Person: Ramsden, Jesse

Jesse Ramsden was an English instrument maker who made improvements to telescopes.

Ramsden spent much time at Dollond's house learning about optical instruments.
Marriage gave Ramsden a share in the patent that John Dollond had taken out on his most famous invention, the achromatic lens.
Ramsden soon opened a new business in Haymarket, near Little Suffolk Street.
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.
Ramsden produced such an instrument in 1767 but it did not give as accurate results as was hoped.
A second version produced in 1775 was considerably better and led to Ramsden being awarded £300 two years later by the longitude commissioners.
Indeed Ramsden continued to expand his business, enlarging his premises in 1780.
The procedures adopted by Ramsden and Troughton for correcting initial dividing marks are also described.
Ramsden's health deteriorated and he was advised to go to Brighton to aid his recovery.
This did not happen and Ramsden died there.

Born 15 October 1735, Salterhebble, near Halifax, Yorkshire, England. Died 5 November 1800, Brighton, Sussex, England.

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Astronomy, Origin England, Physics

Thank you to the contributors under CC BY-SA 4.0!

O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive