Al-Farghani (ca. 860)
Al-Farghani wrote on the astrolabe, explaining the mathematical theory behind the instrument and correcting faulty geometrical constructions of the central disc that were current then. His most famous book Kitab fi Harakat Al-Samawiyah wa Jaamai Ilm al-Nujum on cosmography contains thirty chapters including a description of the inhabited part of the earth, its size, the distances of the heavenly bodies from the earth and their sizes, as well as other phenomena.
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by: FSTC Limited, Mon 16 July, 2007