dipleidoscope

English

Etymology

Ancient Greek

Noun

dipleidoscope (plural dipleidoscopes)

1. (astronomy) An instrument for determining the time of apparent noon. It consists of two mirrors and a plane glass in the form of a prism, so that, by the reflections of the sun's rays from their surfaces, two images are presented to the eye, moving in opposite directions, and coinciding at the instant the sun's centre is on the meridian.

Part or all of this entry has been imported from the 1913 edition of Webster’s Dictionary, which is now free of copyright and hence in the public domain. The imported definitions may be significantly out of date, and any more recent senses may be completely missing.
(See the entry for “dipleidoscope”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.)