Brass Astrolabe with Universal Projection
Record status
Individual type · partial
Period
ca. 1400
This brass astrolabe, designated by inventory number 52869, is attributed to Europe and dated to circa 1400. It is described as a rare western-made example of an astrolabe featuring a Saphea Azarchelis universal projection, which enables use in any latitude.
The instrument is constructed from two soldered and riveted pieces for the mater and limb. It includes a rete with twenty-three stars marked with flamant pointers and a toothed Tropic of Capricorn. The instrument's throne is of the simple type, integrated with the base, and features an omega-type shackle. The back of the instrument displays five scales—degree, zodiacal signs, calendar, unequal hours, and a shadow square—engraved in Roman capitals, while the rete and womb are engraved in Lombardic capital script.
Acquired in 1957 via a gift from J. A. Billmeir, the instrument is held at the History of Science Museum in Oxford.
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. 1400
- Type
- Latin-inscribed astrolabe
- Material
- Brass
- Provenance
- Presented by J. A. Billmeir in 1957
- Star Count
- 23
- Place recorded
- Europe
- Projection Type
- Saphea Azarchelis
- Engraving Script
- Lombardic capital and Roman capital
Design
- Visible features
- • The rete features a distinct toothed Tropic of Capricorn. • The back contains a shadow square divided into twelve segments. • The rete is secured by a nut and bolt mechanism that appears as a later replacement. • The inscription script differs between the back and the main body.
- Engraving and Scales
- The astrolabe exhibits two distinct engraving styles. The rete and the womb are inscribed in a Lombardic capital script, whereas the back of the instrument utilizes Roman capitals. The source indicates that the script on the back suggests it was engraved at a later date than the other components. The back surface contains five functional scales: degree, zodiacal signs, calendar, unequal hours, and a shadow square, the latter being a box-type configuration in the lower two quadrants.
- Provenance and History
- This instrument is part of the History of Science Museum's collection in Oxford, having been presented by J. A. Billmeir in 1957. The astrolabe is identified by the accession number 1957-84/175A, with records indicating Billmeir acquired the object during the period of 1955 to 1957. The projection type is identified as the Saphea Azarchelis, a system originating in eleventh-century Toledo.
- Construction and Design
- The astrolabe is manufactured from brass, featuring a two-piece soldered and riveted mater and limb assembly. The throne is a simple, integrated tab design supporting an omega-shaped shackle, which connects to a squared cross-section suspension ring. The instrument includes two plates calibrated for latitudes ranging between 42° and 51°. The rete incorporates an indicator-line design holding twenty-three stars with flamant pointers and a specific, toothed Tropic of Capricorn edge.
Identification
- Reference
- 52869
- Inventory Number
- 52869
- 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 within Europe remains unverified.
- Research required: The threaded pin and nut are suggested as later additions.