The Bessemer Process for the Manufacture of Steel
Sir Henry Bessemer (19 January 1813 – 15 March 1898) was an English inventor, whose steelmaking process would become the most important technique for making steel in the nineteenth century for almost one century from year 1856 to 1950. He also played a significant role in establishing the town of Sheffield as a major industrial centre.
Bessemer had been trying to reduce the cost of steelmaking for military ordnance, and developed his system for blowing air through molten pig iron to remove the impurities. This made steel easier, quicker and cheaper to manufacture, and revolutionized structural engineering. One of the most significant innovators of the Second Industrial Revolution, Bessemer also made over 100 other inventions in the fields of iron, steel and glass. Unlike most inventors, he managed to bring his own projects to fruition and profited financially from their success.
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. As he relates in his autobiography, he examined the bronze powder made in Nuremberg which was the only place where it was made at the time. He then copied and improved the product and made it capable of being made on a simple production line.
It was an early example of reverse engineering where a product is analyzed, and then reconstituted. The process was kept secret, with only members of his immediate family having access to the factory. It was a widely used alternative to a patent, and such trade secrets are still used today. The Nuremberg powder, which was made by hand, retailed in London for £5 12s per pound and he eventually reduced the price to half a crown, or about 1/40th. The profits from sale of the paint allowed him to pursue his other inventions.
Bessemer patented a method for making a continuous ribbon of plate glass in 1848, but it was not commercially successful (see his autobiography, chapter 8). He gained experience in designing furnaces, which was to be of great use for his new steel-making process.
Bessemer licensed the patent for his process to five ironmasters, but from the outset, the companies had great difficulty producing good quality steel. 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 because the quantity of carbon was difficult to control. Robert Forester Mushet, had carried out thousands of experiments at Darkhill Ironworks, in the Forest of Dean, and had shown that the quantity of carbon could be controlled by removing almost all of it from the iron and then adding an exact amount of carbon and manganese, in the form of spiegeleisen. This improved the quality of the finished product and increased its malleability. When Bessemer tried to induce makers to take up his improved system, he met with general rebuffs and was eventually driven to undertake the exploitation of the process himself. He erected steelworks in Sheffield in a business partnership with others, such as W & J Galloway & Sons, and began to manufacture steel. 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 licenses 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.
However Mushet received nothing and by 1866 was destitute and in ill-health. 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. Bessemer decided to pay Mushet an annual pension of £300, a very considerable sum, which he paid for over 20 years; possibly with a view to keeping the Mushets from legal action.
W M Lord has said with regard to this success that “Sir Henry Bessemer was somewhat exceptional. He had developed his process from an idea to a practical reality in his own lifetime and he was sufficiently of a businessman to have profited by it. In so many cases, inventions were not developed quickly and the plums went to other persons than the inventors.