Quadrant Astrolabe from Damascus by Muhammad al-Sakasi al-Jarkasi (fruitwood covered by lacquered paper). Several forms of quadrants were invented by Muslims. Brass astrolabes were developed in much of the Islamic world, chiefly as an aid to finding the qibla, the direction that should be faced when Muslims pray. Among them was the sine quadrant used for astronomical calculations and various forms of the horary quadrant, used to determine time (especially the times of prayer) by observations of the Sun or stars. Circa 1308.