Jesse Ramsden

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Born: 15 Oct 1735 in Halifax, Yorkshire, England
Died: 5 Nov 1800 in Brighton, Sussex, England

Jesse Ramsden was apprenticed to a cloth maker, but at the age of 23 he chose to become an apprentice to a mathematical instrument maker. By the age of 27 he had his own business in London where he became acknowledged as the most skilful designer of mathematical, astronomical, surveying and navigational instruments in the 18th Century.

The French scientist N Cassegrain proposed a design of a reflecting telescope in 1672. It was Ramsden, however, 100 years later who found that this design reduces blurring of the image caused by the sphericity of the lenses or mirrors. He was elected Fellow of the Royal Society (1786) and received the Copley Medal in 1795.