Timeline of The Telephone - 1844 To 1875

1844 To 1875

• 1844: Innocenzo Manzetti first suggested the idea of a “speaking telegraph” (telephone).
• 1849: Antonio Meucci demonstrates a communicating device to individuals in Havana. It is disputed if this is an electromagnetic telephone, but is said to involve direct transmission of electricity into the user's body.
• 1854: Charles Bourseul publishes a description of a make-break telephone transmitter and receiver in L'Illustration, (Paris) but does not construct a working instrument
• 1854: Antonio Meucci demonstrates an electric voice operated device in New York, but it is not clear what kind of device he demonstrated.
• 1860: Johann Philipp Reis of Germany demonstrates a make-break transmitter after the design of Bourseul and a knitting needle receiver. Witnesses said they heard human voices being transmitted.
• 1861: Johann Philipp Reis manages to transfer voice electrically over a distance of 340 feet, see Reis' telephone. Reis used his Telephone (the word also invented by Reis) to transmit his phrase "The horse does not eat cucumber salad". This phrase in German is hard to understand acoustically so Reis used it to prove if speech can be recognized successfully at the receiving end.
• 1864: in an attempt to give his musical automaton a voice, Innocenzo Manzetti invents the 'Speaking telegraph'. He shows no interest in patenting his device, but it is reported in newspapers.
• 1865: Meucci reads of Manzetti's invention and writes to the editors of two newspapers claiming priority and quoting his first experiment in 1849. He writes "I do not wish to deny Mr. Manzetti his invention, I only wish to observe that two thoughts could be found to contain the same discovery, and that by uniting the two ideas one can more easily reach the certainty about a thing this important." If he reads Meucci's offer of collaboration, Manzetti does not respond.
• 1871: Antonio Meucci files a patent caveat (a statement of intention to patent) for a Sound Telegraph, but it does not describe an electromagnetic telephone.
• 1872: Elisha Gray founded Western Electric Manufacturing Company.
• 1872: Professor Vanderwyde demonstrated Reis's telephone in New York.
• July 1873: Thomas Edison notes variable resistance in carbon grains due to pressure, builds a rheostat based on the principle but abandons it because of its sensitivity to vibration.
• May 1874: Gray invents electromagnet device for transmitting musical tones. Some of his receivers use a metallic diaphragm.
• 29 December 1874: Gray demonstrates his musical tones device and transmitted "familiar melodies through telegraph wire" at the Presbyterian Church in Highland Park, Illinois.
• 2 June 1875: Alexander Graham Bell transmits the sound of a plucked steel reed using electromagnet instruments.
• 1 July 1875: Bell uses a bi-directional "gallows" telephone that was able to transmit "indistinct but 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.