1839 The idea of sending still images via the telegraph traces its roots to 1839. At that time Edmond Becquerel, a French physicist interested in the study of light, found that when two pieces of metal were immersed in an electrolyte, an electrical charge developed when one of the pieces was illuminated. Although Becquerel had discovered the electrochemical effects of light he did not offer any practical suggestion for its use
1842, Alexander Bain proposed a facsimile telegraph transmission system based on Becquerel's discovery. Bain proposed that metallic letters of the alphabet could be transmitted chemically. Electrified metal letters could be scanned by a pendulum device and reproduced at the other end of the telegraph wire by a synchronised pendulum contacting a piece of chemical paper
1843 Alexander Bain (Chemical Telegraph, Patented first)
1848 Frederick Bakewell (Chemical Telegraph, Patented, first working modell)
1851 Hipp (Electrical, Mechanical method)
1855 Caselli (Pantelegraph or Autotelegraph)
1860 Meyer (Kopiertelegraph)
1861 Barnes (Typotelegraph, electrochemical method)
1862 Bonelli (Bonellische Telegraphen)
1865 Gérard, Hubert, Edison
1867 Lenoir (Electrical, Mechanical method)
1869 ´D Arlincourt (Synhronysizing)
1870-1879 Sawyer,
De Hondt (1874),
Little,
Dillon.
1881 Shelford Bidwell (Scanning Phototelegraph)
1887 Ó Brien (Teleautograph)
1888 Elisha Gray (Teleautograph),
Tiffany (Teleautograph),
Mac Pherson (Teleautograph),
Ritchie (Telewriter),
1880-1889 Denison,
Delany,
Parcelle (1882),
Brooks (1884)
1890-1898
Hummel (Telediagraph),
Amstutz, (Electrograph)
Dulany, (Electrograph)
Palmer, (Electrograph)
Mills (Electrograph),
Sheehy (1893)
1903 Korn (Photographic Teleautograph)
1900-1909
Thorne Baker (Teleautograph),
Sémat (Téléautocopiste),
Carbonelle (Membran method),
Korn (second Photographic Teleautograph),
Cerebotani (Facsimile Telegraph),
Grzanna (Grzannagraphen),
Gras, Rickinson, Willoughby, Walter (all Static method)
1925 Eduard Belin (Belinograph
(C) Marius Rensen