A popular handbook and atlas of astronomy, designed as a complete guide to a knowledge of the heavenly bodies and as an aid to those possessing telescopes (1891)
Peck, William, Sir, 1862-1925 · New York, G. P. Putnam's Sons · leaf 155
hichshows that it must have been considered capable of measuring angleswith considerable accuracy. Up to this time astronomers could not meet one very great want. They could not, even with approximate accuracy, by mechanical means determine time. Of course, if the sun were above the horizon, the… … Fig. 23. the ecliptic astrolabe. ASTRONOMICAL INSTRUMENTS. 93 The principal instrument used for this purpose was the clepsydra, or water-clock, which was simply a vessel ofa particular shape with a small aperture at the bottom through which the water flowed, the time beingindicated by the height of…
Astronomy
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