HELIOSCOPE
He"li*o*scope, n. Etym: [Helio- + -scope: cf. F. hélioscope.]
(Astron.)
Defn: A telescope or instrument for viewing the sun without injury to the eyes, as through colored glasses, or with mirrors which reflect but a small portion of light. — He`li*o*scop`ic, a.
HELIOSTAT
He"li*o*stat, n. Etym: [Helio- + Gr. héliostate.]
Defn: An instrument consisting of a mirror moved by clockwork, by which a sunbeam is made apparently stationary, by being steadily directed to one spot during the whole of its diurnal period; also, a geodetic heliotrope.
HELIOTROPE
He"li*o*trope, n. Etym: [F. héliotrope, L. heliotropium, Gr.
Heliacal, Trope.]
1. (Anc. Astron.)
Defn: An instrument or machine for showing when the sun arrived at the tropics and equinoctial line.
2. (Bot.)
Defn: A plant of the genus Heliotropium; — called also turnsole and girasole. H. Peruvianum is the commonly cultivated species with fragrant flowers.
3. (Geodesy & Signal Service)