Gurley Surveyor's Vernier Compass

Description
Gurley described this as "a most excellent and portable little instrument," noting that it "is especially useful for the surveyor of government lands." New, it cost $21. The rim is graduated to 30 minutes. The right side of the face is graduated to degrees, and numbered every 10 degrees from west to north, and from west to south. The outside of the box has a variation arc that extends ± 20 degrees, and that reads by folded vernier to 5 minutes. The U.S. Geological Survey, was established in 1879, and transferred this example it to the Smithsonian in 1907.
Ref: W. & L. E. Gurley, A Manual of the Principal Instruments Used in American Engineering and Surveying (Troy, N.Y., 1878), p. 138.
Location
Currently not on view
Object Name
compass (pocket with folding sights)
maker
W. & L. E. Gurley
Measurements
overall: 4 3/8 in; 11.1125 cm
needle: 3 1/2 in; 8.89 cm
place made
United States: New York, Troy
ID Number
PH*247917
catalog number
247917
accession number
47736
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History, Kenneth E. Behring Center

Comments

Add a comment about this object