Hippolyte Fizeau

Armand Hippolyte Louis Fizeau (1819—1896), French physicist, was born at Paris on September 23, 1819. 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 French Academy in 1860 and of the Bureau des Longitudes in 1878.