Fessenden, Reginald Aubrey
Fessenden, Reginald Aubrey (1866-1932), a United States engineer and electrical inventor. Fessenden originated the principle of AM (amplitude modulated) radio by developing a method of modifying the intensity of radio waves. On Christmas Eve, 1906, he made the first broadcast of speech and music. Fessenden's inventions include an improved radio receiver, a radio direction finder, an echo sounder (depth finder), and a turboelectric drive for battleships.
Fessenden was born in Quebec Province, Canada, the son of United States citizens. After attending Bishop's College, Quebec, he was head chemist in Thomas Edison's laboratory, 1887-90. Fessenden taught engineering at Western University of Pennsylvania (now the University of Pittsburgh), 1893-1900, and was later a consulting engineer.