Smoke signalling. Historical artwork of ancient Greek warriors using smoke signals to communicate. This was an early form of optical communication. Successive beacons on high points of land could be lit to transmit a signal across long distances. From La Telegraphie Historique by Alexis Belloc (1888) | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Terry, Sheila |
Bildgröße: | 3159 px × 3148 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |