Randolph Surveyor's Vernier Compass

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T. F. Randolph termed this a Patent Vernier Telescope Compass, referring to his 1879 patent (#216,769) for an Improvement in Surveying-Instruments. The raised rim is silvered and graduated to single minutes. The variation arc, located on the compass face, extends ± 20 degrees and reads by double vernier to single minutes. Two level vials are on the face. The signature reads "T. F. RANDOLPH CINCINNATI, O."and "1332" and "PATENTED JUNE 24 ‘79." Theodore F. Randolph (1829-1898) worked in Cincinnati, Ohio, making instruments for surveyors and engineers, and winning awards at local exhibitions.
The telescope assembly is provided with two obviously later additions: a level vial marked "G. F. RICHARDSON, ATHOL, MASS." and a vertical arc marked "G. F. Richardson, Athol, Mass." and "PATENTED Aug. 16, 188x" (the date is illegible).
Ref: T. F. Randolph, Illustrated Catalogue and Price List (Cincinnati, 1892), p. 2.
Currently not on view
Randolph, Theodore F.
needle: 6 in; 15.24 cm
telescope: 7 in; 17.78 cm
overall: 9 1/4 in x 7 1/4 in; 23.495 cm x 18.415 cm
ID Number
patent number
accession number
catalog number
Credit Line
LaVerne Watkins
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History


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