He`li*og"ra*phy (?), n. [Helio- + -graphy.]

Photography. R. Hunt.


© Webster 1913

He`li*og"ra*phy, n.


The description of the sun.


The system, art, or practice of telegraphing, or signaling, with the heliograph.


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.


© Webster 1913

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