Astrolabe of Ptolemy: An Ancient Greek 'GPS' that Measured the Movement of the Stars
Louis Moinet Astrolabe Tourbillon - Luxois
Astronomical Observatories in the Classical Islamic Culture - Muslim HeritageMuslim Heritage
Alexandria observatory, 2nd century BC - 2nd century AD. Astronomer using a pre-telescopic sighting instrument, possibly a cross-staff. In Ptolemaic Egypt, the Egyptian tradition merged with Greek astronomy and Babylonian astronomy, with