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The Collaborative International Dictionary

Heliograph \He"li*o*graph\ (h[=e]"l[i^]*[-o]*gr[.a]f), n.

  1. A picture taken by heliography; a photograph.

  2. An instrument for taking photographs of the sun.

  3. An apparatus for telegraphing by means of the sun's rays. See Heliotrope, 3.


Heliograph \He"li*o*graph\ (h[=e]"l[i^]*[-o]*gr[.a]f), v. t.

  1. To telegraph, or signal, with a heliograph.

  2. To photograph by sunlight.

Douglas Harper's Etymology Dictionary

product of a certain type of engraving process, 1853, from helio- + -graph "something written." Earlier, "a description of the sun" (1706, implied in heliographic). Heliography (1845 in the engraving sense) also (1840) was an early term for what came to be called photography.


n. 1 An apparatus for signalling by means of a moveable mirror which reflects flashes of sunlight. 2 A heliogram. 3 An instrument for measuring the intensity of sunlight. 4 A device for photographing the sun. 5 (context obsolete English) A photograph. vb. 1 (context transitive English) To send a message by heliograph. 2 (context intransitive English) To send a heliograph. 3 (cx transitive dated English) To photograph by sunlight.

  1. n. an apparatus for sending telegraphic messages by using a mirror to turn the sun's rays off and on

  2. v. signal by means of a mirror and the using the sun's rays


A heliograph (, meaning "sun", and , meaning "write") is a wireless solar telegraph that signals by flashes of sunlight (generally using Morse code) reflected by a mirror. The flashes are produced by momentarily pivoting the mirror, or by interrupting the beam with a shutter. The heliograph was a simple but effective instrument for instantaneous optical communication over long distances during the late 19th and early 20th century. Its main uses were military, survey and forest protection work. Heliographs were standard issue in the British and Australian armies until the 1960s, and were used by the Pakistani army as late as 1975.

Heliograph (disambiguation)

Heliograph is a word derived from helios ( Greek Ἥλιος / ἥλιος "sun") and graphein (γραφειν "to write"). It has several uses:

  • the heliograph, a device used for optical signalling
  • a type of sunshine recorder
  • a solar telescope, a telescope especially adapted for viewing the surface of the sun (obsolete).
  • a camera especially adapted for photographing the sun; also called a photoheliograph (obsolete).
  • heliography, the photographic process used to make the earliest known permanent photograph from nature

Usage examples of "heliograph".

It was a dimensionless point of light, as if a star had been clawed from the sky by one of those cruel peaks, and I imagined that some smooth rock surface was catching the sunlight and heliographing it straight into my eyes.

Sepoy Prem Singh, climbing several times out of a window in the tower with a heliograph, and signaling outside to the Malakand under a hot fire from sungars in every direction.

On July 10th General French, surveying from a lofty mountain peak the vast expanse of the field of operations, with his heliograph calling up responsive twinkles over one hundred miles of country, gave the order for the convergence of four columns upon the valley in which he knew Scheepers to be lurking.

On October 31st the force remained on the defensive, but early on November 1st the gleaming of two heliographs, one to the north-east and one to the south-west, told that two British columns, those of De Lisle and of Barter, were hastening to the rescue.

The original autograph, which is preserved in the treasury of Sacro Convento, has been very well reproduced by heliograph.

The burghers in the valley below could see all day the twinkle of British heliographs from every hill, while at night the constant flash of signals told of the sleepless vigilance which hemmed them in.

Far on the flanks the twinkling heliographs revealed the position of the wide-spread wings.

It was a dimensionless point of light, as if a star had been clawed from the sky by one of those cruel peaks, and I imagined that some smooth rock surface was catching the sunlight and heliographing it straight into my eyes.

The mirror was simply a heliographing gadget of a commercial type which had been on the market twenty or thirty years before, and sometimes used by the army for signaling purposes.

Captain Gahlos used the heliograph mounted on the palace roof to signal the immediate unbarring and opening of the south and west gates.

North along the chain of heliograph stations a light began to blink, a slotted cover like a lever-operated Venetian blind slapping open and closed over a mirror-backed carbide lamp.

The heliographs were simple portable signaling devices, just mirrors on foldaway tripods.

Musta heliographed the garrison from the carob grove and given our position.

And once we have made peace, we will have relays of Readers, and the heliograph will become obsolete.

The land on both sides of the Griffen Road was owned by Charles Griffen, who was the biggest dairy farmer south of Mechanic Falls, and from Schoolyard Hill you could see Griffen's huge barn with its aluminum roof glittering in the sun like a monstrous heliograph.