Astrolabe, inventory 41122
Record status
Individual type · partial
Period
13th century
This 13th-century brass astrolabe (inventory 41122) is catalogued as originating from North Africa. The instrument features a five-lobed throne, an omega-type shackle with animal-head carving, and a simple ring with a square cross-section.
The mater and limb are constructed from two riveted pieces, with a notch on the throne for tympan alignment. The back incorporates a universal projection based on the system developed by Ibn az-Zarqāllu, featuring sets of equatorial and ecliptic coordinates, though the declination scale is omitted. The instrument includes four plates for latitudes 31°0' to 47°0'. The object was bequeathed to the History of Science Museum by T.
G. Barnett in 1935, having been acquired by him around 1925 from 'Ali Hikmet of Kirkuk.
Evidence at a glance
- Linked sources
- 1
- Photograph views
- 1
- Catalogue references
- 0
Counts describe this entry’s documentation, not authenticity, rarity or completeness. Photographs may show one specimen; check each caption and licence.
Technical characteristics
- Date
- 13th century
- Type
- Arabic-inscribed astrolabe, North Africa
- Material
- Brass
- Provenance
- Bequeathed by T. G. Barnett
- Place recorded
- North Africa
- Place of origin
- North Africa
- Rete star count
- 29
- Number of plates
- 4
- Universal projection source
- Ibn az-Zarqāllu
Design
- Visible features
- • Five-lobed throne with simple, undecorated design. • Rete features dagger-style star pointers. • Omega-shaped shackle with carved animal-head terminals. • Rete attached with a pin and horse assembly.
- Provenance and History
- The instrument was acquired by the History of Science Museum in 1935 as part of a bequest from T. G. Barnett, a jeweller and goldsmith based in Birmingham. The collection donated by Barnett was primarily composed of time-telling devices including watches, clocks, and sundials, with this astrolabe being the sole example in the assemblage. Prior to its acquisition by Barnett around 1925, the astrolabe belonged to 'Ali Hikmet of Kirkuk, Iraq.
- Construction and Design
- The astrolabe is manufactured from brass and follows a construction utilizing a five-lobed throne and an integrated base. The mater and limb are assembled from two riveted pieces, and the throne includes a notch to accept tympan tabs, which prevents rotation during use. The ring displays a simple, squared cross-section, and the shackle is of the omega type, with tabs shaped to resemble the heads of animals. The instrument includes four distinct plates, each calibrated for latitudes ranging from 31°0' to 47°0'.
- Universal Projection and Astronomical Features
- The rear of the instrument features an az-Zarqellu universal projection, which integrates both equatorial and ecliptic coordinate systems. The ecliptic is inclined downward to the right and bears the names of zodiacal signs in Kufic script. While the instrument includes a complete set of equatorial coordinates, it provides only an abbreviated set of ecliptic coordinates and omits a declination scale. The rete is engraved with 29 stars, 28 of which are named. These are indicated by dagger-style pointers. The womb, located on the back of the device, contains six scales, including declination, zodiacal signs, a calendar, lunar mansions, and a shadow square. A scale on the limb contains 91 approximately equal divisions marked with characters, the specific function of which remains unverified.
Identification
- Serial number
- 41122
- Inventory number
- 41122
- Source note
- Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Research required: The rule and the pin and horse assembly are considered to be likely replacements.
- Research required: The use of the scale or inscriptions along the edge of the limb is not immediately clear.