Diptych Dial, circa 1600 (2bee3d)

Technical characteristics

Type

Italian diptych dial

Latitude

Approximately 45 degrees

Material

Ivory and brass

Dimensions

56 x 69 x 12 mm

Place recorded

Italy

Compass Card Decoration

Painted in gold, red and blue

Design

Visible features

• Hinged ivory construction with brass components • Compass needle is missing from the lower leaf • Upper leaf features stars and foliage ornamentation • Pin gnomon dials are present on both interior faces

Attribution and Provenance

The instrument is unsigned and contains no specific date mark, leading to its identification as a product of the circa 1600 period based on technical and stylistic features. The attribution to Italy is derived from the specific calibration of the folding brass gnomon for a latitude of 45 degrees. The piece is currently held within the collection of the Museum of the History of Science, Oxford, identified by inventory number 82248.

Structural Design and Exterior

The diptych dial is fashioned as a two-leaf folding instrument composed primarily of ivory, providing a compact surface for integrated timekeeping components. The overall dimensions are 56 by 69 by 12 mm, facilitating portability. While the outer side of the lower leaf remains entirely blank, the upper leaf exterior provides a horizontal sundial for latitude calibrated to approximately 45 degrees. This exterior dial incorporates a folding brass gnomon to facilitate observation, accompanied by a dedicated viewing hole for the underlying compass. The face is embellished with engraved motifs depicting stars and foliage, contrasted against the plain ivory body. Common hours are marked numerically from IIII to XII to VIII, including half-hour divisions.

Interior Horological Components

The interior faces of the diptych are dedicated to multiple timekeeping systems, primarily utilizing pin gnomons. On the inner side of the upper leaf, a pin gnomon dial is arranged for reading Italian hours, with markings ranging from 14 to 23. This section is decorated with a multiple half-circle motif at the base. The inner side of the lower leaf serves as the central operational area for directional orientation and timekeeping. It houses a recessed compass, though the original magnetic needle is currently missing. The compass card is finished in gold, red, and blue. Below this, a second pin gnomon dial is positioned for Italian hours, marked 10 to 24, and features a circular motif mirroring the upper leaf's design.

Identification

Inventory Number

82248

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.