Nocturnal and Sundial by Michiel Coignet
Record status
Individual type · partial
Period
1598
This brass instrument, 108 mm in diameter, is signed by the mathematician and instrument maker Michiel Coignet and dated 1598. It is a dual-purpose tool featuring a nocturnal on one side and an 'organum Ptolemai' altitude sundial on the reverse.
The nocturnal base-plate contains latitude correction scales, a zodiacal calendar, and a solar declination scale. Above this, volvelle plates facilitate the calculation of hours and the date of Easter, which is marked 'Epacte Anno. 98'. The index arm is engraved with 'Quadrang. vrse minoris'. The sundial side features a Rojas projection of the celestial sphere, set using a latitude scale and polar index points. The handle is engraved with various city names and their latitudes.
The object was acquired as part of the Lewis Evans Collection by 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
- Date
- 1598
- Type
- Flemish nocturnal and sundial
- Maker
- Michiel Coignet
- Diameter
- 108 mm
- Location
- Antwerp
- Signature
- Michael Coignet fe
- Place recorded
- Antwerp
- Maker / attribution
- Michiel Coignet
Design
- Visible features
- • Handle engraved with city names and associated latitudes • Nocturnal index arm engraved with 'Quadrang. vrse minoris' • Volvelle plate marked 'Epacte Anno. 98' • Constructed of brass with a 108 mm diameter
- Provenance and Documentation
- The instrument is signed 'Michael Coignet fe' on the reverse of the index. The handle of the instrument is engraved with various cities and their corresponding latitudes. These additions reflect Coignet's role as a mathematician in Antwerp. The object is part of the Lewis Evans Collection, specifically catalogued as G. 78. It has been documented in scholarly literature, specifically in 'The Measurers: A Flemish Image of Mathematics in the 16th Century' by Jim Bennett.
- Sundial and Celestial Projection
- The reverse side functions as an 'organum Ptolemai' altitude sundial. It incorporates a latitude scale marked 0 to 90 degrees twice. This side utilizes two polar index points, one designated 'Polus arcticus', which are connected by an 'Axis mundi' line. A volvelle plate on this side features a Rojas projection of the celestial sphere. This grid contains parallel lines for solar declination and curved hour lines. A sighting rule and a right-angle index pivot around a central rivet to allow for solar time calculation.
- Construction and Nocturnal Function
- The instrument is a brass disc measuring 108 mm in diameter. One side functions as a nocturnal, used for timekeeping at night. The base-plate includes an outermost scale with divisions for latitude corrections, used when the instrument is held vertically and the index arm is aligned with Ursa Minor. Moving inward from the edge, the base-plate contains a zodiacal calendar with signs and symbols, and a solar declination scale. A series of volvelle plates are mounted above this, featuring an hour scale from 4 pm to 12 to 8 am. The hour plate includes a specific inscription for calculating the date of Easter.
Identification
- Inventory Number
- 44721
- 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: Attribution to the Flemish school of the 16th century is context-based
- Research required: Stylistic relationship to the workshop of Gualterus Arsenius is suggested but not definitively established by the source