Page:Dictionary of National Biography. Sup. Vol I (1901).djvu/250

 was admitted through the tuyeres into the charge for about ten minutes, when a violent explosion of sparks and flame and melted slag occurred, lasting some minutes. As soon as this had subsided the charge was tapped from the converter, and the metal was found to be wholly decarbonised malleable iron. After many experiments the fixed converter was replaced by one mounted on trunnions ; in its earliest form this arrangement was patented in February 1856.

The success of Bessemer's experiments attracted considerable attention, and this was increased to widespread enthusiasm on the reading of his famous paper before the British Association at the Cheltenham meeting in 1856. This paper was entitled 'On the Manufacture of Malleable Iron and Steel without Fuel.' The result of the paper was remarkable. Bessemer's reputation as a practical man of science was such that the statements he made were accepted without question, and within a month of the date of the meeting he had received no less than 27,000l. from ironmakers in different parts of the country for licenses to use the invention. But Bessemer's victory was not yet quite decisive. Trials of the process were hastily made by the licensees, without due care and knowledge, resulting for the most part in failure. Enthusiasm gave place to discredit, condemnation, and abuse, and for a while Bessemer's reputation and the Bessemer process were in danger of extinction. The great inventor, however, was not easily discouraged ; he carried out new experiments at Baxter House, spent thousands of pounds in the construction of fresh plant, and in 1858 he was able to show his numerous licensees why they had failed, and how they could make higher-class steel with certainty. Thus he justified the claims made in his Cheltenham paper of 1856, and proved that he had passed the experimental stage of manufacture. Then followed a violent opposition on the part of the steel trade, which was met by Bessemer erecting in 1859 his own works in Sheffield, and starting in business as a steel maker. Those works became financially successful ten years after they were opened, and have continued to flourish till the present time. In June 1859 Bessemer was selling tool steel (for the first time quoted on the metal market), the price being 21. 4s. per cwt. But this steel was not made by the real Bessemer process. The melted iron, having been quite decarbonised by the air blast, was granulated by being run into water, and was then remelted in a crucible with sufficient manganese to return the desired amount of carbon. It was in June 1859, however, that the first Bessemer steel was run direct from the converter, the decarbonising agent having been put into the charge after the blast had done its work. From this time the manufacture proceeded steadily on a constantly increasing scale. Subsequently, in 1879, the Bessemer process reached its ultimate stage of perfection, owing to the discovery by Sidney Gilchrist Thomas [q. v.] of a means of eliminating phosphorus in the Bessemer converter, and the manufacture of Bessemer steel was thereby greatly facilitated and cheapened in both England and America. The Bessemer process from 1865 onwards experienced the competition of the Siemens process for making steel ; this process was largely employed in Great Britain after its invention in that year [see Siemens, Sir William], but Bessemer's earlier invention has conspicuously maintained its superiority of output for the whole world.

A claim was made by Robert Forester Mushet [q. v.] to have anticipated Bessemer's invention altogether, and to have been the first to carry it to a successful issue. But there is no doubt that Bessemer worked independently of Mushet, and was not acquainted with Mushet's experiments till he had completed his own. He consented to the award of the Bessemer medal of the Iron and Steel Institute to Mushet in 1896, and bestowed on him an annuity of 300l. Mushet stated his case in 1883 in 'The Bessemer-Mushet Process, or the Manufacture of Cheap Steel.' Bessemer told his story in an unpublished autobiography.

Within five years of 1859, the date of the completion of Bessemer's invention, the Bessemer process had been adopted by all the steel-making countries of the world, and its real value was understood, though no one Avould have ventured to prophesy the vast developments that were in store for it. Reverting to the cause which had first led him to this line of investigation, Bessemer soon after 1859 made a speciality of gun-making at Sheffield, and manufactured some hundreds of weapons for foreign governments. No doubt indeed exists that, but for the opposition to the use of steel for ordnance in this country, that material would have been used in the British services twenty years sooner than was the case. The Bessemer steel exhibits at the London International Exhibition of 1862 gave a good idea of the state of the manufacture at the Sheffield works at that date. These exhibits included locomotive boiler tube plates, from one of which a disc 23 in. diameter and ¾ in. thick had been cut, and stamped into a cup 11 in.