Surveyor's Vernier Compass
name: label: maker
content: W. & L. E. Gurley
notes: label: Description
content: 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 seconds. There is an outkeeper on the south arm, and two level vials on the north. The hand-engraved inscription indicates a date of manufacture between 1852 and 1876. New, it cost $50.
label: Description
content: The compass is equipped with a telescope that attaches to one of the sight vanes, and that is marked "W. & L. E. GURLEY, TROY, N.Y. PATENTED JULY 9, 1878." The reference is to patent #205,712 describing an Improvement in Telescope Attachments for Surveyors’ Compasses, and granted to William Gurley and Lewis E. Gurley.
label: Description
content: Ref: W. & L. E. Gurley, <i>A Manual of the Principal Instruments Used in American Engineering and Surveying</i> (Troy, N.Y., 1871), pp. 23-27.
label: Description
content: W. Skerritt, "W. & L. E. Gurley's Engraving Machine," <i>Rittenhouse</i> 11 (1997): 97-100.
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, Troy
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Surveying and Geodesy
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content: Measuring & Mapping
publisher: label: Related Publication
content: W. & L. E. Gurley. Manual of the Prinicipal Instruments Used in American Engineering and Surveying; 17th Edition
creditLine: label: Credit Line
content: Columbia University
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.335210
label: catalog number
content: 335210
label: accession number
content: 317998
objectType: label: Object Name
content: Surveyor's Vernier Compass
physicalDescription: label: Measurements
content: overall length: 15 1/2 in; 39.37 cm
label: Measurements
content: needle: 6 in; 15.24 cm
label: Measurements
content: overall in case: 4 5/8 in x 16 1/2 in x 8 3/8 in; 11.7475 cm x 41.91 cm x 21.2725 cm