Henry Bessemer

Henry Bessemer, the son of an engineer and typefounder, had early shown considerable mechanical skill and inventive powers.

After the invention of movable stamps for dating deeds and other government documents and the improvement of a typesetting machine, he had gone to the manufacture of “gold” powder from brass for use in paints.

The florid decoration of the time demands great quantities of such material, and Bessemer's secret process had soon brought him great wealth.

He has developed other inventions, notably sugarcane-crushing machinery of advanced design, but he is soon devoted to metallurgy.

Henry Bessemer invents an elongated artillery shell that is rotated by the powder gases.

The French authorities with whom he is negotiating, however, point out that their cast-iron cannon would not be strong enough for this kind of shell.

He thereupon attempts to produce a stronger cast iron.

In his experiments he discovers that the excess oxygen in the hot gases of his furnace appears to have removed the carbon from the iron pigs that were being preheated—much as the carbon is removed in a puddling furnace—leaving a skin of pure iron.

Bessemer next finds that blowing air through melted cast iron not only purifies the iron but also heats it further, allowing the purified iron to be easily poured.

This heating effect is caused by the reaction of oxygen with the carbon and silicon in the iron.

Henry Bessemer, utilizing his new techniques, which later will become known collectively as the Bessemer process, is soon able to produce large, slag-free ingots as workable as any wrought-iron bloom, and far larger; he invents the tilting converter into which molten pig iron could be poured before air is blown in from below.

Eventually, with the aid of an iron-manganese alloy, which is developed at this time by Robert Forester Mushet, Bessemer also finds how to remove excess oxygen from the decarburized iron.

Henry Bessemer files his patent in the United Kingdom, for the Bessemer process of steelmaking, on     October 17, 1855.

Henry Bessemer’s announcement of his eponymous steelmaking process in 1856 before the British Association for the Advancement of Science in Cheltenham, Gloucestershire, brings many ironmasters to his door, and many licenses are granted.

Peter Cooper had erected a rolling mill and an iron mill in New York City, where he was the first to successfully use anthracite coal to puddle iron.

In 1845, he moved his machinery to Trenton, New Jersey, where he built the largest rolling-mill in the United States for producing railroad iron.

Here, in 1854, he had overseen the production of the first structural wrought iron beams.

Cooper introduces the Bessemer process to American steelmaking in 1856.