Frodsham Sextant

This sextant has a brass frame. The silvered scale is graduated every 10 minutes from -5° to +145° and read by vernier with tangent screw and swinging magnifier to single minutes of arc. The inscriptions read "Frodsham, Liverpool" and "2602." It came from Vassar College, and may have been used by the professor of astronomy, Maria Mitchell.
Ref: Gloria Clifton, Directory of British Scientific Instrument Makers 1550-1851 (London, 1995), p. 106.
Currently not on view
Object Name
date made
ca 1865
Charles Frodsham
Physical Description
mahogany (overall material)
brass (overall material)
silver (overall material)
glass (overall material)
radius: 8 in; 20.32 cm
place made
United Kingdom: England, Liverpool
ID Number
catalog number
accession number
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Vassar College
Additional Media

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