Gurley Surveyor's Vernier Compass

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 signature indicates that it was made after 1876. This compass came to the Smithsonian from the University of Missouri at Columbia.
Ref: W. & L. E. Gurley, A Manual of the Principal Instruments Used in American Engineering and Surveying (Troy, N.Y., 1904), pp. 108-120.
W. Skerritt, "W. & L. E. Gurley's Engraving Machine," Rittenhouse 11 (1997): 97-100.
Currently not on view
W. & L. E. Gurley
place made
United States: New York, Troy
overall length: 15 1/2 in; 39.37 cm
needle: 6 in; 15.24 cm
overall in case: 4 5/8 in x 16 1/2 in x 8 7/16 in; 11.7475 cm x 41.91 cm x 21.43125 cm
ID Number
catalog number
accession number
Credit Line
University of Missouri-Columbia, Department of Civil Engineering
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Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History