Astrolabe by Adrianus Descrolieres
Record status
Individual type · partial
Period
1580
This gilt brass astrolabe, measuring 271 mm in diameter, was made in Paris by Adrianus Descrolieres and dated 1580. The instrument features a rete with tulip-shaped elements, and a throne designed as two reclining satyrs flanking a central shield.
The mater rim is marked with an equal 24-hour scale and an altitude scale, with the interior containing a quadratum nauticum. The device includes three plates engraved with coordinates for varying latitudes, the Horizon rectus, and the Horizon obliquus. The back of the astrolabe displays a universal projection attributed to Gemma Frisius. Star names, planetary temperaments, and magnitudes are engraved throughout the instrument.
The front is fitted with an alidade marked with sun rise and set times, alongside solar declination scales. The object was formerly part of the Spitzer collection and is held by the British Museum, registered as MLA 1893,6-16.1.
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
- 1580
- Type
- French astrolabe
- Maker
- Adrianus Descrolieres
- Diameter
- 271 mm
- Material
- Gilt brass
- Provenance
- Spitzer collection
- Place recorded
- France
- Maker / attribution
- Adrianus Descrolieres
Design
- Rete and Plates
- The rete follows the Arsenius pattern, incorporating 43 identified stars. Each star is annotated with its magnitude and corresponding planetary temperament, often utilizing symbols in place of zodiacal names. The ecliptic is marked with zodiacal signs, months, and single-degree graduations. Three plates provide coverage for various latitudes, marked for elevations ranging from 39 to 51 degrees. These plates feature circles for the equator and tropics, azimuths, and almucantars. Plate 3b contains a Horizontale catholicum, providing a shadow scale and an hour diagram for converting equal to unequal hours, represented by segments of vertical hyperbolic spirals.
- Visible features
- • The compass needle is missing from the inset shield. • The instrument is engraved with the signature and date on the base ring. • The rete includes star names and symbols for planetary temperaments.
- Construction and Layout
- The astrolabe is constructed of gilt brass and measures 271 mm in diameter. The rim of the mater is riveted to the backplate and features an external 24-hour scale, with an internal 360-degree altitude scale graduated for observation. The interior of the mater is engraved with a quadratum nauticum, detailing wind names in three distinct bands covering cardinal and intermediate directions. The throne is fixed to the rim with two screws and consists of a base ring featuring two reclining satyrs. This supports a central shield-shaped suspension piece originally intended to house a compass, though the needle is now absent. Additional components include a rule and an alidade fitted to the front, which bears specific markings for solar declination and sunrise and sunset hours.
- Provenance and Literature
- The instrument was acquired by the British Museum in 1893, having previously been part of the Spitzer collection. It is catalogued as MLA 1893,6-16.1 in the Department of Medieval and Later Antiquities. Detailed documentation of this specific astrolabe appears in F. A. B. Ward's 1981 publication regarding the British Museum's collection of European scientific instruments, where it is listed as item number 337.
Identification
- Inventory Number
- MLA 1893,6-16.1
- 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 magnetic deviation of the missing compass is listed as approximately 12 degrees east.
- Research required: The source notes a reengraving on the Corona Septentrionalis.