Surveyor's Vernier Compass


This "Bate London" inscription on this unusual surveyors compass refers to the London instrument maker, Robert Brettell Bate (1782-1847). The outer edge of the face is graduated to 10 degrees, and numbered from north and south. The rim is graduated to single degrees, numbered counterclockwise from north, and read by vernier to 6 minutes.

Unlike most vernier compasses, this one has no variation arc. And unlike most surveyor's compasses, here the sight vanes are attached to the arms, and the arms screw onto the compass box. A level vial is also mounted below the compass box, and a socket, so that the compass can be used with a jacob staff.

Maker: Bate, Robert Brettell

Location: Currently not on view

Place Made: United Kingdom: England, London

See more items in: Medicine and Science: Physical Sciences, Surveying and Geodesy, Measuring & Mapping


Exhibition Location:

Data Source: National Museum of American History

Id Number: PH.319793.1Accession Number: 239772Catalog Number: 319793.1

Object Name: Surveyor's Compasssurveyor's compass

Measurements: overall: 15 in x 5 1/2 in; 38.1 cm x 13.97 cmoverall: 8.8 cm x 17 cm x 17 cm; 3 7/16 in x 6 11/16 in x 6 11/16 inoverall in case: 3 3/8 in x 6 7/8 in x 6 3/4 in; 8.5725 cm x 17.4625 cm x 17.145 cm


Record Id: nmah_688758

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