Astronomical Compendium by Christoph Schissler, 1557

Technical characteristics

Date

1557

Type

Augsburg astronomical compendium

Maker

Christoph Schissler

Signed

CHRISTOPHORVS SCHISSLER ME FECIT AVGVSTE VINDELICORVM ANNO DOMINI 1557

Material

Gilt brass

Dial capacity

42 to 54 degrees

Place recorded

Augsburg

Maker / attribution

Christoph Schissler

Design

Visible features

• Octagonal gilt brass casing with a depth of 15 mm when closed. • Central compass bowl with a diameter of 22 mm displaying cardinal directions. • Integrated horizontal string-gnomon sundial featuring adjustable latitude scales. • Engraved map of central Europe on the interior of the top cover with a radial index.

Construction and Design

The compendium is constructed from gilt brass in an octagonal form, designed with a central box flanked by two hinged covers. The overall diameter reaches 84 mm, with a closed depth of 15 mm. The exterior sides of the central box feature the maker's signature and date in a double-lined border, confirming its creation in 1557 by Christoph Schissler in Augsburg. The internal layout incorporates a complex arrangement of instruments. The dial plate features a horizontal string-gnomon sundial equipped with a catgut string maintained under tension by a barrel-mounted watch spring. A folding arc marked 'SCALA LATITVDINVM POLI' allows for latitude adjustment between 42 and 54 degrees. A compass, 22 mm in diameter, is recessed in the center of this plate, with its base decorated by a profiled warrior head.

Provenance and Observations

The object is held within the Museum of the History of Science, Oxford, identified by inventory number 36175. The instrument is documented as having features consistent with other works by Schissler, though specific modifications and additions are noted. A hole in the center of the map appears designed to house a wind vane, though the source suggests this might be a replacement component borrowed from another source. The lettering 'LINEA FIDUCIAE' on the geographical astrolabe is identified as a potential later addition. Furthermore, an inscription, 'W Burg', is noted as a scratch located on the underside of the compass bowl, though its relationship to the origin or history of the piece remains unconfirmed by the museum documentation.

Astronomical and Cartographic Features

The device functions as a multi-purpose tool, combining timekeeping with cartography. The outer face of the top cover displays a geographical astrolabe, featuring a longitude scale and a polar projection of the earth to the Tropic of Capricorn. The interior of this cover contains an engraved map of central Europe, oriented by a series of wind directions and a radial index for town bearings. The inside back cover houses a lunar volvelle with multiple hour scales and an aspectarium. This component allows for the correlation of moon age, moon phases, and the duration of day and night. Additionally, the exterior back cover is dedicated to a nocturnal and an orthographic projection of the celestial sphere, which serves to determine sunrise and sunset times throughout the year.

Identification

Inventory number

36175

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.