出典:Wikipedia
出典:『Wikipedia』 (2011/04/04 18:54 UTC 版)
The meridian circle, transit circle, or transit telescope is an instrument for observing the time of stars passing the meridian, at the same time measuring its angular distance from the zenith. The idea of having an instrument (quadrant) fixed in the plane of the meridian occurred even to the ancient astronomers and is mentioned by Ptolemy, but it was not carried into practice until Tycho Brahe constructed a large meridian quadrant.