Astrolabe of ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari

Maker: ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari

Object Name: Astrolabe

Date: dated A.H. 690/ A.D. 1291

Geography: Made in Yemen

Medium: Brass; cast and hammered, pierced, chased, inlaid with silver

Dimensions: Case (a): Max. W. 7 5/8 in. (19.4 cm)
Diam. 6 1/8 in. (15.6 cm)
D. 1/4 in. (0.6 cm)
Bar with attached nail (b): Max. H. 1 7/8 in. (4.8 cm)
Max. W. 1 1/8 in. (2.9 cm)
L. 5 in. (12.7 cm)
Net (c): Diam. 5 in. (12.7 cm)
Plates (d-g): Diam. 5 in. (12.7 cm)
Pin (h): L. 1 3/4 in. (4.4 cm)
W. 1/2 in. (1.3 cm)

Classification: Metal

Credit Line: Edward C. Moore Collection, Bequest of Edward C. Moore, 1891

Accession Number: 91.1.535a–h


For an object produced during the medieval period, this astrolabe is unusually well documented. Its inscription attributes it to a Rasulid prince, 'Umar ibn Yusuf, a few years before he ascended to the throne (r. 1295–96). 'Umar compiled a number of scientific treatises, including one on the construction of astrolabes, an autographed version of which, preserved in Cairo, contains certifications by his teachers as to his competence as a maker of such devices and a description of this very piece.