Invention of the solid‐state amplifier
The obituary column of a recent issue of Physics Today carried the announcement of the death of Julius E. Lilienfeld at his home in the Virgin Islands. Dr. Lilienfeld was a native of Poland, formerly a professor of physics at the University of Leipzig, and became a United States citizen in 1935. The announcement of the passing of Dr. Lilienfeld recalled to mind an experience which the author had in 1953 when he was engaged in a patent search in connection with the development of the germanium transistor. The patent search disclosed three patents granted in the years 1930, 1932, and 1935, respectively, to Julius Edgar Lilienfeld of Brooklyn and Cedarhurst, New York. The attorney who prepared the patent was Fred'k F. Schuets. A brief inquiry failed to locate either the inventor or his attorney and, inasmuch as the patents had already lapsed, the matter was dropped.