Accession No
0051
Brief Description
ivory diptych dial, made by Jacob Karner, German, 2/4 17th Century
Origin
Germany; Nuremberg (Nürnberg)
Maker
Karner, Jacob
Class
dials
Earliest Date
1625
Latest Date
1650
Inscription Date
Material
ivory; metal (brass); rope (string)
Dimensions
67 x 101 mm; d (compass) 29 mm
Special Collection
Robert Whipple collection
Provenance
The association with the Whipple Collection is uncertain.
Inscription
Description Notes
Ivory with brass fittings (clasps all replacements.) Decorated on outside of tablets. Leaf Ia: 16 point windrose with 16 points marked ‘N, NNO, NO, ONO....’ and 32 points numbered 1 - 32 from E through S. Brass index, wind vane (a replacement ?); leaf pierced to show N point of compass (and house plumb bob?)
Leaf IIb: 4 small brass feet (2 replacements) table of epacts for 1627-1645, marked ‘EPACTA IVLIANI ANNO’ and ‘EPACTA GREGORI ANNO’ with lunar volvelle (central disc missing).
Leaf IIa: horizontal dial for 42˚, 45˚, 48˚ and 51˚; divided 4 - 12, 1 - 8 , numbered by 1, subdivided to 30 minutes. Inset compass with 4 cardinal points marked in Latin, N-S line offset for magnetic variation (lacks compass needle and glass). Two subsidiary dials each with pin gnomon and divided 10 - 22 for Italian hours and 2 - 14 for Babylonian hours, both numbered by 1. In the compass Jakob Karner’s mark ‘3’. Slot inside leaf to house wind vane. String gnomon (a replacement).
Leaf Ib: attachment points for gnomon marked with latitude. Dial for planetary hours and hours of day and night. Planetary hours divided 1 - 12, numbered by 1. Dials for hours of day and night marked by zodiacal symbol and divided 16 - 8 and 8 - 16, numbered by 1. Table of towns and latitudes; ‘VERONA 45, TORN 51 ....’ Markings in red and black.
fair/poor condition
missing compass and string
missing plumb bob
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:39768
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