Astronomical Ring Dial by Gualterus Arsenius, 1567
Record status
Individual type · partial
Period
1567
This astronomical ring dial is a brass instrument measuring 111 mm in diameter. It is signed by Gualterus Arsenius and dated 1567 at Louvain. The construction follows the format described by Gemma Frisius, featuring folding rings for the meridian, equator, and declination, along with a sliding ring for the sights.
The meridian ring includes a latitude scale, while the equatorial ring displays hours, a shadow square, and a zodiacal calendar. The declination ring features a zodiac scale, a declination scale, and star markings. A sliding ring, which acts as a later replacement, provides two sights with pinholes and additional astronomical scales. The instrument is held by the Museum of the History of Science, Oxford, and possesses a provenance involving the Michel and Billmeir collections.
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
- 1567
- Type
- Flemish astronomical ring dial
- Maker
- Gualterus Arsenius
- Material
- Brass
- Provenance
- Michel and Billmeir collections
- Inscription
- Nepos Gemmae Frisij Louanij fecit 1567
- Place recorded
- Belgium
- Maker / attribution
- Gualterus Arsenius
Design
- Visible features
- • Meridian ring features a latitude scale numbered by 10 • Equatorial ring includes both a shadow square and a zodiacal calendar • Sliding ring carries two sights with pinholes
- Astronomical Scales
- The equatorial ring provides multiple functions on its two faces, including a semicircle of hours divided into 20-minute and 4-minute intervals, and a shadow square labeled 'VMBRA RECTA' and 'VMBRA VERSA'. It also supports a zodiacal calendar located on the inner rim, while the zodiac signs are engraved on the outer rim. The declination ring carries scales for declination and a further circular scale of hours. The outer rim of this ring marks the declination of 14 specific stars, which is also reflected on the innermost sliding ring. This ring, used for sighting, contains two pinhole sights.
- Signatures and History
- The instrument is signed by Gualterus Arsenius, who identifies himself as the nephew of Gemma Frisius. The signature and date are engraved on the meridian ring, confirming its origin in Louvain in 1567. The instrument has been held in at least two notable collections: the Michel Collection and the Billmeir collection, before entering the holdings of the Museum of the History of Science in Oxford. The source notes that the inner sliding ring is a later addition based on its distinct engraving style.
- Construction and Design
- The instrument is constructed from brass and measures 111 mm in diameter. It follows the format established by Gemma Frisius, utilizing a series of folding rings to perform astronomical calculations. The frame consists of a meridian ring, an equatorial ring, and a declination ring. The meridian ring incorporates a latitude scale marked from 0 to 90 degrees. The suspension mechanism allows for adjustments in latitude via slots provided in the suspension plate. The outer rim includes markings for the arctic and antarctic poles and provisions for mounting the suspension hardware.
Identification
- Inventory Number
- 48126
- 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 innermost sliding ring is identified as a later replacement based on engraving style
- Research required: The exact nature of the zodiac divisions on the sliding ring is queried by a question mark in the source