Astronomical Ring Dial by Gualterus Arsenius
Record status
Individual type · partial
Period
1572
This astronomical ring dial, dated 1572, was constructed by Gualterus Arsenius in Louvain. The instrument is crafted from gilt brass and measures 262 mm in diameter.
It comprises three hinged circular brass rings: a fixed meridian ring, an equatorial ring perpendicular to the meridian, and a third mobile ring that rotates inside. The meridian ring features a latitude scale ranging from 90 to 0 to 90 degrees. The equatorial ring includes a zodiacal and calendrical scale, as well as markings for 'Umbra recta' and 'Umbra versa'. The mobile meridian ring contains a pair of sighting holes for taking bearings of specific stars.
The instrument is suspended via a swivelling ring attached to a throne, which is mounted on the fixed meridian ring. The object is signed by the maker on the meridian ring with the Latin inscription 'G.A. nepos Gemme Fris Louan fecit anno 1572'.
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
- 1572
- Type
- Flemish astronomical ring dial
- Maker
- Gualterus Arsenius
- Diameter
- 262 mm
- Location
- Louvain
- Material
- Gilt brass
- Place recorded
- Louvain
- Maker / attribution
- Gualterus Arsenius
Design
- Visible features
- • Instrument features a blank throne. • Meridian ring marked with Polus arcticus and Polus antarcticus. • Outer rim and equatorial ring inscribed with names of thirty stars. • Equatorial ring inscribed with 'Aequinoctialis' and 'Aequator'.
- Inscriptions and Markings
- The instrument bears numerous inscriptions detailing its function and origin. The equatorial ring features a combined zodiacal and calendrical scale, along with the text 'Aequinoctialis', 'Aequator', 'Umbra recta', and 'Umbra versa'. The meridian ring includes a signature and date at the bottom, identifying the maker as the nephew of Gemma Frisius. Additionally, both the outer rim and the equatorial ring are decorated with eight-pointed star symbols and the names of thirty distinct stars, including 'Canopus', 'Arcturus', and 'Lyra'.
- Construction and Mechanics
- The instrument is composed of three hinged circular brass rings that allow for various astronomical calculations. The arrangement includes a fixed meridian ring and an equatorial ring set perpendicular to one another. A third, mobile ring rotates within the structure. When not in use, the assembly is designed to be folded flat. Suspension is provided by a swivelling ring connected to a throne, which is fixed to the meridian ring. The meridian ring displays a latitude scale and is inscribed with 'MERIDIANVS', 'Polus arcticus', and 'Polus antarcticus'. The mobile inner ring incorporates a set of adjustable sighting holes for taking stellar bearings.
- Provenance and Documentation
- The object is held by the Museum Boerhaave in Leiden, inventory number 9163. It has been on loan from the Leiden Observatory since 1931. Prior to its formal acquisition, the instrument remained undocumented. The item was rediscovered around 1868 within the attic of the Leiden University Library. Its existence is referenced in scholarly literature concerning 16th-century scientific instruments.
Identification
- Inventory Number
- 9163
- 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: Original flat storage case is no longer present.
- Research required: History prior to the discovery of the instrument in 1868 remains unknown.