| 单词 | parallactic instrument |
| 释义 | > as lemmasparallactic instrument parallactic instrument n. historical an instrument invented by Ptolemy, consisting of three hinged rods (one vertical, one aligned along the observer's line of sight, and the third fixing the angle between the first two), used for calculating the parallax of the moon. ΚΠ 1687 Philos. Trans. 1686–7 (Royal Soc.) 16 404 The Meridian Altitude of the Sun in the summer Solstice was observed by the Parallactick instrument of Ptolemy. 1779 Philos. Trans. (Royal Soc.) 69 164 A parallactic instrument, with a common telescope five feet long, and a reticule rhomboide. 1990 Jrnl. Hist. Ideas 51 356 Of Copernicus in particular Tycho cherished the parallactic instrument which an assistant had brought back from an observing expedition to Frauenburg. < as lemmas |
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