Astrolabe, ca. 1300 (?)
Record status
Individual type · partial
Period
ca. 1300 (?)
This gilt brass astrolabe, inventory number 40829, is attributed to Sicily and dated to approximately 1300. , it features a unique rete design that integrates northern and southern projections of the ecliptic, causing the twelve zodiacal signs to align on a single arc below the center.
Its construction, where the rete's outer edge corresponds to the equator rather than the Tropic of Capricorn, renders the instrument an abstract model rather than a functional representational tool. The object includes a three-lobed throne attached to a one-piece mater and limb. The back displays scales for degrees, unequal hours, and a shadow square. Four star pointers are present on the rete, though they remain unnamed.
The instrument is held together by a rivet featuring a star-shaped head. The piece was presented to the History of Science Museum by Lewis Evans in 1924, having been acquired from a Florence bookseller.
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. 1300 (?)
- Type
- Latin-inscribed astrolabe
- Material
- Gilt brass
- Provenance
- Purchased from Leo S. Olschki, Florence, circa 1901
- Throne type
- Three-lobed
- Place recorded
- Sicily
- Acquisition date
- 1924
- Place of manufacture
- Sicily
Design
- Visible features
- • The rete features a star-shaped rivet head at the center. • The throne is a small, three-lobed tab configuration. • The shadow square is centrally located on the back of the instrument. • The alidade is double-ended and counter-changed.
- Provenance and History
- The instrument was acquired by Lewis Evans from the Florence bookseller Leo S. Olschki circa 1901. It was subsequently presented to the History of Science Museum in 1924. The dating of the instrument has been a subject of analysis, with Evans initially suggesting 1460, while recent studies have proposed an earlier date of approximately 1300. Its physical limitations regarding representation and observation suggest it served purposes outside of standard astronomical utility.
- Design and Construction
- The astrolabe is constructed from gilt brass and is notable for its small scale. The throne is fashioned as a three-lobed tab at the top of the instrument, attached via an integrated base. Both the shackle and the ring are missing from the current configuration. The mater and limb are built as a single-piece construction, with the limb extending beyond the rete. The instrument utilizes a rivet to secure the rete, which is visible on the front as a star-shaped head. The back of the astrolabe incorporates three distinct scale types: a circular degree scale spanning 0 to 90 degrees, two sets of unequal hours, and a shadow square divided every three fingers.
- The Rete and Projection
- The rete design is unusual, combining a southern projection for summer signs and a northern projection for winter signs. This forces the ecliptic to fold back upon itself, resulting in all twelve zodiacal signs occupying the same arc beneath the central horizontal line. Unlike common astrolabes, the rete edge is set to the equator, not the Tropic of Capricorn. The rete holds four star pointers, all of which are foliate in style but currently unnamed. Due to the unconventional arrangement of the projections, the user must distinguish between northern and southern readings, a process complicated by the lack of star identification.
Identification
- Inventory number
- 40829
- 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 dating of circa 1300 is speculative, with historical debate between this and an alternative proposal of circa 1460.
- Research required: The instrument's actual astronomical utility is described as limited due to its abstract design and small size.