Patents
- U.S. Patent 0,161,739 -- Improvement in Transmitters and Receivers for Electric Telegraphs -- Alexander Graham Bell, issued April 6, 1875
- U.S. Patent 0,166,095 -- Electrical Telegraph for Transmitting Musical Tones -- Elisha Gray, issued July 27, 1875
- U.S. Patent 0,182,996 -- Acoustic Telegraph -- Thomas Edison, issued October 10, 1876
- U.S. Patent 0,186,330 -- Acoustic Electric Telegraphs -- Thomas Edison, issued January 16, 1877
- U.S. Patent 0,200,993 -- Acoustic Telegraphs -- Thomas Edison, issued March 5, 1878
- U.S. Patent 0,203,019 -- Circuits for Acoustic or Telephonic Telegraphs -- Thomas Edison, issued April 30, 1878
- U.S. Patent 0,235,142 -- Acoustic Telegraph -- Thomas Edison, issued December 7, 1880
All five of these Edison patents were assigned to Western Union Telegraph Company of New York.
Read more about this topic: Acoustic Telegraphy