great an improvement, that the experiment on the granular pieces was at once abandoned, and, as soon as I was well enough, I proceeded to try the experiment of forcing the air under the fluid metal. The result was marvellous. Complete decarburation was effected in half an hour. The heat produced was immense, but, unfortunately more than half the metal was blown out of the pot. This led to the use of pots with large hollow perforated covers, which effectually prevented the loss of metal. These experiments continued from January to October 1855. I have by me on the mantelpiece at this moment, a small piece of rolled bar iron which was rolled at Woolwich arsenal, and exhibited a year later at Cheltenham.
"I then applied for a patent, but before preparing my provisional specification (dated October 17, 1855), I searched for other patents to ascertain whether anything of the sort had been done before. I then found your patent for puddling with the steam rabble, and also Martin's patent for the use of steam in gutters while molten iron was being conveyed from the blast furnace to a finery, there to be refined in the ordinary way prior to puddling.
"I then tried steam in my cast steel process, alone, and also mixed with air. I found that it cooled the metal very much, and of itself could not be used, as it always produced solidification. I was nevertheless advised to claim the use of steam as well as air in my particular process (lest it might be used against me), at the same time disclaiming its employment for any purpose except in the production of fluid malleable iron or steel. And I have no doubt it is to this fact that I referred when speaking to you on the occasion you mention. I have deemed it best that the exact truth--so far as a short
After giving an account of the true origin of his process, in which he had met with failures as well as successes, but at last recognised the decarburation of pig iron by atmospheric air, Sir Henry proceeds to say:
"I prepared to try another experiment, in a crucible having no hole the the bottom, but which was provided with an iron pipe put through a hole in the cover, and passing down nearly to the bottom of the crucible. The small lumps and grains of iron were packed around fit, so as nearly to fill the crucible. A blast of air was to be forced down the pipe so as to rise up among the pieces of granular iron and partially decarburise them. The pipe could then be withdrawn, and the fire urged until the metal with its coat of oxyde was fused, and cast steel thereby produced.
"While the blowing apparatus for this experiment was being fitted up, I was taken with one of those short but painful illnesses to which I was subject at that time. I was confined to my bed, and it was then that my mind, dwelling for hours together on the experiment about to be made, suggested that instead of trying to decarburise the granulated metal by forcing the air down the vertical pipe among the pieces of iron, the air would act much more energetically and more rapidly if I first melted the iron in the crucible, and forced the air down the pipe below the surface of the fluid metal, and thus burn out the carbon and silicum which it contained.
"This appeared so feasible, and in every way so great an improvement, that the experiment on the granular pieces was at once abandoned, and, as soon as I was well enough, I proceeded to try the experiment of forcing the air under the fluid metal. The result was marvellous. Complete decarburation was effected in half an hour. The heat produced was immense, but, unfortunately more than half the metal was blown out of the pot. This led to the use of pots with large hollow perforated covers, which effectually prevented the loss of metal. These experiments continued from January to October 1855. I have by me on the mantelpiece at this moment, a small piece of rolled bar iron which was rolled at Woolwich arsenal, and exhibited a year later at Cheltenham.
"I then applied for a patent, but before preparing my provisional specification (dated October 17, 1855), I searched for other patents to ascertain whether anything of the sort had been done before. I then found your patent for puddling with the steam rabble, and also Martin's patent for the use of steam in gutters while molten iron was being conveyed from the blast furnace to a finery, there to be refined in the ordinary way prior to puddling.
"I then tried steam in my cast steel process, alone, and also mixed with air. I found that it cooled the metal very much, and of itself could not be used, as it always produced solidification. I was nevertheless advised to claim the use of steam as well as air in my particular process (lest it might be used against me), at the same time disclaiming its employment for any purpose except in the production of fluid malleable iron or steel. And I have no doubt it is to this fact that I referred when speaking to you on the occasion you mention. I have deemed it best that the exact truth--so far as a short