The '''astrolabe''' was a compact instrument used to observe and calculate the position of celestial bodies before the invention of the [[sextant]].
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The '''astrolabe''' was a compact round disc used to observe and calculate the position of celestial bodies before the invention of the [[sextant]]. It was the most widely used astronomical instrument of the Islamic and Medieval periods.
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Astrolabes usually consisted of a flat disc with a sighting rod that could be pivoted to point at the [[Sun]] or bright stars. From the altitude of the Sun or star above the horizon, the local time could be estimated. <ref>A presentation for the Man & Technology Course (ES103) @ SUNY Farmingdale,by Gary Agranat & Dave Delligati, Fall 1980. [http://members.aol.com/chopstcks/gca7sky/astrolabe.htm]</ref>