Iraq, dated 927/28
Height 22.5 cm (8 13/16 in.), diameter 17.5 cm (6 7/8 in.)
LNS 36 M
The astrolabe, an astronomical instrument used for observing planetary movements, was
indispensable for navigation. It was used also to determine the location of the Kaaba in
Makka, in which direction all Muslims face during prayer.
Planispheric. or flat, astrolabes, such as this example, were more common than the linear or
spherical types. In planispheric astrolabes the celestial sphere was drawn on a flat surface and
represented on one plate.
This astrolabe, made of cast bronze, is the earliest known dated example and bears the name
of its maker. The inscription at the back of the kursi, or throne, is written in khufic and states
that the astrolabe was made by Nastulus (or Bastulus) and gives the date, which corresponds
to 927/28. The date is rendered in Arabic letters, whose numerical values total 315, signifying
the year in the Islamic calendar in which the astrolabe was made
