Accession No
0013
Brief Description
ivory diptych dial, by Jacob Karner, German, 1627 (c)
Origin
Germany; Nuremberg (Nürnberg)
Maker
Karner, Jacob
Class
dials
Earliest Date
1627
Latest Date
1627
Inscription Date
Material
ivory; metal (brass)
Dimensions
length 102mm; breadth 67mm; thickness 22mm
Special Collection
Hutchinson Collection
Provenance
Inscription
‘I3K’ (leaf IIb)
‘3’ (compass)
Description Notes
Ivory diptych dial with brass fittings. Decorated on outer faces of leaves.
Leaf Ia: 16-point wind rose with points named; 32 numbered points from 1 at East. Brass index (wind vane missing). Pierced to show N-point of compass and house plumb-bob. 4 small brass feet.
Leaf Ib: dial for unequal hours and hours of daylight divided 1 - 12 and 8 - 16 and 16 - 8, all numbered by 1. Zodiacal signs as calendar scale. Table of towns and latitudes. Four attachment points for string gnomon, marked 51, 48, 45 and 42.
Leaf IIa: horizontal dial for 42, 45, 48 and 51. Hour scales divided 4 - 12, 1 - 8, numbered by 1, subdivided to 30 minutes (to 15 minutes on outermost scale; 1-2-2000). Inset compass with cardinal points marked in Latin; meridian line offset c.5˚E for magnetic variation; needle and glass missing. Replacement string gnomon (missing; 1-2-2000). Two subsidiary dials, each with pin gnomon for Italian hours (divided 10 - 22, numbered by 1) and Babylonian hours (divided 2 - 14, numbered by 1; gnomon loose).
Leaf IIb: 4 small brass feet. Epact tables for years 1627-1645 mared ‘EPACT IVLINI ANNO’ and ‘EPACTA GREGORI ANNO’. Lunar volvelle (brass disc missing).
Red, blue, black and green colours used. Hook fasteners missing.
(Suspension loop and ring. Compartment in side of leaf II for wind vane, cover missing; 1-2-2000).
Condition: fair (warped); incomplete (compass glass and needle, string gnomon, wind vane, fasteners, volvelle disc missing).
References
Events
Description
The Diptych dial is a common form of portable multi-function sundial. Diptych dials were made popular by the instrument makers in Nuremberg during the sixteenth and seventeenth centuries. They are usually made of ivory with brass fittings, and are often elaborately decorated. The name of the device derives from the Greek diptychos for a pair of folding writing tablets, which the instrument resembles.
Diptych dials consist of two leaves hinged together, with a string ‘gnomon’ stretched between the inner surfaces of the leaves for casting a shadow. To use the device as a sundial the lower leaf must be placed parallel to the horizon and the upper leaf must be at a right angle vertically to it. The gnomon must then be aligned with the meridian of the place where it is being used by using the inbuilt magnetic compass. Time can then be read from the horizontal or vertical dial by the location of the shadow cast by the string gnomon.
In addition to the horizontal and vertical dials, diptych dials normally carry a number of other features, such as equinoctial dials, windroses, tables of latitude for adjusting the string gnomon for different locations, epact tables, lunar volvelles for telling time at night by the moon, and various pin-gnomon dials for telling the time according to Babylonian or Italian hours, or for calculating the position of the Sun in the zodiac.
27/05/2009
Created by: Joshua Nall on 27/05/2009
FM:43265
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