Astrolabe by ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari, Yemen, 1290–1292 — view 1 of 4
View 1 of 4 · Image: The Metropolitan Museum of Art · original image source

Instruments · Astrolabe

Astrolabe by ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari, Yemen, 1290–1292

DocumentedDocumented from the holding institution's catalogue record.
Date
1290–1292
Country of origin
Yemen
Place
Yemen
Object type
Astrolabe
Materials / technique
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)
Accession / object no.
91.1.535a–h
Credit line
Edward C. Moore Collection, Bequest of Edward C. Moore, 1891
Catalogue title (original)
Astrolabe of ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari

View the source record ↗

Record summary

Held and catalogued by The Metropolitan Museum of Art, New York (object number 91.1.535a–h), this is an astrolabe by ‘Umar ibn Yusuf ibn ‘Umar ibn ‘Ali ibn Rasul al-Muzaffari, made in Yemen, dated 1290–1292. The Atlas places it in the Medieval Period period (500 – 1400) of its Instruments collection. Materials and techniques recorded by the source: Brass; cast and hammered, pierced, chased, inlaid with silver. Recorded 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). The record is illustrated with 4 photographs.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

The source record does not include a narrative description. The structured fields above are reproduced from it.

Historical context

Medieval Period (500 – 1400)

Su Song's astronomical tower in Song China, al-Jazari's automata, and the first European weight-driven verge clocks.

Astronomers in the Islamic world refined the astrolabe, quadrants and sundials for prayer times and astronomy; through al-Andalus these instruments reached Latin Europe, where they were taught at universities.

Read the period in the timelineMore instruments from this periodEarlier: Classical Antiquity

Atlas type guide

Astrolabes, quadrants and astronomical compendia

The planispheric astrolabe is a two-dimensional model of the sky. A pierced rotating star map (the rete) turns over a plate engraved for a particular latitude; by aligning a star or the sun with its observed altitude, the user can read the time of day or night, the time of sunrise and sunset, and solve many other astronomical problems. Developed in the Hellenistic world and refined by astronomers in the Islamic world from the eighth century, it reached Latin Europe through al-Andalus.

Quadrants, compendia, armillary spheres and later orreries belong to the same family of instruments that model the heavens. They were teaching tools, status objects and practical time-finders. Many surviving examples are signed and dated, which makes them important evidence for the history of instrument-making workshops in Baghdad, Isfahan, Lahore, Toledo, Louvain, Nuremberg, London and elsewhere.

What to look for

  • The latitudes engraved on the plates — they show which cities the instrument was made for.
  • The script and calendar used: Arabic or Persian inscriptions, abjad numerals, Hebrew or Latin text indicate tradition and region.
  • The design of the rete: the number of named stars and the style of the star pointers changes by region and period.
  • Shadow squares, unequal-hour lines and zodiac scales on the back (dorsum).
  • Signatures, dedications and dates, often hidden on the throne (kursi) or the back.

Dating clues

  • Signed and dated astrolabes allow precise dating; undated ones are attributed by star positions on the rete, which shift slowly through precession.
  • Gothic-style retes with tracery are typical of European instruments of the fourteenth and fifteenth centuries.
  • Printed paper astrolabes and planispheres became common from the sixteenth century onward.

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.

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