Polyhedral Dial, circa 1525
Record status
Individual type · partial
Period
circa 1525
This polyhedral sundial, standing 100 mm tall and constructed from gilt brass, is a complex timekeeping instrument designed with nine distinct dial faces. Based on an octagonal geometry, it incorporates an array of horizontal, polar, equinoctial, and vertical dials, all configured for a latitude of 52 degrees.
The top surface features a horizontal dial and a recess intended for a compass, though the magnetic needle and cover are missing. The structure is supported by a four-sided base adorned with armorial engravings associated with Cardinal Wolsey, including the arms of York Minster and a cardinal's hat. While unsigned, the instrument is attributed to the German mathematician Nicolaus Kratzer, who served as astronomer to Henry VIII and was associated with Corpus Christi College, Oxford.
The object is held in the collection of the Museum of the History of Science, 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
- Type
- English polyhedral dial
- Height
- 100 mm
- Latitude
- 52 degrees north
- Material
- Gilt brass
- Provenance
- Cardinal Wolsey
- Place recorded
- England
- Number of Dials
- 9
- Maker / attribution
- Attributed to Nicolaus Kratzer
Design
- Visible features
- • Engraved cardinal's hat on the base • Projection of the celestial sphere marked with star patterns on octagonal faces • Triangular gnomons fixed to several faces • Gilt brass construction
- Geometry and Dial Configuration
- The instrument derives its complex form from an octagonal solid, which serves as a platform for nine individual sundials. The faces are oriented to allow for timekeeping on multiple planes as they receive sunlight. The top surface hosts a horizontal dial labeled for hours 6 to 12 to 6. Integrated into this section is a central circular recess, originally designed to accommodate a magnetic compass for orientation. The remaining faces are dedicated to specific astronomical representations. These include polar dials set at right angles to the equatorial plane, as well as superior and inferior equinoctial dials positioned parallel to the equatorial plane. Vertical north and south dials are situated on the rectangular sides, while the two large octagonal faces feature elaborate projections of the celestial sphere, detailing the horizon, tropics, and various circles, finished with dotted star markings.
- Material and Armorial Decoration
- The instrument is fabricated from gilt brass and stands at a height of 100 mm. The base is structured as a four-sided pedestal that provides both physical stability and a medium for heraldic display. The engravings on the base serve to identify the patron for whom the instrument was manufactured. The base features the coat of arms belonging to Cardinal Wolsey and the arms of York Minster. Furthermore, two sides of the base are decorated with engravings of a cardinal's hat. These features provide a direct link to the instrument's original ownership and the high-ranking status of the patron in early 16th-century England.
- Attribution and Historical Context
- Although the object bears no signature, historical scholarship attributes its creation to the German mathematician Nicolaus Kratzer. Kratzer moved to England around 1518, where he eventually took the position of astronomer to Henry VIII. His academic standing was further solidified through his role at Corpus Christi College, Oxford, and his lectureship founded by Cardinal Wolsey. The reliance on complex polyhedral geometry illustrates the advanced level of instrument design practiced by Kratzer during his time in England in the early 16th century.
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: Magnetic needle and glazed compass cover are absent
- Research required: Attribution to Nicolaus Kratzer is based on scholarly opinion rather than a signature