Helioscope

A helioscope is an instrument used in observing the sun and sun spots. The helioscope was first used by Benedetto Castelli (1578-1643) and refined by Galileo (1564–1642). The method involves projecting an image of the sun onto a white sheet of paper suspended in a darkened room with the use of a telescope. The first machina helioscopica or helio...
Found on http://en.wikipedia.org/wiki/Helioscope

Helioscope

• (n.) 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.
Found on http://thinkexist.com/dictionary/meaning/helioscope/

Helioscope

He'li·o·scope noun [ Helio- + -scope : confer French 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
Found on http://www.encyclo.co.uk/webster/H/28

Helioscope

A helioscope is a telescope fitted for viewing the sun without damage to the eyes, as when the image of the sun is received upon mirrors formed simply of surfaces of transparent glass which reflect only a small portion of the light.
Found on http://www.probertencyclopaedia.com/browse/GH.HTM

helioscope

helioscope A telescope with a great focal length that receives images of the sun from plane mirrors attached to it; so, the viewer's eyes are protected from the sun's glare.
Found on http://www.wordinfo.info/words/index/info/view_unit/963/4

helioscope

instrument for observing sun without injury to the eyes
Found on http://phrontistery.info/h.html
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