Foucault

Foucault, Jean Bernard (1819-1868), a French physicist, was born at Paris. He studied medicine, but afterwards gave himself to physical science. He made improvements upon Daguerre's methods in photography, and made researches into the sun's light, polarisation, binocular vision, the passage of light through air and water, and the use of the pendulum in ascertaining the diurnal motion of the earth. [Foucault Pendulum.]