• Webster's Revised Unabridged Dictionary
    • Heliography An early photographic process invented by Nicéphore 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.
    • Heliography Photography.
    • Heliography The description of the sun.
    • Heliography The system, art, or practice of telegraphing, or signaling, with the heliograph.
    • ***
Century Dictionary and Cyclopedia
    • n heliography A method of signaling between distant points by means of the heliograph.
    • n heliography In general, photography; specifically, some special photographic process; photographic engraving. See the extract, and heliographic engraving, under heliographic.
    • n heliography The description and mapping of the surface of the sun.
    • ***
Chambers's Twentieth Century Dictionary
    • ns Heliography a method of communicating swiftly between distant points by means of the sun's rays reflected from mirrors: photography
    • ***


Webster's Revised Unabridged Dictionary
Helio-, + -graphy,
Chambers's Twentieth Century Dictionary
Gr. hēlios, the sun, graphē, a painting—graphein, to write.


In literature:

"American Handbook of the Daguerrotype" by Samuel D. Humphrey
Manuel d'Heliographie et de Photogravure en Relief.
"Photogravure" by Henry R. Blaney