Nocturnal by Hans Dorn
Record status
Individual type · partial
Period
1491
This 1491 nocturnal, crafted from silvered brass by the Dominican monk Hans Dorn in Vienna, is an early multi-functional scientific instrument. Measuring 121 mm in diameter, the object integrates a circular disc with an extension tapering into a V-shaped handle, which supports an attached box.
The front of the primary disc is engraved for latitude 47°, featuring a celestial equator, unequal hour lines, and astrological houses. A rotating ecliptic circle and ruler facilitate astrological calculations and hour conversions. The reverse side serves as a nocturnal with various circular scales, including calendrical and lunar mansion indices, alongside a lunar phase aperture containing crushed azurite. Housed within the box is an equatorial dial and a compass, the latter noted for an 8°E magnetic deviation.
The instrument's surface is extensively engraved with a list of European cities and their respective latitudes, concluding with a signature identifying the maker and the year of production.
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
- 1491
- Type
- Central European nocturnal
- Maker
- Hans Dorn
- Material
- Silvered brass
- Signature
- Prvder Hanns Dorn Prediger Orden von Wien
- Dimensions
- 121 mm diameter
- Place recorded
- Austria
- Compass deviation
- 8 degrees east
- Maker / attribution
- Hans Dorn
Design
- Visible features
- • Engraved list of cities and latitudes on box exterior • Rotating ecliptic circle with Latin zodiac names • Lunar phase aperture with crushed azurite inlay • Missing pin gnomon and compass needle
- Construction and Design
- The nocturnal is constructed from silvered brass and maintains a circular format with a tapering handle. The front face is calibrated for latitude 47° and includes detailed engravings for unequal hours and astrological houses. An ecliptic circle rotates over the main plate, which is further operated by a rotating ruler. The instrument allows for complex astronomical calculations, including the conversion between equal and unequal hours, and is specifically designed for use as a nocturnal. The reverse side of the primary disc contains a sequence of circular scales that integrate calendrical and astronomical data. These include zodiac markers, lunar mansion indicators, and shadow scales. A secondary rotating disc features two arms resembling an alidade, designed with sighting vanes. A circular aperture on this disc allows for the visual representation of lunar phases, achieved using crushed azurite. The central hole of the instrument acts as a sighting aperture for nocturnal observations.
- Box and Integrated Components
- Attached to the handle is a box containing supplementary timekeeping components. An equatorial dial, formed as a foliate scroll, is housed inside and can be adjusted for latitude using a foldable arm. A latitude scale is engraved into the interior of the box floor to facilitate this setting. The box also contains an inset compass. Although the glass is a replacement and the needle is missing, the instrument is associated with a magnetic deviation of approximately 8°E. The outer lid features a hole, enabling visibility of the compass dial while the box is closed.
- Signatures and Geographical Markings
- The instrument is marked with a comprehensive list of cities across its exterior and interior surfaces, each accompanied by its latitude. This list serves as a reference for the user across various locations in Europe, including cities such as Vienna, Nuremberg, and Prague. The maker's signature is engraved on the outside of the box bottom. It explicitly attributes the construction to Brother Hans Dorn of the Dominican order in Vienna, dated to 1491. This text also comments on the utility of the compass integration.
Identification
- Reference
- MLA 1894,6-15.1
- Inventory Number
- MLA 1894,6-15.1
- 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 compass needle is missing and the glass is a replacement
- Research required: Pin gnomon for the equatorial dial is missing