Taqī al-Dīn al-Rāṣid was the founder and director of the first Ottoman observatory. He was appointed head-astronomer (Müneccimbaşı) by Sultan Selīm II upon the death of Muṣṭafā ibn ʿAlī al-Muwaqqit in 1571. He was trained in the fields of mathematics, astronomy, optics, and mechanics and has more than 20 works. He advanced the arithmetic of decimal fractions and used them in the calculation of astronomical tables; and he was the first astronomer to use an automatic, mechanical clock for his astronomical observations. He was educated in both Egyptian and Damascus madrasas.