horizontal dial;
sundial;
compass-dial
- Museum number
- 1854,0103.1
- Description
-
Horizontal compass sun-dial made of gilt brass, in an ivory box.
The ivory lid is fitted with brass discs on both sides, and the lower part of the instrument has a magnetic compass sunk into it; the bottom is plain ivory. Set into the lid is a tide computer, with a 24-hour scale subdivided in half hours, marked in roman numerals twice XII. Inside the hour scale is the sequence of the 32 wind directions, alternately labelled with the initials of the directions. A volvelle has an index to point to the hour, and a lunar age scale, 0-29½. The second volvelle is missing. The disc inside the lid begins at its edge with a calendar scale divided into days and numbered in tens (28 or 31). The months are named in full. Next is a Zodiac scale, divided in degrees, numbered in tens, and named in full. The First Point of Aries is at 10 March. The first (solar) volvelle has its edge divided into the age of the Moon, 0-29½ days, with an index to point to either the date or the position in the Zodiac. The second (lunar) volvelle has an index to point to the Moon's age, and a phase aperture. The centre is occupied with a diagram of the aspects: opposition, trine, quartile, sextile.
The chapter ring is set over the compass in the lower section. It is divided into quarter hours, alternately shaded, with the hours marked in roman numerals from IIII to VIII and with the maker's name inscribed at the bottom. The folding gnomon is held in two sockets, one placed by 12 o'clock, the other within the tracery over the south part of the dial. The gnomon is an open triangle with the short side composed of two S-shaped bars. This dial is designed for a latitude of about 52°. The compass rose is printed from a copperplate and hand coloured (diameter 56). A degree scale (0-90° in quarters) is round the edge. The design is type A-2. The needle is straight, plain one end and with an arrow at the other. The cover is of mica.
- Production date
- 1595-1605
- Dimensions
-
Diameter: 67 millimetres
-
Thickness: 28 millimetres
- $Inscriptions
-
- Location
- Not on display
- Condition
-
Latest: 4 (Oct 2016)
-
Audit 2008: Corrosion around outer lunar volvelle.
- Acquisition date
- 1854
- Department
- Britain, Europe and Prehistory
- Registration number
- 1854,0103.1
