Pětitunový Mark I a Bellův patent prvopočátků telefonu

http://en.wikipedia.org/wiki/Telephone


Early development

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

* 1849 Antonio Meucci, an Italian living in Havana, demonstrates a device later called a telephone. (The demonstration involves direct electrical connections to people.)
* 1854 Charles Bourseul publishes a description of a make-break telephone transmitter and receiver but does not construct a working instrument.
* 1854 Meucci demonstrates an electric telephone in New York. [1]
* 1860 Johann Philipp Reis demonstrates a make-break transmitter after the design of Bourseul.
* 1860 Meucci supposedly demonstrates his telephone on Staten Island.
* 1861 Reis manages to transfer voice electrically over a distance of 340 feet, see Reis' telephone.
* 1871 Meucci files a patent caveat (a statement of intention to patent).
* 1872 Elisha Gray founds Western Electric Manufacturing Company.
* July 1873 Thomas Alva Edison notes variable resistance in carbon grains due to pressure, but shelves the discovery.
* 1874 Gray demonstrates his liquid transmitter telephone at the Highland Park Presbyterian Church.
* 2 June 1875 Alexander Graham Bell first transmits voice.
* 1 July 1875 Bell first uses a bi-directional capable telephone (Both the transmitter and the receiver were identical membrane instruments.)
* 14 February 1876 Bell files his first patent on the telephone.
o Two hours later Gray files his patent caveat.
* 30 January 1877 Bell patents the electro-dynamic transmitter, receiver telephone.