Surveying Quadrant by Christoph Schissler

Technical characteristics

Date

1579

Type

Augsburg surveying quadrant

Maker

Christoph Schissler

Materials

Gilt copper

Dimensions

345 mm square

Provenance

Presented to the Bodleian Library in 1601 by Sir Josias Bodley

Place recorded

Augsburg

Maker / attribution

Christoph Schissler

Place of manufacture

Augsburg

Design

Visible features

• Decorative border featuring European and Ottoman geometers • Gilt surfaces with visible copper wear • Rotating index rule with engraved scale • Attached cartouche signed by Christoph Schissler

History and Provenance

The instrument’s history is well-documented from the early 17th century, when it was presented to the Bodleian Library in Oxford in 1601 by Sir Josias Bodley. It remained in the Library's collection for centuries before being placed on loan to the Museum of the History of Science in 1952. While the instrument was originally intended to be part of a high-status collection, its primary patron remains unknown. At the time of its donation, the quadrant was accompanied by a matching level, which has been preserved alongside the main object. The instrument is designed to stand on its own base, which incorporates two decorated circular sights featuring pinholes for sighting operations, and it includes a suspension point for a plumb bob, facilitating its use as a survey tool.

Construction and Decoration

The surveying quadrant is a substantial instrument measuring 345 mm square, crafted from multiple layers of gilt copper that are secured with screws and rivets. The instrument is marked by extensive decorative relief work covering its outer surfaces and border. These reliefs feature a variety of figures, specifically European and Ottoman geometers, engaged in surveying tasks with instruments including quadrants, dividers, and cross staffs. The wear on the gilding reveals the underlying copper substrate across the instrument's surface. On the lower frame, a cartouche contains the formal signature of the maker alongside vignettes depicting an instrument workshop environment with various tools. Originally, the lower frame featured two hinged pieces, though only one currently survives, exhibiting a form comparable to a belt buckle.

Geometric Scales and Functionality

The obverse of the instrument features a quadrant scale accompanied by a rotating index rule marked 'SCALA GEOMETRICI CVRSORIS'. This rule pivots from the top left and bears double scales of equal parts. The quadrant itself includes vertical lines and a transversal scale, with the arc inscribed 'PVNCTA ALTITVDINIS STATIONIS', indicating its role in measuring heights and distances. The reverse side serves as a repository for complex calculations, dominated by a large table titled 'TABVLA SCALAE GEOMETRICAE MILLE PVNCTORVM VMBRAE VERSAE ET RECTAE'. This table, along with a secondary table for 200 points, allowed the user to calculate dimensions without manual arithmetic. Additional features include a slot with a sliding mechanism on the reverse, potentially used for clamping the rule, and an inscription reading 'SCALA DEFERENTIS QVI REGVLAM HYPOTHENVSA ADDVCIT ATQ<VE> ABDVCIT'.

Identification

Accession Number

48659

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.