Sidney Gilchrist Thomas

Sidney Gilchrist Thomas
Sidney Gilchrist Thomas
Born	16 April 1850 Canonbury,London
Died	1 February 1885(1885-03)(aged 34)
Nationality	English

Sidney Gilchrist Thomas(16 April 1850 – 1 February 1885) was anEnglishinventor, best known for his role in the iron and steel industry.

Life

Thomas was born atCanonbury,London,and was educated atDulwich College.His father, a Welshman, was in theCivil Service,and his mother was the daughter of the Rev. James Gilchrist. His father's death left the family with a considerably reduced income, so Thomas gave up his original idea of becoming a doctor and obtained an appointment as apolice courtclerk, which he kept until May 1879.

During these twelve years, besides the work of a busy police court, which brought him into intimate contact with social problems, he found time to studychemistry,and attended lectures at the Birkbeck Institute (which later becameBirkbeck College). George Chaloner, the chemistry teacher at the Institute, remarked one evening that "the man who eliminates phosphorus by means of theBessemer converterwill make his fortune. "This caught the attention of Thomas, and he set himself the task of solving the problem of eliminatingphosphorusfromironproduced by Bessemer converters.By the end of 1875 he was convinced that he had discovered a method. He communicated his theory to his cousin,Percy Gilchrist,who was a chemist at the formerBlaenavon Ironworks,Blaenavonin Wales, and experiments were made which proved satisfactory. Edward Martin, manager of the Blaenavon Works, gave facilities for conducting the experiments on a larger scaleand undertook to help in taking out apatent.In March 1878, the first public announcement of the discovery was made at the meeting of the Iron and Steel Institute; Thomas and Gilchrist took out a patent in May,but without attracting much attention. In September a paper was written by Thomas and Gilchrist on the "Elimination of Phosphorus in the Bessemer Converter" for the autumn meeting of this institute, but it was not read until May 1879. Thomas, however, made the acquaintance ofEdward Windsor Richards,the manager ofBolckow Vaughan& Co's works at Cleveland, Yorkshire, whom he interested in the process, and from this time the success of the invention was assured and domestic and foreign patents were taken out.

The "basic process" invented by Thomas, also known as theGilchrist–Thomas process,was especially valuable on the continent of Europe, where the proportion of phosphoric iron is much larger than in Britain, and both in Belgium and in Germany the name of the inventor became more widely known than in his own country. In the United States, although non-phosphoric iron largely predominated, immense interest was taken in the invention.The improved process resulted in much moreslagforming in the converter. Thomas discovered that this "basic slag" could be useful and profitable as aphosphatefertiliser,known as Thomas meal.

In 1883, jointly withGeorge James Snelus,who had previously discovered the process but had failed to develop it, he was awarded theBessemer Gold Medalof theIron and Steel Institutefor their work on dephosphorisation.

Thomas had been overworking for years, and his lungs became affected. A long sea voyage and a residence in Egypt proved unavailing in restoring his health; he died in Paris in 1885 and was buried atPassy.

Legacy

He had whatWilliam Ewart Gladstone,in a review of theMemoirspublished in 1891, described as an "enthusiasm of humanity," and he left his fortune to be used forphilanthropicwork. A police court mission was endowed in his memory.

In July 1960 an obelisk dedicated to his memory was erected in South Wales by theNewport and District Metallurgical Societyin conjunction with the Iron and Steel Institute. Financial contributions came from many sources and reflected acknowledgment of his work from the United Kingdom and other countries. The formerAmerican Society for Metals,in 1985, struck a commemorative plaque in recognition of the historical importance of the ironworks and honouring his work there. The obelisk and plaque may be seen at the ironworks.

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References

Attribution

• Burnie, Robert William (1898)."Thomas, Sidney Gilchrist".InLee, Sidney(ed.).Dictionary of National Biography.Vol. 56. London: Smith, Elder & Co. p. 190-192.
• This article incorporates text from a publication now in thepublic domain:Chisholm, Hugh,ed. (1911). "Thomas, Sidney Gilchrist".Encyclopædia Britannica(11th ed.). Cambridge University Press.