Medicine: From the Lighthouse

Augustin Jean Fresnel lost his job as an engineer with the French government in 1815 because he opposed Napoleon's return from Elba. Then he turned his fertile, inventive brain to the problem of getting lighthouses to give more light. Little recognized in his short (1788-1827) life, Fresnel (pronounced Fray-nell) wrought an optical revolution and indirectly saved untold lives by junking the mirrors on which lighthouses had long depended, instead put the light source inside a cylindrical lens with multiple-refracting bands at top and bottom. The resulting Fresnel lens (commonly pronounced Frez-nel) still has many maritime uses, is on sale by most...

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