Surveyor's Vernier Compass

W. & L. E. Gurley

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.