Brass Astrolabe, ca. 1260
Record status
Individual type · partial
Period
ca. 1260
This brass astrolabe (inventory number 43504) is dated to circa 1260 and is attributed to a possible Spanish origin. The instrument features a simple throne with a filleted edge, an omega-shaped shackle, and a mater with an integrated limb of two-piece soldered construction.
It is equipped with five plates covering latitudes from 12° to 48°. The rete, of an indicator-line type, displays 20 star positions marked with dagger pointers and a labeled zodiac. The back of the instrument contains four distinct scales: a degree scale, zodiacal signs, a calendar, and a shadow square. The alidade is double-ended and counter-changed, although one of its two sighting vanes is broken. The device is currently held in the collection of the History of Science Museum in Oxford, having been presented by Lewis Evans in 1924, who reportedly purchased it in Venice in 1899.
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. 1260
- Type
- Latin-inscribed astrolabe
- Material
- Brass
- Provenance
- Presented by Lewis Evans in 1924
- Star count
- 20
- Place recorded
- Spain (?)
- Purchased date
- 1899
- Place of origin
- Spain (?)
- Number of plates
- 5
Design
- Visible features
- • Omega-shaped shackle • Dagger-style star pointers on the rete • One sighting vane missing from the alidade • Filleted edge on the throne
- Provenance and History
- The astrolabe was accessioned by the History of Science Museum in 1924 following its presentation by Lewis Evans. Historical records indicate that Evans acquired the piece in Venice in 1899. Examination of the object suggests historical intervention. It is believed that an owner circa 1400 may have re-engraved certain elements of the instrument, indicating a long period of use or maintenance after its initial manufacture in the 13th century.
- Scales and Astronomical Layout
- The back of the astrolabe incorporates four distinct functional scales for calculation. These consist of a degree scale ranging from 0 to 90 degrees, a zodiacal scale divided into 30-degree segments, a calendar scale representing the days of the year, and a shadow square measuring 0 to 12 fingers. The limb of the mater features a circular, concentric degree scale ranging from 0 to 360 degrees, marked at five-degree intervals. On the rete, the ecliptic is defined with a scale ranging from 0 to 30 degrees, while a degree scale corresponds to the equator of the tropic of Capricorn. The zodiacal signs are inscribed in a sequence beginning with Aries and ending with Pisces.
- Structural Composition and Components
- The instrument is constructed from brass, featuring a two-piece mater and limb joined via soldered construction. The throne is categorized as a simple type with a filleted edge and is paired with an omega-shaped shackle. The instrument utilizes a pin and horse assembly to secure the rete to the central axis. The rete follows an indicator-line or simple style, populated with 20 star locations, each marked by a dagger pointer. There are five accompanying plates provided for the instrument, accommodating latitudes ranging from 12°0' to 48°0'. Both the pointer and the alidade are described as original examples, with both being counter-changed in their design. The alidade is rigid and double-ended, though its current condition is incomplete due to a broken sighting vane.
Identification
- Inventory number
- 43504
- 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 remains uncertain, noted as Spain (?)
- Research required: The extent to which 14th-century re-engraving affected original components is not fully specified