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
Object Name
compass (surveyor's vernier)
date made
Mahn, Herman
overall length: 15 1/2 in; 39.37 cm
needle: 5 1/8 in; 13.0175 cm
place made
United States: Missouri, St. Louis
ID Number
catalog number
accession number
Measuring & Mapping
Surveying and Geodesy
See more items in
Medicine and Science: Physical Sciences
Surveying and Geodesy
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
University of Missouri at Columbia.
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