Sextant

The sextant has a black-lacquered alloy ladder-pattern frame and a black plastic handle containing a battery for the scale light. The white plastic micrometer drum and clamping screw are positioned on a toothed rim at the bottom of the index arm. The light is incorporated in the index arm. The instrument has four orange shades and three orange horizon shades. Index glass and round horizon-glass, adjustment is made by capped square-headed screws and a separate spanner. A detached prismatic telescope, which is 120 mm in length and has an optical characteristic of 6 x 30mm, with an erect image, is mounted on a non-adjustable bracket.

Accompanying the instrument is a brush and an adjusting spanner.

The instrument has an alloy scale measuring from -5° to 125° by 1°, measuring to 125°. Micrometer to 0.2 arcminutes.

The sextant is contained in a square fitted plywood box with a locking mechanism for securing the instrument when not in use. In the lid there is a certificate of examination from the Deutsches Hydrographisches Institut, Hamburg, dated 23 March 1972, as well as an illustrated instruction leaflet.

Object Details

ID: ZBA0088
Collection: Astronomical and navigational instruments
Type: Sextant
Display location: Not on display
Creator: Plath, C.
Date made: ca. 1970
Credit: National Maritime Museum, Greenwich, London
Measurements: Overall: 180 x 305 x 330mm; Radius: 159 mm
Parts: Sextant