Page:Astronomy for Everybody.djvu/104

This page has been validated.
80
ASTRONOMICAL INSTRUMENTS

no end, and in order to make these investigations other instruments besides the telescope are necessary.


The Meridian Circle and Clock

The problem which demands most attention from the working astronomer in an observatory is the determination of the positions of the heavenly bodies. The prin-

Fig. 16.—A Meridian Instrument.

cipal instrument for making these determinations is the meridian circle, called also a meridian instrument. This consists of a telescope supported on a horizontal east and west axis, at right angles to its length, so that its line of sight can move only along the meridian. If it points

This article is issued from Wikisource. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.