Davis Sextant

William A. Davis was an Englishman who settled in San Leandro, California, and offered a range of inexpensive plastic nautical instruments for boating enthusiasts. He introduced the Mark III sextant in 1963, and the instrument is still in production. Like the sextant that Cruver made for the U.S. Maritime Commission during the war, the Mark III is made of polystyrene. It has a simple eye tube, and a scale that is graduated every degree from -35° to +100° and read by vernier to 2 minutes of arc. The original Mark III cost $9.95. This example was probably made in the late 1960s. The sextant's arm is inscribed "DAVIS INSTRUMENTS CORP. / 857 THORNTON STREET / SAN LEANDRO / CALIF. 94577 / U.S.A."
Ref: William A. Davis, How to Find Your Position with a Sextant (San Leandro, 1966 and 1968).
Currently not on view
Object Name
Davis Instruments Corporation
Physical Description
plastic (overall material)
radius: 7 in; 17.78 cm
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
Roger Sherman

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