Heliograph definition

A device for transmitting messages by reflecting sunlight.

A device capable of imaging the surface and outer regions of the sun.

To send (a message) by heliograph.

To send a heliograph.

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.

To signal or communicate by heliograph.

(intransitive) To send a heliograph.