Astrolabe by Khalīl Muḥammad ibn Ḥasan ‘Alī

Technical characteristics

Type

Arabic-inscribed astrolabe

Maker

Khalīl Muḥammad ibn Ḥasan ‘Alī

Material

Brass

Acquisition

Presented by J. A. Billmeir in 1957

Rete status

Replacement

Place recorded

Iṣfahān

Maker's signature

‘Abd al-Aʾimmah

Gazetteer capacity

46 cities

Maker / attribution

Khalīl Muḥammad ibn Ḥasan ‘Alī

Design

Visible features

• The throne is pierced with four arabesque designs. • The rete features 19 star pointers without names. • The horse-shaped pin includes an unusual duck-head detail. • The alidade is a double-ended replacement without scales.

Construction and Main Body

The astrolabe is primarily constructed of brass, featuring a mater and limb formed from a single-piece construction. The instrument includes a pierced, Indo-Persian style throne that is attached to an integrated base. This throne is decorated with extensive embossing and includes an inscription quoting a Qur'anic verse. The suspension mechanism consists of a squared cross-section ring and an omega-type shackle, which is secured by decorative tabs and a pin. The limb is inscribed with a degree scale spanning 0 to 360 degrees, marked every five degrees. The interior womb contains a comprehensive gazetteer listing the coordinates for 46 cities, providing longitudes and latitudes for locations spanning from Mecca to Kabul. The quality of the instrument's primary components is described as finished and elegant, contrasting with later replacement parts.

Back Scales and Inscriptions

The back of the astrolabe is highly detailed, containing 17 distinct scales. These include traditional navigational and mathematical scales such as altitude, azimuth of Qibla, sine/cosine, and cotangent scales measured in feet and fingers. The back also features astrological information, such as zodiacal signs, terms, faces, and lunar mansions. The back bears two primary inscriptions. One is the maker's signature, crediting the work to ‘Abd al-Aʾimmah, and a philosophical inscription at the bottom edge which reflects on the transitory nature of existence. These are presented in cartouches, highlighting the decorative and intellectual emphasis of the instrument’s design.

Replacements and Rete Details

The current rete is a later replacement, distinguished by its crude workmanship and lack of naming for the 19 star pointers. The rete is held in place by a pin and horse assembly. Like the rete, the double-ended alidade is a later addition and contains no markings or scales, bearing little resemblance to the refined quality seen on the rest of the original instrument.

Identification

Reference

35313

Inventory number

35313

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.