Dictionary entry

Helioscope

Webster's Dictionary 1913

He″li‐o‐scope (?), n. [Helio- + -scope: cf. F. hélioscope.] (Astron.) 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.