Quadrans Vetus (Old Quadrant)
Record status
Individual type · partial
Period
circa 1300
This brass instrument is an example of a rare quadrans vetus, or old quadrant, originating from France and dating to circa 1300. It measures 158 mm in radius and features a design that allows for adjustment to any latitude through a sliding, curved plate that moves within a slot above the degree arc.
The instrument displays complex astronomical scales, including unequal hour lines, a shadow square, a calendar scale, and a zodiac scale. The reverse side accommodates a lunar volvelle, which was recently reunited with the quadrant after previously being separated. All inscriptions are executed in Gothic lettering. The device includes a plumb bob with a pearl bead and a ring for suspension. This quadrant, which was once part of the Lewis Evans collection, is currently held by the Museum of the History of Science in Oxford, inventory number 52020.
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
- Quadrans vetus
- Origin
- French
- Radius
- 158 mm
- Script
- Gothic
- Material
- Brass
- Place recorded
- France
Design
- Visible features
- • Plumb bob suspended from the upper corner with a bead • Gothic lettering engraved throughout the scales • Shadow square marked 0 to 12 visible on the primary face • Sliding plate mechanism visible in the arched slot
- History and Provenance
- The quadrant was formerly part of the Lewis Evans collection, now housed within the Museum of the History of Science in Oxford. The instrument had historically been separated from its lunar volvelle, but the two components have been recently reunited. The instrument remains unsigned. Its construction and the style of its inscriptions are attributed to France, with a date of origin around 1300.
- Physical Configuration
- The instrument is a brass quadrant with a radius of 158 mm. It includes a ring for suspension at the apex. On the primary side, a shadow square is present, marked from 0 to 12. Superimposed over this are unequal hour lines numbered 1 to 6 and 7 to 12, the latter engraved in mirror script. A sliding, curved plate is positioned within a slot above the degree arc, which is calibrated from 0 to 90 degrees. A plumb bob is attached to the instrument, featuring a small pearl bead. The reverse side of the object is designed to hold a lunar volvelle. Centrally, the volvelle is decorated with an eight-leaf floral motif. This side also contains circular engravings representing a calendar scale and a zodiac scale, both of which are divided to correspond to the days of the year.
- Function and Adjustment
- The instrument is categorized as a quadrans vetus. The sliding plate is engineered to move within a slot, allowing the user to adjust the instrument for different latitudes. The sliding plate is engraved with various temporal and astrological data, including the names and days of the months and the names of the zodiacal signs. The lunar volvelle provides tracking for the lunar month, with days numbered 1 to 29.5. The calendar scale is divided into months of 30 or 31 days, and the zodiac scale is divided accordingly, with markings every 10 units.
Identification
- Inventory Number
- 52020
- 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 sliding curved plate is only half-preserved
- Research required: The lunar volvelle on the reverse side is partially missing