Spencer Browning & Co. Sextant

This sextant is somewhat unusual in that it has a brass frame, reinforced brass index arm, and ivory (rather than metal) scale. This scale is graduated every 10 minutes from -5° to +125° and read by vernier with tangent screw and swinging magnifier to 20 minutes of arc. The "Spencer Browning & Co., London" inscription on the arc refers to a firm that was in business from 1840 to 1870.
Currently not on view
Object Name
date made
Spencer, Browning & Co.
Physical Description
ivory (overall material)
brass (overall material)
mahogany (overall material)
glass (overall material)
radius: 7 1/2 in; 19.05 cm
place made
United Kingdom: England, London
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
George T. Blair
Additional Media

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