Born Dec. 29, 1843, in Aillant-sur-Milleron, Loire Department; died Oct. 14, 1918, in Vincennes. French physicist and electrical engineer; member of the Paris Academy of Sciences (1886). Graduated from the Mining College in Paris in 1866. Until 1872 he studied mechanical engineering. Beginning in 1885 he taught in institutions of higher learning in France.
During the Franco-Prussian War (1870–71), Deprez made a device for measuring the velocity of a shell at the muzzle of a gun. In 1878 he devised a number of instruments for road dynamometric measurements. In 1881, at the First International Congress of Electricians, he delivered a paper on the transmission and distribution of electrical energy. He built the first experimental electric transmission line at the Munich exhibition in 1882 (from Miesbach to Munich). On this line, which was 57 km long, he transmitted over a telegraph wire direct current at 1,500–2,000 volts from a generator driven by a steam engine to an electric motor connected to a pump. He built several electric transmission lines in France, the most important of which was a 5,000–6,000-volt DC line between Creil and Paris (56 km), with an efficiency of about 45 percent.
WORKS“Elektricheskaia peredacha raboty na bol’shoe rasstoianie.” Elektrichestvo, 1881, nos. 15–16.
“O raspredelenii elektricheskikh tokov.” Elektrichestvo, 1881, no. 20.
“O gal’vanometre, pokazaniia kotorogo proportsional’ny sile toka.” Elektrichestvo, 1884, no. 24.
“O konstruktsii dinamomashin dlia peredachi raboty na rasstoianie.” Elektrichestvo, 1886, no. 6.