heliographic, a.
(hiːlɪəʊˈgræfɪk)
[f. helio- + -graphic. Cf. F. héliographique.]
1. Pertaining to the description of the sun.
heliographic latitude or heliographic longitude: the latitude or longitude of points on the sun's surface, referred to the sun's equator and to a meridian passing through the node of this with the ecliptic. (Cf. geographic.)
| 1706 Phillips (ed. Kersey) s.v. Charts, Heliographick Charts, Descriptions of the Sun's Body, and of its Maculæ, or Spots. 1879 Newcomb & Holden Astron. 289 The heliographic latitude of the spot, or its angular distance from the solar equator. |
2. † a. Belonging to photography; photographic.
| 1840 Proc. Amer. Phil. Soc. I. 181 Dr. Patterson exhibited some specimens of the Heliographic Art (Daguerreotype). 1855 tr. Niépce de St. Victor's Researches i. 44 The heliographic images coloured by its light. |
b. Belonging to photographic engraving: see heliograph 1, heliography 3.
| 1851 R. Hunt Photography ix. 107 Producing a better effect than was given by the Heliographic process in several hours. 1855 Lacan Pref. Niépce de St. Victor's Researches 21 The remarkable works which heliographic engraving has produced. 1858 Photogr. Notes III. 260/2 The heliographic image formed by the sensitive varnish acted on by the light. 1875 tr. Vogel's Chem. Light i. 12 Printed off from heliographic plates. |
3. Pertaining to or obtained by the signalling apparatus called a heliograph (see heliograph 4).
| 1880 Standard 8 Apr. 5/3 Hughes's Brigade is in heliographic communication with Khelat-i-Ghilzai. 1897 Ld. Roberts 41 Yrs. India II. liv. 258 The more perfect heliographic apparatus which is now available. |
So helioˈgraphical a. = heliographic; helioˈgraphically adv., by means of a heliograph (sense 4 in quot.).
| 1884 Sat. Rev. 26 Jan. 120 How the relieving force first came heliographically into communication with Candahar. |