The Collaborative International Dictionary
Heliography \He`li*og"ra*phy\, n.
[Helio- + -graphy.] The description of the sun.
The system, art, or practice of telegraphing, or signaling, with the heliograph.
An early photographic process invented by Nic['e]phore Niepce, and still used in photo-engraving. It consists essentially in exposing under a design or in a camera a polished metal plate coated with a preparation of asphalt, and subsequently treating the plate with a suitable solvent. The light renders insoluble those parts of the film which is strikes, and so a permanent image is formed, which can be etched upon the plate by the use of acid.
Photography. [Archaic.]
--R. Hunt.
Wiktionary
n. 1 The scientific study of the sun 2 The art of making a heliograph 3 The system of signalling by heliograph
Wikipedia
Heliography (in French, héliographie) is the photographic process invented by Joseph Nicéphore Niépce around 1822, which he used to make the earliest known surviving photograph from nature, View from the Window at Le Gras (1826 or 1827). The process used Bitumen of Judea, a naturally occurring asphalt, as a coating on glass or metal. It hardened in proportion to its exposure to light. When the plate was washed with oil of lavender, only the hardened areas remained.
The word has also been used to refer to other phenomena: for description of the sun (cf. geography), for photography in general, for signalling by heliograph (a device less commonly called a heliotrope or helio-telegraph), and for photography of the sun.
The abbreviations héliog. or héliogr., found on old reproductions, may stand for the French word héliogravure, and can then refer to any form of photogravure.
Usage examples of "heliography".
It was an obvious application of the new agent and accomplished with the old classical and unimproved induction coil, scarcely anything more than another kind of heliography.