Warren-Knight Co. Box Sextant

Warren-Knight Co. Box Sextant

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Description
A box (or pocket) sextant works like a traditional sextant, but here the mechanism is enclosed in a brass box of about 3 inches diameter. William Jones, a leading instrument maker in London, introduced the form in 1797.
This example probably belonged to Llewellyn N. Edwards (1874-1952), a structural engineer. It has a silvered scale graduated every 30 minutes from -5° to +150° and read by vernier with swinging magnifier to single minutes of arc. The inscription reads "WARREN-KNIGHT CO. PHILADELPHIA. MADE IN ENGLAND." Warren-Knight began in business in 1912.
Ref: William Jones, "Description of a New Pocket Box Sextant," in George Adams, Geometrical and Graphical Essays, 2nd ed. by William Jones, (London, 1797), pp. 283-285.
Location
Currently not on view
Object Name
box sextant
date made
after 1912
dealer
Warren-Knight Co.
place made
United Kingdom: England
Measurements
overall: 3 1/4 in; 8.255 cm
overall: 4 3/8 in x 4 in x 2 in; 11.1125 cm x 10.16 cm x 5.08 cm
ID Number
PH.333796
catalog number
333796
accession number
296611
Credit Line
Bequest of Carolyn H. Edwards
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Data Source
National Museum of American History
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