Henry Bessemer – a London exhibition

Materials World magazine
10 May 2019

Visitors to 297 Euston Road, London, have the chance to view a small exhibition related to Sir Henry Bessemer – engineer, inventor and entrepreneur – in 2019.

While inventors such as James Dyson capture the public imagination today, in the Victorian Era Bessemer was the man to know. Actively involved in The Iron and Steel Institute - a forerunner of IOM3 - Bessemer’s name became synonymous with his steelmaking process.

Born in Charlton, Hertfordshire, UK, in 1813, Henry was the son of successful inventor and metallurgist, Anthony Bessemer. You could say metals were in his genes as his father taught young Bessemer to create alloys, knowledge that would help develop his steel success. An exhibition photograph shows four generations of the Bessemer family.

While we celebrate his steelmaking process, another material first took Bessemer’s interest – bronze powder. The powder was in demand for making gold-look paint, however it was only produced in Nuremberg, Germany, and was expensive. Bessemer developed a steam-driven machine for making the powder, and a small fortune in the process.

Wars drive ingenuity

Inevitably, the Crimean War of the 1850s brought changes to the UK. While Florence Nightingale was working to save lives with improved hygiene, Bessemer was working to upgrade artillery.

The exhibition contains an engraving of his system for firing elongated projectiles from a smoothbore gun. The guns of cast iron would often fail despite stronger shells, and Bessemer was also focused on advancing the metals used.

At the time, steel seemed the obvious choice to replace cast iron but it was hard to produce, needing high temperatures and lots of fuel. Bessemer tried many experiments, eventually realising that pushing oxygen through molten iron would make steel.

The principles of the process were not understood at the time, but Bessemer realised that the blast of compressed air burned out impurities in the liquefied iron. As he refined the process, Bessemer found that his steel was easier to shape than traditionally made metals, and that he could speedily produce greater quantities.

On 14 August 1856, Bessemer reported his process to the British Association for the Advancement of Science in a paper titled On the manufacture of malleable iron and steel without fuel. It was not all plain sailing for Bessemer - other foundries initially failed to replicate his results and Bessemer discovered iron with high phosphorus content was not suitable for the initial process. Because Bessemer was unable to persuade existing companies to use his method, he and his partners built their own iron works in Sheffield, UK, where phosphorus-free ore was easily found.

Eventually, other metallurgists solved the impurity issue, by adding manganese or spiegeleisen to the process, and Bessemer’s patented method began to take off in the UK and abroad. One of his patents, No. 1981, is on view outside the Bessemer room at 297 Euston Road. The Dowlais plant in Ebbw Vale had the first UK licence but the technology was adopted internationally, and a watercolour shows the first Swedish Bessemer Plant at Edske.

There is also a photograph of Workington Iron Company which under British Steel produced the last Bessemer Steel made in the UK in 1974. Ever since the Bessemer process patent was awarded, the process had been improved and seen competition but changes to the UK steel industry finally ended use here.

Recognition and reward

As well as being financially rewarded for his work, Bessemer collected a number of awards, some shown in the exhibition. These include the Prince Albert Gold Medal awarded by the Council of the Society of Arts in 1872, and the Howard Quinquennial Prize for 1877, awarded by the Institution of Civil Engineers to Bessemer as ‘the originator of the greatest improvement in the Iron Manufacture of Great Britain during the preceding five years’.

In 1880, the year after receiving his knighthood and being elected as a Fellow of the Royal Society, Bessemer was presented with the freedom of the City of London in an elaborate gold casket. The scroll and casket are on view, with the casket illustrating the process of steel making from the conversion of the raw material to application.

The receipt of awards must have given Bessemer satisfaction as he had previously experimented with the electrodeposition of copper on Napoleon medals and had established the Bessemer Gold Medal in 1873, to be given annually by the Iron and Steel Institute for the most important improvement in iron and steel manufacture during the year. IOM3 still awards this medal - prototypes and final versions are on display.

Other inventions - some successful, some not - personal items and metallurgical samples are also on view, including an image of the Bessemer Solitaire Diamond Ring.

In later life, Bessemer designed the machinery for cutting and polishing diamonds, which was installed in a factory in Clerkenwell where he established one of his grandsons in business. The solitaire diamond in the gold ring was the first diamond cut by Sir Henry Bessemer, it was presented to the wife of the then Secretary of the Iron and Steel Institute, Mr J Stephen Jeans.