Horizontal dial

Portable horizontal dial for latitudes 54°-57° North. The dial is slightly elevated by a brass leg set underneath the gnomon point. On the dial-plate, three concentric hour scales are marked for 57°, 56° and 55°, and a circular hole at the lower end suggests that something is missing. Towns are marked at each end of each hour scale, the implication being that the scale in which a town is marked is the scale that should be used in that particular place. The gnomon is hinged, folding flat when not in use. The compass is surrounded by a wheatsheaf motif and has a crude line indicating the magnetic variation at 3° West of North.

This instrument was probably produced during the time when Schleswig-Holstein was part of Denmark, since the towns listed are almost all Danish or in this northern region of Germany. The province was eventually ceded to Prussia in 1866. The scales for 56 and 57 degrees are extremely inaccurate and appear to have had the hours marked on the half-hour lines inadvertently. The latitudes on the scale include some inaccuracies: for example, 57° for Copenhagen (actually 55° 40'). The dial is set into a rectangular book-shaped case which is curved at one end.

For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.

Object Details

ID: AST0396
Collection: Astronomical and navigational instruments
Type: Horizontal dial
Display location: Not on display
Creator: Unknown
Date made: early 17th century
Credit: National Maritime Museum, Greenwich, London, Caird Collection
Measurements: Overall: 10 x 70 x 94 mm
Parts: Horizontal dial