tuyères. Under this tile was an air-chamber, connected by pipes with the blowing-engine. This is substantially the plan now used in the Bessemer converter. The first trial of this furnace was very satisfactory. The iron was well refined and decarbonized—at least as well as by the finery fire. This fact was admitted by all the forgemen who examined it. The blowing was usually continued from five to ten minutes, whereas the finery fire required over an hour. Here was a great saving of time and fuel, as well as great encouragement to work the process out to perfection. I was not satisfied with making refined or run-out metal; my object was to make malleable iron. In attempting this I made, in the course of the following eighteen months, a variety of experiments. I built a suitable hot-blast oven; but, after a few trials, abandoned it, finding the cold blast preferable, for many reasons. After many trials of this furnace I found that I could make refined metal, suitable for the charcoal forge fire, without any difficulty, and, when the blast was continued for a longer period, the iron would occasionally be somewhat malleable. At one time, on trying the iron, to my great surprise, I found the iron would forge well, and it was pronounced as good as any charcoal forge iron. I had a piece of this iron forged into a bar four feet long and three eighths of an inch square. I kept this bar for exhibition, and was frequently asked for a small piece, which I readily gave, until it was reduced to a length of a few inches. This piece I have still in my possession. It is the first piece of malleable iron or steel ever made by the pneumatic process."
Although not giving up the idea of making malleable iron, Mr. Kelly now proceeded to utilize his invention so far as it was a complete success. He built a converter, five feet high and eighteen inches inside diameter, with the tuyère in the side. In this vessel he could refine fifteen hundred-weight of metal in from five to ten minutes, effecting a great saving in time and fuel. After a few days' trial, the old, troublesome "run-out" fires were entirely dispensed with. "My process," says Mr. Kelly, in the account above quoted, "was known to every iron-maker in the Cumberland River iron district as 'Kelly's air-boiling process.' The reason why I did not apply for a patent for it sooner than I did was that I flattered myself I would soon make it the successful process I at first endeavored to achieve—namely", a process for making malleable iron and steel. In 1857 I applied for a patent, as soon as I heard that other men were following the same line of experiments in England; and, although Mr. Bessemer was a few days before me in obtaining a patent, I was granted an interference, and the case was heard by the Commissioner of Patents, who decided that I was the first inventor of this process, now
