Sir Henry Bessemer (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 from 1856 to 1956. He also played a significant role in establishing the town of Sheffield, nicknamed ‘Steel City’, as a major industrial centre.
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. This made steel easier, quicker and cheaper to manufacture, and revolutionised structural engineering. One of the most significant inventors of the Second Industrial Revolution, Bessemer also made over 100 other inventions in the fields of iron, steel and glass. Unlike many inventors, he managed to bring his own projects to fruition and profited financially from their success. He was knighted for his contribution to science in 1879, and in the same year was made a fellow of the Royal Society.
Father: Anthony Bessemer
Bessemer's father, Anthony, was born in London into a Huguenot family, but moved to Paris when he was about 21 years old. He was an inventor who, while engaged by the Paris Mint, made a machine for making medallions that could produce steel dies from a larger model. He became a member of the French Academy of Science, for his improvements to the optical microscope when he was 26. He was forced to leave Paris by the French Revolution, and returned to Britain. 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. According to Bessemer he was given his name by his godfather Henry Caslon, who employed his father as a punchcutter.
Early inventions
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 analysed, and then reproduced.
The process was kept secret, with only members of his immediate family having access to the factory. 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 process
Henry Bessemer worked on the problem of manufacturing cheap steel for ordnance production from 1850 to 1855 when he patented his method.
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." It was published in full in The Times. The Bessemer process involved using oxygen in air blown through molten pig iron to burn off the impurities and thus create steel. James Nasmyth had been working on a similar idea for some time prior to this. A reluctant patentor, and in this instance still working through some problems in his method, Nasmyth abandoned the project after hearing Bessemer at the meeting. Bessemer acknowledged the efforts of Nasmyth by offering him a one-third share of the value of his patent. Nasmyth turned it down as he was about to retire.
Many industries were constrained by the lack of steel, being reliant on cast iron and wrought iron alone. Examples include railway structures such as bridges and tracks, where the treacherous nature of cast iron was keenly felt by many engineers and designers. There had been many accidents when cast iron beams collapsed suddenly, such as the Dee Bridge disaster of May 1847, the Wootton bridge collapse and the Bull bridge accident of 1860. The problem recurred at the Tay Bridge disaster of 1879, and failures continued until all cast iron under-bridges were replaced by steel structures. Wrought iron structures were much more reliable with very few failures.