Sir Henry Bessemer FRS (19 January 1813 – 15 March 1898) was an English inventor, whose steel-making process would become the most important technique for making steel in the nineteenth century for almost one hundred years.

[4][5] Bessemer had been trying to reduce the cost of steel-making for military ordnance, and developed his system for blowing air through molten pig iron to remove the impurities.

There he invented a process for making gold chains, which was successful, and enabled him to buy a small estate in the village of Charlton, near Hitchin in Hertfordshire, where Henry was born.

[10][11] The invention from which Bessemer made his first fortune was a series of six steam-powered machines for making bronze powder, used in the manufacture of gold paint.

[15] On 24 August 1856 Bessemer first described the process to a meeting of the British Association in Cheltenham which he titled "The Manufacture of Malleable Iron and Steel without Fuel."

The Bessemer process involved using oxygen in air blown through molten pig iron to burn off the impurities and thus create steel.

Examples include railway structures such as bridges and tracks, where the treacherous nature of cast iron was keenly felt by many engineers and designers.

[19] Mr Göran Fredrik Göransson, a Swedish ironmaster, using the purer charcoal pig iron of that country, was the first to make good steel by the process, but only after many attempts.

His results prompted Bessemer to try a purer iron obtained from Cumberland hematite, but even with this he had only limited success[18] because the quantity of carbon was difficult to control.

At first the output was insignificant, but gradually the magnitude of the operations was enlarged until the competition became effective, and steel traders generally became aware that the firm of Henry Bessemer & Co. was underselling them to the extent of UK£10–£15 a ton.

This argument to the pocket quickly had its effect, and licences were applied for in such numbers that, in royalties for the use of his process, Bessemer received a sum in all considerably exceeding a million pounds sterling.

In that year his 16-year-old daughter, Mary, travelled to London alone, to confront Bessemer at his offices, arguing that his success was based on the results of her father's work.

The mechanism – hydraulics controlled by a steersman watching a spirit level – worked in model form and in a trial version built in his garden in Denmark Hill, London.

IOM3 still recognises Bessemer's legacy with an annual award of the medal for outstanding services to the steel industry; recent recipients include Indira Samarasekera.

That a man who did so much for industrial development did not receive higher recognition from his own government was a source of deep regret for English engineers, who alluded to the fact that in the United States, where the Bessemer process found much use, eight cities or towns bore his name.