Parsons diamonds

OBJECTS OF ENGINEERING-black diamonds

Parson's diamonds
Parsons’ diamonds

Charles Algernon Parsons’ diamonds

Although best known as the inventor of the steam turbine (a notebook about which we hold), Parsons also spent 40 years and a lot of money attempting to make diamonds. The results of his experiments were presented to the Royal Society in 1907 in a paper entitled ‘Some Notes on Carbon at High Temperatures and Pressures‘.

In 1797 it was discovered that diamonds were pure carbon, this led many to try to create diamonds from carbon: no doubt tempted by the huge profits which could be made from turning a cheap material into an expensive one. The earliest successes were reported by James Ballantyne Hannay (1879) and Ferdinand Frédéric Henri Moissan (1893). Their method involved heating charcoal at up to 3500 °C with iron inside a carbon crucible in a furnace. Hannay used a flame-heated tube, Moissan applied his newly developed electric arc furnace, in which an electric arc was struck between carbon rods inside blocks of lime. The molten iron was then rapidly cooled by immersion in water. The contraction generated by the cooling supposedly produced the high pressure required to transform graphite into diamond. Moissan published his work in a series of articles in the 1890s. Both claimed to have created diamonds.

Parsons attempted to recreate both of these techniques, until finally giving up and declaring that these methods did not work and therefore concluding that Hannay and Moissan had made false claims of success. Parsons also developed his own techniques, he believed to have made diamonds but these did not stand up to material testing.

Parsons was known for his painstakingly accurate approach and methodical record keeping; all his resulting samples were preserved for further analysis by an independent party (hence being found wanting). However, an employee of his gave the Institution nine samples during our summer meeting in Newcastle, 1902 and thus we hold part of this intriguing physical archive.

Parsons wrote some of the first articles on high-pressure high-temperature (HPHT) diamonds, in which he claimed to have produced small diamonds. However, in 1928 he authorized Dr. C.H. Desch to publish an article in which he stated his belief that no synthetic diamonds had been produced up to that date, evidently he had decided his ‘diamonds’ were not in fact really diamonds. He suggested that most diamonds that had been produced up to that point were likely synthetic spinel.

Archives, Institution of Mechanical Engineering

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