Brass Astrolabe by Aḥmad and Muḥammad
Record status
Individual type · partial
Period
984/5 or 1003/4 (A.H. 374 or 394)
This early Persian brass astrolabe, identified as inventory number 33767, is attributed to Aḥmad and Muḥammad, sons of Ibrāhīm, and dated to either 984/5 or 1003/4 (A.H.
374 or 394). The instrument features an Indo-Persian, pierced-type throne with an integrated base and an omega-style shackle. Constructed in two pieces with soldered mater and limb, it includes three plates with latitudes from 30° to 37°. The back displays five scales including altitude, zodiacal signs, terms, and faces, featuring distinct planetary symbols derived from Greek origins rather than traditional letters. The instrument is equipped with a double-ended alidade and a simple indicator-line rete containing 38 stars.
The piece was acquired by the History of Science Museum in 1924, following its presentation by Lewis Evans, who purchased it in 1919.
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
- A.H. 374 or 394
- Type
- Arabic-inscribed astrolabe
- Makers
- Aḥmad and Muḥammad, sons of Ibrāhīm
- Material
- Brass
- Provenance
- Presented by Lewis Evans in 1924
- Star count
- 38
- Inscription
- Maker's signature on the back
- Place recorded
- Iṣfahān
- Maker / attribution
- Aḥmad and Muḥammad, sons of Ibrāhīm
Design
- Visible features
- • Pierced throne of Indo-Persian type • Planetary symbols on the back plate based on Greek characters • Separation of the limb from the back plate • Zodiacal labels on the rete in Arabic script
- Provenance and History
- The astrolabe was presented to the History of Science Museum by Lewis Evans in 1924. Records indicate that Evans acquired the instrument from Professor Y. Daweed, through the London dealer Percy Webster, in 1919. Some elements of the device suggest modifications over time. Specifically, the style of engraving found on the womb implies that the gazetteer may be a later addition to the instrument. Current research into the device continues to compare its table symbols with those of other catalogued astrolabes.
- Construction and Design
- The astrolabe is crafted from brass and features a two-piece soldered construction comprising the mater and the limb. A pierced throne of the Indo-Persian type is attached to an integrated base, supporting a squared cross-section ring and an omega-type shackle. The instrument is designed with three plates, offering latitudes ranging from 30° to 37°. The rete, of the simple indicator-line type, is noted to be in a state of advanced corrosion. It includes a total of 38 star pointers. An alidade, described as double-ended and original to the piece, is provided for observations. The plates are secured within the mater by a post located on the meridian line near the bottom of the instrument.
- Inscriptions and Planetary Tables
- The back of the instrument contains five scales: altitude, the Dastūr circle, zodiacal signs, terms, and faces. An inscription across the middle of the back provides the signature of the makers, Aḥmad and Muḥammad, sons of Ibrāhīm, and identifies the place of origin as Isfahan. A distinguishing feature of the instrument is the arrangement of tables for astrological terms and faces, which occupy three-quarters of the back. These tables utilize specific planetary symbols derived from Greek prototypes rather than alphabetic shorthand. The zodiacal signs on the rete are inscribed in Arabic, and the degree scales are applied to the limb in 5-degree increments.
Identification
- Reference
- 33767
- Inventory Number
- 33767
- 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 date of manufacture is uncertain between the two cited Hijri years
- Research required: The gazetteer on the womb may be a later addition to the original instrument