Vertical Disc Dial, 1564
Record status
Individual type · partial
Period
1564
This 50 mm vertical disc dial, held by the Museum of the History of Science, Oxford (inventory 41123), is an unsigned German instrument dating to 1564. The construction consists of five superimposed gilt copper discs, featuring a suspension handle cast and engraved in the form of a double dragon's head.
One side contains a brass arm with a pierced, engraved lunar volvelle for tracking moon phases, alongside a perpetual calendar showing days of the month, daylight and night lengths, and ruling planets. The opposing side features a folding gnomon used to indicate hours numbered from 4 to 12 to 8. Various plates include internal notches and hidden inscriptions, such as the signature-like 'Jah. 1564 Lub Soll' engraved on an inner face, which are only accessible when the instrument is disassembled.
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
- 1564
- Type
- Other sundial
- Origin
- Germany
- Material
- Gilt copper
- Gnomon type
- Folding
- Place recorded
- Germany
- Internal inscription
- Jah. 1564 Lub Soll
Design
- Visible features
- • Handle shaped as a double dragon head • Folding gnomon arm at the centre • Engraved circular hour scales numbered 4 to 12 to 8 • Multi-plate construction with visible edge notches
- Functions and Markings
- The dial functions as both a solar and calendrical tool. One side features a brass arm equipped with a pierced and decorated lunar volvelle for tracking the phases of the moon. This face also supports a perpetual calendar, indicating the total days of the month, the length of the day and night, and the daily ruling planet through specific engraved references. The opposite face includes a folding gnomon intended to indicate common hours, which are engraved on the limb and numbered from 4 to 12 to 8. This face also includes the initials of the months and a central inscription referring to the seven planets. Additional planet symbols are revealable via the internal plates to assist with the governing planet indications.
- Signature and Identity
- The instrument is documented as unsigned on its external surfaces, though an internal marking reads 'Jah. 1564 Lub Soll'. This engraving is found on the inner face of one of the plates, reinforcing the date of 1564 established for the object. Despite these markings, the specific workshop or maker remains unrecorded. The instrument displays structural similarities to other recorded devices, specifically those catalogued as Epact 86254.
- Construction and Design
- The instrument is composed of five superimposed gilt copper discs, measuring 50 mm in diameter. The assembly is held by a handle cast and engraved in the form of a double dragon's head. The design incorporates mechanical complexity beyond the primary dial face, with several plates featuring notches along the limb to facilitate turning. The dial contains numerous engravings, some of which are located on the internal faces of the plates and are not visible when the instrument is fully assembled. These include alphabetic inscriptions and technical annotations, such as 'I K' and 'leibi gasteig', which reveal additional details regarding the construction and potential internal adjustments of the dial.
Identification
- Inventory number
- 41123
- 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: Exact maker not confirmed as unsigned
- Research required: Meaning of the internal 'I K' and 'leibi gasteig' inscriptions
- Research required: Specific function of the internal discs relative to their hidden engravings