German, Aleksandr Petrovich

Born Oct. 20 (Nov. 1), 1874, in Viatka, now Kirov; died Nov. 30, 1953, in Leningrad. Soviet scientist in mining mechanics. Academician of the Academy of Sciences of the USSR (1939).

German graduated from the physics-mathematics department of St. Petersburg University in 1897 and from the St. Petersburg Mining Institute in 1903. He began to teach at the St. Petersburg Mining Institute in 1907 and in 1914 became a professor there. He worked out the theoretical bases of mining mechanics and published works on mining installations and on machines for the heat treatment of metals. In 1912 he was the first to determine analytically the conditions for the optimal thermodynamic output of steam turbines. German provided the exact equation for the theoretical pressure of turbine machines and proved the existence of the law of congruence of individual characteristics for geometrically similar turbines. He demonstrated the existence of typical characteristics of a series of turbines, in this way pointing out the correct methods for the development of Soviet turbine machine construction on the principle of lot production. German carried out comprehensive analytical research on the dynamics of mine hoisting. He was awarded the Order of Lenin and three other orders.