History of The Telephone - Early Telephone Developments

Early Telephone Developments

The following is a brief summary of the history of the development of the telephone:

• 1667: Robert Hooke invented a string telephone that conveyed sounds over an extended wire by mechanical vibrations.
• 1753: Charles Morrison proposes the idea that electricity can be used to transmit messages, by using different wires for each letter.
• 1844: Innocenzo Manzetti first mooted the idea of a “speaking telegraph” (telephone).
• 1854: Charles Bourseul writes a memorandum on the principles of the telephone. (See the article: "Transmission électrique de la parole", L'Illustration, Paris, 26 August 1854.)
• 1854: Antonio Meucci demonstrates an electric voice-operated device in New York; it is not clear what kind of device he demonstrated.
• 1861: Philipp Reis constructs the first speech-transmitting telephone
• December 28, 1871: Antonio Meucci files a patent caveat No. 3353 at the U.S. Patent Office for a device he named "Sound Telegraph".
• 1872: Elisha Gray establishes Western Electric Manufacturing Company.
• July 1, 1875: Bell uses a bi-directional "gallows" telephone that was able to transmit "voicelike sounds", but not clear speech. Both the transmitter and the receiver were identical membrane electromagnet instruments.
• 1875: Thomas Edison experiments with acoustic telegraphy and in November builds an electro-dynamic receiver, but does not exploit it.
• 1875: Hungarian Tivadar Puskas (the inventor of telephone exchange) arrived in the USA.
• April 6, 1875: Bell's U.S. Patent 161,739 "Transmitters and Receivers for Electric Telegraphs" is granted. This uses multiple vibrating steel reeds in make-break circuits, and the concept of multiplexed frequencies.
• January 20, 1876: Bell signs and notarizes his patent application for the telephone.
• February 11, 1876: Elisha Gray designs a liquid transmitter for use with a telephone, but does not build one.
• March 7, 1876: Bell's U.S. patent No. 174,465 for the telephone is granted.
• March 10, 1876: Bell transmits the sentence: "Mr. Watson, come here! I want to see you!" using a liquid transmitter and an electromagnetic receiver.
• January 30, 1877: Bell's U.S. patent No. 186,787 is granted for an electromagnetic telephone using permanent magnets, iron diaphragms, and a call bell.
• April 27, 1877: Edison files for a patent on a carbon (graphite) transmitter. Patent No. 474,230 was granted on May 3, 1892, after a 15-year delay because of litigation. Edison was granted patent No. 222,390 for a carbon granules transmitter in 1879.
• 1877: First long-distance telephone line
• 1915: First U.S. coast-to-coast long-distance telephone call, ceremoniously inaugurated by A.G. Bell in New York City and his former assistant Thomas Augustus Watson in San Francisco, California.