Astrolabe by Ḥasan ibn ‘Alī
Record status
Individual type · partial
Period
1282/3
This astrolabe, identified by inventory number 49861, is a brass instrument attributed to the maker Ḥasan ibn ‘Alī, dated 1282/3, and manufactured in Cairo. The object features a broad Indo-Persian type throne attached to an integrated base, with a silver omega-type shackle.
The instrument is characterized by a single surviving plate, referred to as the womb on the front side, which is engraved with sixteen concentric circles and retains silver fish ornaments held by rivets. It includes various astronomical scales, including altitude and sine/cosine, alongside tables for determining the degree of the sun and Coptic months. The instrument was acquired by the History of Science Museum, University of Oxford, following its presentation by Lewis Evans in 1924, who had previously purchased the item in London around 1880.
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
- 1282/3
- Type
- Arabic-inscribed astrolabe, Near East
- Maker
- Ḥasan ibn ‘Alī
- Location
- Cairo
- Material
- Brass
- Provenance
- Evans bought it in London about 1880
- Acquisition
- Presented by Lewis Evans in 1924
- Place recorded
- Cairo
- Maker / attribution
- Ḥasan ibn ‘Alī
Design
- Visible features
- • Silvered surface on the back of the plate exhibiting significant wear • Omega-shaped silver shackle featuring a small decorative square • Silver fish ornaments secured by rivets on the front plate • Engraved concentric circles on the front face
- Construction and Design
- The astrolabe is constructed primarily from brass, featuring a distinctively broad, Indo-Persian style throne that is attached to an integrated base. The suspension mechanism consists of a silver shackle formed in an omega shape, which incorporates a small decorative square and additional ornament within its band. The front of the instrument, or the womb, is comprised of a single surviving plate that features sixteen concentric circles engraved into its surface. Five holes are spaced around the edge of this plate; while some remain empty, two currently accommodate silver fish ornaments affixed by rivets, which may have served a functional or decorative purpose in relation to the original limb assembly.
- Provenance and Documentation
- The object is catalogued under inventory number 49861 in the History of Science Museum at the University of Oxford. The accession record indicates it was presented to the museum by Lewis Evans in 1924. Evans had previously obtained the instrument in London approximately in 1880, during the early development of his private collection. The documentation for the astrolabe is maintained by the museum's catalogue, which categorizes it as a 13th-century instrument from Cairo. Certain inscriptions located above the left-hand table and within the sine graphs remain recorded as pending interpretation.
- Astronomical Scales and Tables
- The back of the plate contains extensive astronomical data, including four distinct scales covering altitude, sine/cosine, and cotangent measurements. These scales are arranged in circular, concentric patterns, with the altitude scales occupying the upper quadrants and the cotangent scale situated in the lower right quadrant. In addition to these mathematical scales, the back surface contains two tables. These tables are designed for specific astronomical calculations, including the determination of the degree of the sun and a listing of Coptic months. The original surface was silvered, though the report notes that this finish is now significantly abraded across the surface.
Identification
- Inventory Number
- 49861
- 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 exact original configuration of the limb rivets remains uncertain
- Research required: The extent of silvering loss on the back is ongoing
- Research required: The precise contents of certain inscriptions are marked as pending