Surveyor's Vernier Compass


Theodore F. Randolph (1829-1898) worked in Cincinnati, Ohio, making instruments for surveyors and engineers, and winning awards at local exhibitions.

He termed this instrument 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 on the compass face extends ± 20 degrees and reads by double vernier to single minutes. Two level vials are on the face. The inscriptions read "T. F. RANDOLPH CINCINNATI, O."and "1332" and "PATENTED JUNE 24 ‘79."

The telescope assembly is provided with two later additions: a level vial marked "C. F. RICHARDSON, ATHOL, MASS." and a vertical arc marked "C. F. Richardson, Athol, Mass." and "PATENTED Aug. 16, 1887."

Ref: T. F. Randolph, Illustrated Catalogue and Price List (Cincinnati, 1892), p. 2.

Charles F. Richardson, “Surveyor’s Transit,” U.S. Patent 368,308 (August 16, 1887).

Maker: Randolph, Theodore F.

Location: Currently not on view

See more items in: Medicine and Science: Physical Sciences, Surveying and Geodesy, Measuring & Mapping


Exhibition Location:

Related Publication: Randolph, T. F.. Illustrated Catalogue and Price List

Credit Line: LaVerne Watkins

Data Source: National Museum of American History

Id Number: 1989.0403.10Patent Number: 216769Accession Number: 1989.0403Catalog Number: 1989.0403.10

Object Name: surveyor's compass

Measurements: needle: 6 in; 15.24 cmtelescope: 7 in; 17.78 cmoverall: 9 1/4 in x 7 1/4 in; 23.495 cm x 18.415 cm


Record Id: nmah_997293

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.