Italian Scallop-Shaped Diptych Dial
Record status
Individual type · partial
Period
circa 1600
This unsigned diptych sundial, attributed to Italian origin circa 1600, is held in the Museum of the History of Science, Oxford. Measuring 64 x 71 x 10 mm, the instrument is constructed from ivory and brass.
Its form is essentially circular but modified by a straight hinge, resulting in a scallop-like appearance. The upper leaf contains a pin gnomon dial for Italian hours and a string gnomon dial for common hours. The lower leaf houses a compass, a string gnomon dial marked with common hours, and a pin gnomon dial for Italian hours. The dial displays painted decorative motifs of stars and leaves, alongside a compass card finished in green, red, and gold.
The object shows structural damage, including a cracked upper leaf held by two brass plates and a cracked compass glass, with the string gnomon currently absent.
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
- circa 1600
- Type
- Italian diptych dial
- Maker
- Unsigned
- Material
- Ivory and brass
- Dimensions
- 64 x 71 x 10 mm
- Place recorded
- Italy
- Country of origin
- Italian
Design
- Visible features
- • Scallop-shaped ivory leaf structure • Compass with cracked glass and polychrome card • Pin and string gnomon dials for common and Italian hours • Brass plate repairs on the upper leaf
- Timekeeping Functions
- The device is equipped with multiple sundial configurations to track time. The upper leaf includes a pin gnomon dial calibrated for Italian hours, marked with red numerals ranging from 14 to 24. It also features a string gnomon dial marked for common hours using Roman numerals from VI through XII to VI. The lower leaf contains a compass, which is central to the orientation of the instrument, although the protective glass is cracked. Below the compass, another string gnomon dial provides common hours marked from IIII to XII to VIII. Adjacent to this is a second pin gnomon dial for Italian hours, marked with numerals from 9 to 23. This complex arrangement allows for the reading of multiple systems of time, although the missing string gnomon prevents full use of the common hour dial.
- Construction and Design
- The dial is constructed from ivory and brass with an unusual scallop-like silhouette derived from a circular base. The hinge mechanism dictates the overall form, allowing the two leaves to fold. The exterior surfaces of both leaves are blank. The current physical state of the ivory reflects significant stress, as the upper leaf has sustained cracks requiring reinforcement with two brass plates to maintain integrity. Decoration is focused on the interior surfaces. The compass card located in the lower leaf features a color palette of red, green, and gold. The inner faces also feature engraved and painted ornamentation, specifically stars and leaves, which decorate the spandrel spaces surrounding the common hour dial on the lower leaf. The instrument retains its brass hardware, although the string component of the gnomon is currently missing.
- Provenance and Documentation
- The object is preserved by the Museum of the History of Science in Oxford, recorded under the inventory number 54660. Research into this class of object has been associated with the study of Nuremberg ivory dials, as referenced in P. Gouk's 1988 publication on the subject. As an unsigned instrument, the exact origin relies on stylistic attribution. The documentation provided confirms the materials and physical dimensions, as well as the present condition of the dial. The museum maintains rights to the information and images regarding the item, which is formally identified in their collection as an Italian diptych dial dated to approximately 1600.
Identification
- Reference
- 54660
- 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 exact provenance of the unsigned object remains unverified beyond the historical attribution.
- Research required: The functional status of the dial is compromised due to the missing string gnomon and structural cracking.