Telegraph machine. Historical artwork of a Foy- Breguet twin-needle electric telegraph machine (circa 1845). Telegraphs were used to send information as a series of electric pulses. The relative positions of the two needles of the telegraph machine indicated different letters or numbers. Published in La Telegraphie Historique (History of Telegraphy) by Alexis Belloc in 1888 | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Terry, Sheila |
Bildgröße: | 4806 px × 2888 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |