Surveyor's Vernier Compass

Description:

The rim of this compass is graduated to 30 minutes. The variation arc on the south arm extends 20 degrees either way, and is read by folded vernier to 2 minutes. Two level vials are on the north arm, and an outkeeper is on the south arm. The side of one vertical sight is graduated to half degrees, for determining angles of elevation or depression. The machine-engraved "W. & L. E. Gurley Troy, N.Y." signature indicates a date of manufacture after 1876. The lack of serial number indicates a date before 1908.

Ref: W. & L. E. Gurley, A Manual of the Principal Instruments Used in American Engineering and Surveying (Troy, N.Y., 1904), pp. 108-120.

Maker: W. & L. E. Gurley

Location: Currently not on view

Place Made: United States: New York, Troy

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

Exhibition:

Exhibition Location:

Related Publication: W. & L. E. Gurley. Manual of the Prinicipal Instruments Used in American Engineering and Surveying; 37th Edition

Credit Line: Columbia University

Data Source: National Museum of American History

Id Number: PH.335209Catalog Number: 335209Accession Number: 317998

Object Name: Surveyor's Vernier Compass

Measurements: overall length: 15 1/2 in; 39.37 cmneedle: 6 in; 15.24 cmoverall in case: 4 13/16 in x 16 1/2 in x 8 1/2 in; 12.22375 cm x 41.91 cm x 21.59 cm

Guid: http://n2t.net/ark:/65665/ng49ca746a8-88c1-704b-e053-15f76fa0b4fa

Record Id: nmah_997210

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