Foucault Jean Bernard Léon
Fou·cault
(fo͞o-kō′), Jean Bernard Léon 1819-1868. French physicist who measured the velocity of light (1850) and proved that light moves more slowly in water than in air. In 1857 he constructed the first gyroscope.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.