Box Sextant
date: label: date made
content: early 19th century
name: label: maker
content: Gilbert and Sons
notes: label: Description
content: 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.
label: Description
content: This example has a silvered scale that is graduated every 30 minutes from -3° to +148° and read by vernier with swinging magnifier to single minutes of arc. The "Gilbert & Sons, London" inscription above the magnifier refers to a Navigation Warehouse in London that flourished from 1806 to 1819.
label: Description
content: 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.
label: Location
content: Currently not on view
place: label: place made
content: United Kingdom: England, London
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Navigation
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content: Measuring & Mapping
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.318442
label: accession number
content: 234476
label: catalog number
content: 318442
objectType: label: Object Name
content: box sextant
physicalDescription: label: Measurements
content: overall: 2 3/4 in; 6.985 cm
label: Measurements
content: overall: 1 1/4 in x 2 3/4 in; 3.175 cm x 6.985 cm