Wall Surveyors' Vernier Compass

Description
This is an usually large compass, with an unusual skeletal design. The rim is graduated to 30 minutes. The variation arc on the north arm extends 20 degrees either way, and is read by folded vernier to single minutes. Two level vials are on the south arm. The "Thos Wall Cleveland O." signature refers to Thomas Wall (1797-1854), an instrument maker who worked in Cleveland, Ohio, in the years 1845-1854.
Location
Currently not on view
date made
1845-1854
maker
Wall, Thomas
place made
United States: Ohio, Cleveland
Measurements
overall length: 17 5/8 in; 44.7675 cm
needle: 6 7/8 in; 17.4625 cm
overall in case: 4 1/4 in x 18 9/16 in x 8 3/4 in; 10.795 cm x 47.14875 cm x 22.225 cm
ID Number
PH.335532
accession number
321714
catalog number
335532
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History, Kenneth E. Behring Center

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