Sidney Gilchrist Thomas was always interested in science. Originally destined to be a doctor, after his father’s death he changed his plans. He became a police clerk, but his love of science led him to study chemistry and metallurgy in his spare time. During his studies, he learnt about the Bessemer Converter; a means of mass producing steel from iron. However, it had a flaw . Bessemer steel made from the most common type of ore was brittle as it had too much phosphorus. Sidney was told that “The man who eliminates phosphorus by means of the Bessemer Converter will make his fortune”. He was convinced he had the answer! He partnered up with his cousin Percy Carlyle Gilchrist, the work's chemist at Blaenavon Ironworks, where they conducted experiments in their own time. They developed a special lining for the converter which solved the problem. Steelworks in Europe and Russia hurried to use their invention, and the rich industrialist Andrew Carnegie quickly bought the rights to use it in America.
Sidney’s glory was short lived. He died aged just 35, as a result of lung damage caused by his experiments.
Where to Visit?
Blaenavon Ironworks, where Sidney and his cousin carried out their pioneering experiments
Visit Blaenavon World Heritage Centre to find out what Blaenavon was like when Sidney lived here.
16 April 1850
01 February 1885