Astrolabe signed by 'Abd al-'Ali
Record status
Individual type · partial
Period
early 18th century
This brass astrolabe is identified by the inventory number 37940 and attributed to the maker 'Abd al-'Ali, an individual associated with the Isfahan group of instrument makers during the first decades of the 18th century.
The instrument features a throne of the engraved Indo-Persian type and an omega-shaped shackle. The rete is of the foliate type and exhibits a symmetrical layout that deviates from actual astronomical star positions. The back of the instrument contains 11 scales, including altitude, sine/cosine, and zodiacal signs, which are described as incorrect. The piece includes three plates with latitudes between 32 and 38 degrees and a double-ended alidade featuring non-functional, engraved abdjad numerals.
The astrolabe was presented to the History of Science Museum by J. A. Billmeir in 1957.
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
- early 18th century
- Type
- Arabic-inscribed astrolabe, Iran
- Maker
- 'Abd al-'Ali
- Place
- Persia
- Material
- Brass
- Acquisition
- Presented by J. A. Billmeir in 1957
- Throne style
- Indo-Persian, engraved
- Place recorded
- Persia
- Maker / attribution
- 'Abd al-'Ali
Design
- Visible features
- • The rete features a zoomorphic bird design at the center of the ecliptic. • The limb of the mater is of one-piece construction and lacks tabs or notches. • The back includes an inscription identified as a maker's signature. • The shackle is of the omega type (Ω-shaped).
- Construction and Design
- The astrolabe is constructed of brass and features an engraved Indo-Persian style throne with an integrated base. Attached to the throne is an ornate ring and an omega-shaped shackle. The rete is characterized as a foliate, plain type with a bird figure in the center of the ecliptic. The astronomical layout of the rete is symmetrical, which prevents it from functioning as a accurate map of real star positions. The ecliptic is not graduated, and the positions of the zodiacal signs are displaced by approximately 15 degrees.
- Scales and Inscriptions
- The back of the instrument displays 11 distinct scales, including altitude, sine/cosine, declination, cotangent, zodiacal signs, and lunar mansions. The institution reports that these scales are all inaccurate. Additionally, the instrument contains a signature, translated as 'Abd al-'Ali made this, and an embossed quotation from the Qur'an on the front throne. The double-ended alidade is engraved with abdjad numerals designed to mimic the appearance of scales, though these numerals do not correspond to any recognizable scientific or mathematical scale. The womb of the instrument is engraved with text designed to resemble a gazetteer, but the entries do not represent actual cities or geographic coordinates.
- Provenance and Attribution
- This astrolabe, bearing inventory number 37940, was acquired by the History of Science Museum, Oxford, through a presentation by J. A. Billmeir in 1957. The institution records indicate that Billmeir acquired the object between 1955 and 1957. The astrolabe is associated with the maker 'Abd al-'Ali, who is linked to the Isfahan group of instrument makers from the early 18th century. However, the cataloguing body notes that the piece is potentially an imitation or a forgery, citing its astronomical inaccuracies and the meaningless nature of its inscriptions as indicators of its deviation from genuine scientific instruments of that period.
Identification
- Inventory number
- 37940
- 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 accuracy of the astronomical content and functionality is questioned by the institution.
- Research required: The rete design is described as an impossibility for a functional map of real star positions.