Vertical Disc Dial, Undated
Record status
Individual type · partial
Period
Undated
This vertical disc dial is a German-made instrument constructed from gilt copper, measuring 50 mm in diameter. It comprises three plates, with the central plate featuring a decorated handle for manipulation.
One side of the instrument includes a folding gnomon and hour lines numbered 4 to 12 to 8, divided into quarter-hour increments, accompanied by the initials of the months. The reverse side features a brass arm and a pierced lunar volvelle used to indicate the moon's age against a 29-day lunar scale. Further inscriptions detail solar declination, day length, and night length. One of the plates is crafted from a repurposed engraved printing plate, with remnants of its original text and illustration still visible on the reverse side.
The instrument underwent regilding during the late 19th century. Although parts of the object appear to be missing, the revolving plate mechanism remains functional.
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
- Other sundial
- Diameter
- 50 mm
- Material
- Gilt copper
- Construction
- Repurposed printing plate
- Place recorded
- Germany
- Regilding date
- Late 19th century
- Place of manufacture
- German
Design
- Visible features
- • Decorated handle attached to the central plate • Pierced lunar volvelle showing the age of the moon • Visible markings of 'SONEN LAVF' for sun declination • Gilt copper finish with signs of regilding
- Condition and Attribution
- The dial is currently unsigned, and its precise date of origin remains undetermined. The historical context provided by the Museum of the History of Science attributes the object to a German source. The physical condition reflects some loss of original components, with researchers noting that part of the instrument appears to be missing. Comparisons have been drawn to another instrument in the Epact catalogue, 91925. Unlike that reference, this specific example lacks a latitude scale and notches on the limb, although the plate retains its ability to revolve. The identification of its German manufacture is based on institutional research.
- Construction and Materials
- This vertical disc dial is composed of three plates fashioned from gilt copper, measuring 50 mm in diameter. The central plate is distinguished by an integrated decorated handle, which serves as a grip for the device. A significant feature of the instrument is the material reuse seen on one of the plates, which was salvaged from an earlier engraved printing plate. Traces of the original illustration and text from this printing plate remain visible on the reverse surface. The instrument displays a gilt finish, which the museum notes was applied during a regilding process at the end of the 19th century.
- Dial Functions and Indicators
- The dial serves multiple horological and astronomical functions. On its external face, it features a folding gnomon and a scale of hour lines numbered from 4 to 12 and back to 8, calibrated in quarter-hour divisions. The initials representing the names of the months are positioned opposite the hour scales. The reverse side contains an advanced set of indicators including a brass arm and a pierced lunar volvelle. This volvelle tracks the age of the moon against a circle divided into 29 lunar days. The plate is further inscribed with specific labels for solar declination ('SONEN LAVF') and the duration of day and night ('TAG LENG' and 'NACT LENG'), adjustable via the revolving movement of the plate.
Identification
- Inventory number
- 48208
- 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: Part of the instrument appears to be missing
- Research required: The dating is described as undated
- Research required: The notch on the limb for turning is identified only as probably for that purpose