The astrolabe, one of the most important measuring instruments used by the Muslims, was invented in Alexandria in the Greek period. The development of this tool and the invention of the advanced astrolabe were achieved by the Arab Muslims. It was then reintroduced into the West in the Middle Ages.
The Arabs excelled as manufacturers of this instrument. They designed the astrolabe's many forms and sizes with care and calibrated them with extreme accuracy. Examples of these astrolabes, considered works of art, are displayed in many of the world's museums, the most important of which is the Astrolabe of the Bibliotheque de Paris and the Astrolabe of the Library of Alexandria.
Muslims used the astrolabe to determine the correct qibla sighting, which is the direction to Mecca, the angle between one geographical site and another, the angle and elevation of the sun and of celestial bodies, and the cycles and duration of day and night.
The astrolabe played an important role in guiding ships, whether for military or commercial purposes. Many other instruments were developed by the Arabs on the basis of the same principle as the astrolabe for the purpose of navigation.
The many manuscripts explaining how to construct an astrolabe show the Arabs' great interest in the tool. The manuscript from the eighth century after Hijra (fourteenth century AD) held in the Egyptian Dar al-Kutub entitled "Rasaiel fi amal al-astorlab" or "On the manufacture of the Astrolabe" by Mohammad Ibn Ahmad Al-Muzzi is one of the most important of this type.