Mahn Surveyor's Vernier Compass

This compass marked "Mahn & Co. St. Louis, Mo." dates from the period 1891-1906, when Herman Mahn was trading as such. It has a variation arc on the south arm that extends 24 degrees either way. The vernier is moved by a tangent screw on the south arm, and reads to 2 minutes. An outkeeper is on the south arm, and two level vials are on the north arm.
Currently not on view
date made
Mahn, Herman
place made
United States: Missouri, St. Louis
overall length: 15 1/2 in; 39.37 cm
needle: 5 1/8 in; 13.0175 cm
overall in case: 4 7/8 in x 16 1/2 in x 7 5/8 in; 12.3825 cm x 41.91 cm x 19.3675 cm
ID Number
catalog number
accession number
Credit Line
University of Missouri at Columbia.
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Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History