Brass astrolabe, North Africa
Record status
Individual type · partial
Period
early 18th century
This planispheric astrolabe, inventory number 34314, is a brass instrument of North African origin dating to the early 18th century. The instrument features a simple brass throne with an integrated base and an eye-bolt type shackle.
Its mater and limb are constructed from two pieces through soldering and riveting; the limb exhibits a repair, potentially addressing a previous fracture or deficiency. The astrolabe includes four plates covering latitudes between 21°0' and 36°0'. The back of the instrument displays six distinct scales, including those for altitude, zodiacal signs, calendar, unequal hours, and a shadow square. The back bears an inscription dedicating the device as a bequest to the Grand Mosque in Tangiers.
The present double-ended alidade is a replacement and lacks scales or decoration. The object 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, North Africa
- Material
- Brass
- Inscription
- Arabic inscription dedicating the astrolabe to the Grand Mosque of Tangiers
- Construction
- Two-piece soldered and riveted mater and limb
- Place recorded
- North Africa
- Place of origin
- North Africa
Design
- Visible features
- • Simple brass throne with integrated base • Replacement double-ended alidade • Visible repair on the limb
- Scales and Inscriptions
- The back of the astrolabe is engraved with six scales: altitude, zodiacal signs, calendar, unequal hours, and a shadow square. The degree scale on the limb spans 0 to 360 degrees, marked every five degrees. The shadow square scales are divided into twelve units, or fingers, and are placed on the vertical and bottom faces of the square. The back also features an inscription in Arabic, translated as: "Praise be to God. This astrolabe was given as a bequest to the Grand Mosque of the port of Tangiers, may God elevate it with His grace. Amen."
- Provenance and Condition
- The astrolabe was acquired by J. A. Billmeir as part of the collection of Henri Michel of Brussels, purchased circa 1950. It was subsequently donated to the History of Science Museum in Oxford in 1957. Regarding its physical condition, the limb has undergone a repair, which may have been necessitated by a break or other structural deficiency. The replacement of the alidade indicates that the instrument is no longer in its original, complete state.
- Instrument Construction and Components
- The astrolabe consists of a mater and limb constructed from two pieces of brass, joined by soldering and riveting. The instrument includes a simple-type throne with an integrated base and an eye-bolt type shackle assembly that attaches to a fish-hook style ring. The notch required for positioning the tympans is situated at the throne. The device includes four plates with latitude ranges from 21°0' to 36°0'. The current double-ended alidade is a replacement and features no scales or decorative elements, distinguishing it from the primary body of the instrument.
Identification
- Reference
- 34314
- Accession number
- 1957-84/1
- Inventory number
- 34314
- 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 origin of the repair to the limb is not confirmed
- Research required: The donor of the bequest mentioned in the inscription remains unidentified