Diptych Dial by Georg Karl
Record status
Individual type · partial
Period
1598
This diptych dial, created in 1598 by Georg Karl, is a gilt brass scientific instrument measuring 104 x 88 x 12 mm. It comprises a rectangular box featuring a cover secured by a spring catch, with sides decorated with engraved foliage.
The instrument serves as a complex multifunctional device, housing two horizontal pin gnomon sundials, a vertical string gnomon sundial, a horizontal string gnomon sundial, a lunar volvelle, a horary volvelle, an integrated compass, a plumb level, and an astronomical table. The dial face incorporates diverse time-keeping scales, including common, Italian, and Babylonian hours, along with declination lines corresponding to zodiacal signs.
This object is documented as the sole surviving instrument attributed to Georg Karl.
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
- German diptych dial
- Maker
- Georg Karl
- Material
- Gilt brass
- Dimensions
- 104 x 88 x 12 mm
- Inscriptions
- Latitude references and astronomical terminology
- Place recorded
- Germany
- Compass diameter
- 23 mm
- Maker / attribution
- Georg Karl
Design
- Visible features
- • The instrument features a centrally located 23 mm diameter compass with a silvered base plate. • The interior cover features a vertical string gnomon sundial alongside a horary conversion volvelle. • The base plate contains a plumb bob assembly with a sprung silvered support. • The engraving includes a table listing eight German towns, all assigned a latitude of 48 degrees.
- Signatures and Provenance
- The instrument bears a clear signature from Georg Karl, dated to 1598. This dial is noted in the provided documentation as the only known surviving instrument produced by this maker. The signature is prominently displayed on the reverse of the cover. The item is currently held by the Museum of the History of Science, Oxford. The inscriptions on the piece indicate it was specifically calibrated for a latitude of 48 degrees, referencing several German towns such as Munich and Strasbourg.
- Condition and Specific Details
- The object shows evidence of historical use and modification. The horizontal pin gnomon sundial on the cover is missing its gnomon. Additionally, a crude arrow has been added to the base plate to record magnetic variation, and a manufacturing error exists where the zodiacal symbol for Taurus was erroneously stamped in place of Aries. The compass bowl is retained by a clasp mechanism, and the instrument's base features a comprehensive table detailing day and night lengths for sixteen specific days of the year.
- Construction and Functionality
- The instrument is constructed from gilt brass and is configured as a rectangular box with a single hinged cover. The exterior and interior surfaces are heavily engraved with decorative leaf patterns, scrollwork, and various astronomical scales. The internal layout includes a compass, four distinct sundial configurations, a plumb level, and multiple volvelles. It incorporates common, Italian, and Babylonian hour scales alongside a lunar volvelle and an aspectarium.
Identification
- Reference
- 47563
- Inventory number
- 47563
- 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 gnomon on the horizontal pin gnomon sundial located on the cover is missing.
- Research required: A Taurus symbol was reportedly stamped in the place of Aries during production.
- Research required: The exact latitude settings and historical usage patterns remain specific to the design's 48-degree calibration.