Equinoctial Dial
Record status
Individual type · partial
Period
circa 1570
This universal equinoctial dial, signed by Christoph Schissler, dates to approximately 1570 and originates from Augsburg. The instrument is constructed from gilt brass and measures 44 mm in diameter.
It comprises two detachable sections: a base containing a compass and a circular disc pivoted on a supporting semicircle. The base is engraved with the names and latitudes of 20 towns, cardinal points in German, and winds in Latin. A central eight-leaf flower decorates the brass plate. The disc features an equinoctial pin gnomon dial with hour divisions for summer and winter use, alongside a pierced rotating volvelle indicating the phases and age of the moon, as well as an aspectarium.
The assembly is housed in a round leather case, and the instrument, which lacks a latitude-setting quadrant arm, was bequeathed by Maurice Rosenheim in 1922.
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 1570
- Type
- Augsburg equinoctial dial
- Maker
- Christoph Schissler
- Material
- Gilt brass
- Signature
- CHRISTOPHORVS SCHISSLER FACIEBAT AVGVSTE VINDELICORVM
- Dimensions
- 44 mm in diameter
- Provenance
- Maurice Rosenheim
- Place recorded
- Germany
- Place of origin
- Augsburg
- Maker / attribution
- Christoph Schissler
Design
- Visible features
- • The compass base features engraved town names and latitudes • A rotating volvelle with a moon phase aperture is located at the center of the disc • The dial is mounted on a supporting semicircle • The rim of the compass base displays the maker's signature
- Construction and Design
- The equinoctial dial is composed of two primary sections of gilt brass, measuring 44 mm in diameter. The lower base functions as a compass, featuring an eight-leaf flower at the center and bun feet shaped as flowers on the outer edges. The compass includes a needle with perpendicular brass spikes and is inscribed with the names and latitudes of 20 cities, including Cartagena, Cordova, and Constantinople. The second section consists of a circular disc mounted on a supporting semicircle designed to fit into the base. This disc displays hours on both sides, with the top half designated for summer and the bottom for winter. The instrument includes a rotating volvelle for moon phases and an aspectarium, though the quadrant arm intended for latitude adjustment is currently absent.
- Function and Components
- The dial is designed as a universal tool requiring manual setup. The user must mount the disc on the supports, place it on the compass base, and adjust it for the specific latitude. The compass needle assists in orientation, while the radial engraving of cardinal points and winds supports navigation and usage. The dial uses a pin gnomon system with separate hour scales to account for seasonal sun position changes. A rotating volvelle with a central pin knob allows for the tracking of the moon's age and phase, incorporating an aspectarium for astronomical observation. The complete assembly is preserved with a round leather case featuring impressed circles.
- Signature and Identification
- The instrument bears an engraved signature along the rim of the compass base identifying the maker as Christoph Schissler and the location as Augsburg. The inscription is written in Latin as 'CHRISTOPHORVS SCHISSLER FACIEBAT AVGVSTE VINDELICORVM'. This attribution aligns with the general dating of the instrument to approximately 1570. Additional identifying marks include the museum inventory number MLA 1922, 7-5.3. The object was formally catalogued in F. A. B. Ward's 1981 publication regarding the European scientific instrument collection at the British Museum.
Identification
- Inventory Number
- MLA 1922, 7-5.3
- 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: A quadrant arm for setting the latitude is missing from the instrument
- Research required: The pin for the equinoctial gnomon dial is detached