13th Century Gilt Copper Astrolabe
Record status
Individual type · partial
Period
13th century
This 13th-century astrolabe is a small instrument measuring 98 mm in diameter, constructed from gilt copper. It is unsigned and features a rete adorned with 23 star indicators formed by silver studs.
The instrument includes a mater housing three latitude plates, two of which are calibrated for latitudes covering 41 to 44 degrees. The third plate contains an incomplete projection of the heavens on one side and a series of traced lines on the reverse. The limb is graduated in 5-degree increments up to 360 degrees. The back displays zodiacal signs, months, and a shadow square labeled 'VMBRA VERSA' and 'VMBRA DIRECTA'.
The alidade features sighting vanes and engraved leaf motifs. The piece originates from the historical scientific collection of the Medici family in Florence and is currently held by the Istituto e Museo di Storia della Scienza.
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
- Type
- French astrolabe
- Diameter
- 98 mm
- Material
- Gilt copper
- Condition
- Structural crack
- Provenance
- Medici collection
- Place recorded
- France
- Star indicators
- 23 silver studs
- Shadow square inscriptions
- VMBRA VERSA, VMBRA DIRECTA
Design
- Visible features
- • The rete is decorated with 23 small silver studs representing stars. • A significant structural crack extends from the edge of the limb towards the center. • Gothic script is used for numbering and naming of zodiacal signs. • The throne incorporates a ring attached to a rotating pivot.
- Back Plate and Condition
- The reverse of the astrolabe is densely engraved with astronomical and calculation scales. This includes a division from 90 to 0 and 0 to 90 degrees, repeated twice, alongside zodiacal signs and month names. A circumferential scale is divided from 1 to 28, beginning from the diameter. Below this, a shadow square is present, featuring the dual inscriptions 'VMBRA VERSA' and 'VMBRA DIRECTA', both repeated twice. Regarding its physical state, a prominent crack is present. It traverses the instrument, originating from the exterior circumference and extending into the limb. The object is currently held in the collection of the Istituto e Museo di Storia della Scienza in Florence, having been part of the Medici family's historical collection of scientific instruments.
- Latitude Plates and Mater
- The mater contains three plates that fit within the instrument's frame. Two of these plates are calibrated for specific latitudes, covering 41-42 degrees and 43-44 degrees. These are associated with the regions of Castille and Provence. The third plate is distinct in that one face features an incomplete projection of the heavens without any latitude marking, while the reverse side contains several traced lines. Interestingly, the inscriptions for the 43 and 44-degree plates are noted to be in non-gothic characters, differing from the primary engravings on the rest of the instrument.
- Construction and Rete Design
- The astrolabe is manufactured from gilt copper, measuring 98 mm in diameter. The central component is the rete, which acts as a star chart and ecliptic ring. It is embellished with 23 silver studs which function as star pointers. The zodiacal signs are identified in Latin using gothic lettering, consistent with the numbering style found on the instrument's limb. The limb itself is systematically divided into 360 degrees, with groupings marked every 5 degrees. The throne at the top of the astrolabe is attached to a rotating pivot, allowing the ring to swivel. The alidade or pointer is equipped with sights at its extremities, with decorative leaf motifs engraved near the central pivot, demonstrating specific attention to detail in its assembly.
Identification
- Inventory Number
- 1107
- 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 provenance attributing the piece to 13th-century France is based on museum categorization rather than a maker's mark or date inscription.
- Research required: The third latitude plate contains non-gothic characters, suggesting potential later modifications or additions to the set.