Brass Astrolabe by Khalīl Muḥammad ibn Ḥasan ‘Alī
Record status
Individual type · partial
Period
ca. 1700
This brass astrolabe, attributed to the maker Khalīl Muḥammad ibn Ḥasan ‘Alī and dated to approximately 1700, originated in Iṣfahān. The instrument features a one-piece mater and limb construction with an integrated tab for plate alignment.
It is equipped with an Indo-Persian engraved throne, a simple round-section ring, and an omega-type shackle. The rete is of the foliate type, incorporating 28 stars identified by foliate pointers and labeled with the zodiacal signs in the original script. The back of the instrument displays 16 diverse scales, including altitude, azimuth of Qibla, sine/cosine, cotangent, and a shadow square. Four plates are included, designed for latitudes ranging from 22°0' to 38°0'.
The instrument was presented to the History of Science Museum, Oxford, by J. A. Billmeir in 1957, having been acquired from the collection of Henri Michel of Brussels.
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
- ca. 1700
- Type
- Persian-inscribed astrolabe
- Maker
- Khalīl Muḥammad ibn Ḥasan ‘Alī
- Origin
- Iṣfahān
- Plates
- 4
- Material
- Brass
- Provenance
- Presented by J. A. Billmeir in 1957, formerly from Henri Michel collection
- Rete Stars
- 28
- Place recorded
- Iṣfahān
- Maker / attribution
- Khalīl Muḥammad ibn Ḥasan ‘Alī
Design
- Visible features
- • The throne features engraved Indo-Persian style decoration. • The womb contains a detailed gazetteer listing the coordinates for 46 cities. • The back includes complex divisions for lunar mansions and triplicities.
- Scales and Gazetteer
- The instrument’s back is dense with mathematical information, containing 16 distinct scales arranged in concentric and quadrant formats. These include standard altitude scales, trigonometric functions such as sine, cosine, and cotangent, as well as astrological data such as zodiacal signs, faces, lunar mansions, and triplicities. A shadow square is present in the lower quadrants to assist in surveying calculations. The womb of the astrolabe houses a comprehensive gazetteer. This grid provides geographical coordinates including longitude, latitude, Inhiraf, and Jihat for 46 cities, ranging from Isfahan and Hamadan to more distant locations like Mecca, Medina, and Kashmir.
- Provenance and History
- This astrolabe entered the collection of the History of Science Museum in Oxford in 1957, gifted by J. A. Billmeir. The object's recorded history prior to this donation indicates that Billmeir purchased the piece around 1950 as part of the private collection of Henri Michel of Brussels. The instrument retains its original double-ended alidade and is secured by a pin and horse mechanism. It is listed in the museum's catalogue under the inventory number 50987, referencing its specific manufacture in Iṣfahān circa 1700.
- Construction and Design
- The astrolabe is constructed primarily of brass and exhibits a one-piece design for the mater and limb. An integrated tab located at the bottom of the limb serves to prevent the internal plates from rotating during use. The throne is of the Indo-Persian engraved type, secured by an integrated base. The instrument is fitted with a simple round-section ring and an omega-shaped shackle, facilitating its suspension. The rete, identified as a foliate, single-knob type, contains 28 stars, each marked with a foliate pointer. The ecliptic scale is divided into 30-degree segments, and the zodiacal signs are engraved in their traditional order.
Identification
- Inventory Number
- 50987
- 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 modern star name for some listed entries remains unverified.
- Research required: The precise original intended purpose for certain shadow square settings is not explicitly documented in the provided source.