Nocturnal

Nocturnal and horizontal dial for latitude 43° 45'. Set into the handle is a compass with a cover. On the obverse side is a lunar volvelle, on the reverse side is a nocturnal. The initials 'JF' are engraved on the dial-plate.
For use with Little Bear only.
Compass set into handle. Cardinal points marked, Glass cover held by brass ring.
Date scale with months by initials and zodiac signs, subdivided to 2 days.
Main disc: Hour circle divided clockwise to 30 min. Gnomon folds flat when not in use.
Lunar volvelle: Fixed circle has lunar age scale anticlockwise to 1 day. Rotatable disc has hour scale clockwise. Circular aperture displays moon phases pictorially

Object Details

ID: AST0134
Collection: Astronomical and navigational instruments
Type: Nocturnal
Display location: Not on display
Creator: F., J.
Date made: circa 1700; 17th Century
Credit: National Maritime Museum, Greenwich, London, Caird Collection
Measurements: Diameter: 19 x 115 x 70 mm
Parts: Nocturnal