Gilbert & Sons Box Sextant

Gilbert & Sons Box Sextant

<< >>
Usage conditions apply
Downloads
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 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.
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
early 19th century
maker
Gilbert and Sons
place made
United Kingdom: England, London
Measurements
overall: 2 3/4 in; 6.985 cm
overall: 1 1/4 in x 2 3/4 in; 3.175 cm x 6.985 cm
ID Number
PH.318442
accession number
234476
catalog number
318442
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Navigation
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.

Comments

Add a comment about this object