Islamic globe. Astronomical details on the sphere include stars, but no constellations; a total of 41 stars are labelled. The ecliptic longitudes of a number of stars have been determined. By comparing these values with those in the Ptolemaic catalogue for AD 137, and using the Arabic rate of precession, the epoch of the stars can be calculated as 1615, with an uncertainty of 18 years. For full details about the cartography and construction of this globe please refer to the related publication.