Astronomical Ring Dial, Late 16th century
Record status
Individual type · partial
Period
Late 16th century
This astronomical ring dial, measuring 70 mm in diameter, is constructed from gilt brass and is unsigned. It comprises three rings: a meridian ring, an equatorial ring, and a third ring pivoted to the polar points, which is fitted with an internal sliding ring featuring a pair of sights.
The meridian ring features a degree scale, while the equatorial ring contains a 12-hour scale and an internal calendrical scale. The sliding ring is equipped with indices that move over degree and zodiacal scales to adjust for solar declination, and includes an ecliptical scale with star positions. The exterior of the third ring displays abbreviated names and numbers for 25 stars. The instrument is adjustable for latitude using a swivelling ring attached to a decorated arc on the outer ring.
It was bequeathed to the British Museum by Octavius Morgan in 1888.
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
- Flemish astronomical ring dial
- Diameter
- 70 mm
- Material
- Gilt brass
- Provenience
- Bequeathed by Octavius Morgan
- Equinox dates
- 15 March and 10 September
- Place recorded
- Flemish
- Maker attribution
- Flemish maker
- Latitude adjustment
- 42 1/2 degrees to 59 degrees
- Maker / attribution
- Unknown (Attributed to Flemish)
- Registration number
- MLA 1888,12-1.316
Design
- Visible features
- • Three-ring construction • Gilt brass finish • Suspension ring attached to a decorated arc • Internal sights and sliding ring
- Structural Composition
- The instrument is composed of three primary rings, including a meridian ring, an equatorial ring, and a polar ring. It features a mechanism for latitude adjustment, where an arc attached to the outer meridian ring allows movement between 42 1/2 and 59 degrees along a degree scale. A suspension ring is fixed to the decorated arc to hold the instrument. When the rings are unfolded, the equatorial ring is perpendicular to the meridian ring. A third ring, pivoted to the polar points of the meridian, houses an internal sliding ring equipped with sights.
- Provenance and Documentation
- The item was acquired by the British Museum through the bequest of Octavius Morgan in 1888. It is currently held in the Department of Medieval and Later Antiquities. The instrument is documented in a published catalogue of scientific instruments where it is identified by its specific inventory number and attributed to a Flemish maker working near 1600.
- Scales and Astronomical Features
- The meridian ring includes a double degree scale marked from 0 to 90. The equatorial ring incorporates both 12-hour scales and an internal calendrical scale identifying months by their initials. Zodiacal symbols are engraved on the exterior of the equatorial ring. The third ring is designed for solar observations using sights that align with zodiacal and degree scales. Its sliding ring features an ecliptical scale and identifies the positions of 25 stars, listed by name and number on the exterior of the ring.
Identification
- 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: Unsigned and undated, maker is attributed based on style
- Research required: Exact date of manufacture is approximate