Azimuth compass

Azimuth compasses are used for taking accurate bearings from a ship. They therefore have vertical sights on top and the compass card is divided into degrees as well as the points of the compass.

This example is a dry card compass. Each quarter of the card is divided from 0 to 90 degrees, with 0 at the north and south points. The numbers are printed in reverse, so that they can be read when viewed through the mirror sight. The back sight has two coloured filters (one red, one green) for use in bright conditions or when looking towards the sun, and there is an additional filter for the fore sight. The compass is held on gimbals, which allow it to remain level, and has a locking screw on the side to hold the compass card in place when not in use.

The maker’s name is inscribed on top of the compass, and ‘2283’ is stamped onto it in a number of places.

Object Details

ID: ACO0034
Collection: Astronomical and navigational instruments
Type: Dry card compass
Display location: Not on display
Creator: Edward John Dent & Co.
Date made: circa 1899
Credit: National Maritime Museum, Greenwich, London, Admiralty Compass Observatory
Measurements: Overall: 300 mm x 265 mm x 225 mm