Thomas Stevenson to Faraday   19 November 1859

Private

Edinburgh | Nov. 19. 1859

My dear Sir

Allow me to thank you for your kindness in sending me the notice regarding the polyzonal lens1. In the Pamphlet2 which my brother3 and I were forced although most reluctantly to publish we do not state that Buffon proposed the built lens although there is some doubt even as to this. But one thing is certain that Condorcet most distinctly described it as well as the means which it afforded of correcting spherical aberration. We know therefore that the polyzonal lens as now used in Lighthouses was first invented (for burning purposes only) by Condorcet4 in 1780 while Fresnel was the first to publish and the first to apply it to Lighthouses5[.]

With many thanks for your kind attention in which my brother joins

Believe me | ever faithfully yours | Thomas Stevenson

Professor. Faraday | &c &c &c

Possibly a reference to letter 3673.
Stevenson and Stevenson (1859).
David Stevenson (1815-1886, ODNB). Engineer to the Northern Lighthouse Board.
Marie-Jean-Antoine-Nicholas Caritat, Marquis de Condorcet (1743-1794, DSB). French mathematician.
Fresnel (1822).

Bibliography

FRESNEL,

Augustin Jean (1822): “Extrait d’un Mémoir sur un nouveau système d’éclairage des Phares”, Bull. Soc. Phil., 123-7.

STEVENSON, David and STEVENSON, Thomas (1859): Reply to Sir David Brewster's memorial to the Lord's Commissioners of Her Majesty's Treasury, on the new system of dioptric lights, Edinburgh.

Please cite as “Faraday3682,” in Ɛpsilon: The Michael Faraday Collection accessed on 29 April 2024, https://epsilon.ac.uk/view/faraday/letters/Faraday3682