Octant

Description:

This octant, which probably dates from the late eighteenth century, has a mahogany frame and index arm. The boxwood scale is graduated every 20 minutes from 0 to 90 degrees and read by transversals to 2 minutes of arc. The top of the scale is numbered counterclockwise for zenith distances. There is also a back sight and a back horizon glass that can be used to measure angles greater than 90°.

Date Made: late 18th century

Location: Currently not on view

See more items in: Medicine and Science: Physical Sciences, Navigation, Measuring & Mapping

Exhibition:

Exhibition Location:

Data Source: National Museum of American History

Id Number: PH.314493Catalog Number: 314493Accession Number: 204107

Object Name: octant

Measurements: overall: 7.6 cm x 37.8 cm x 46 cm; 3 in x 14 7/8 in x 18 1/8 inoverall: 3 in x 14 7/8 in x 18 1/4 in; 7.62 cm x 37.7825 cm x 46.355 cm

Guid: http://n2t.net/ark:/65665/ng49ca746aa-47dc-704b-e053-15f76fa0b4fa

Record Id: nmah_1187745

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