- a permanent image formed on a glass plate by an early photographic process
- a signaling device that uses a mirror to flash the sun's rays to a distant observer
Origin of heliographhelio- + -graph
- A device for transmitting messages by reflecting sunlight.
- A device capable of imaging the surface and outer regions of the sun.
verbhe·li·o·graphed, he·li·o·graph·ing, he·li·o·graphs
(third-person singular simple present heliographs, present participle heliographing, simple past and past participle heliographed)
- To send a message by heliograph.
- (intransitive) To send a heliograph.
From helio- + -graph.