Message #107774

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Large astrolabe



Ibn Yunus accurately observed more than 10,000 entries for the sun's position for many years using a large astrolabe with a diameter of nearly 1.4 meters.[35]





Mechanical geared astrolabe



The first mechanical astrolabes with gears were invented in the Muslim world, and were perfected by Ibn Samh (c. 1020). One such device with eight gear-wheels was also constructed by Abū Rayhān al-Bīrūnī in 996.

These can be considered as an ancestor of the mechanical clocks developed by later Muslim engineers.

 




Navigational astrolabe



The first navigational astrolabe was invented in the Islamic world during the Middle Ages, and employed the use of a polar projection system.






Orthographical astrolabe



Abu Rayhan al-Biruni invented and wrote the earliest treatise on the orthographical astrolabe in the 1000s.