Hippolyte Fizeau
Armand Hippolyte Louis Fizeau (
September 23,
1819-
1896),
French
physicist, was born at
Paris. His earliest work was concerned with improvements in photographic processes; and then, in association with
J. B. L. Foucault, he engaged in a series of investigations on the
interference of light and heat. In
1849 he published the first results obtained by his method for determining the
speed of light (see
Fizeau-Foucault apparatus), and in
1850 with E. Gounelle measured the speed of
electricity.
In 1853 he described the employment of the capacitor (then called the condenser) as a means for increasing the efficiency of the induction coil. Subsequently he studied the thermal expansion of solids, and applied the phenomena of interference of light to the measurement of the dilatations of crystals. He died at Venteuil September 18, 1896. He became a member of the Académie française in 1860 and of the Bureau des Longitudes in 1878.