Accession No
1696
Brief Description
ivory diptych dial; made by J. Tucher; 2/2 17th century
Origin
Nuremberg (Nürnberg); Germany
Maker
Tucher. Joseph
Class
dials
Earliest Date
1650
Latest Date
1700
Inscription Date
Material
ivory; metal (brass, steel); glass
Dimensions
width 67mm; depth 110mm; height 14mm (closed)
Special Collection
Holden-White collection
Provenance
On loan from The Fitzwilliam Museum, University of Cambridge. Donated by Charles Holden-White to the Fitzwilliam Museum. Holden-White collection no. 1935-50.
Inscription
Description Notes
Rectangular ivory diptych dial with brass fittings.
Leaf Ia: 32-point wind rose divided 1 - 32, numbered by 1; 16 named points; 8 named winds. Brass index in form of pointing hand. Leaf pierced to show N point of compass. Representations of 4 winds - putti heads blowing in the corners of the leaf.
Leaf Ib: vertical dial with pin gnomon (missing) for Babylonian and Italian hours, divided 2 - 10 and 13 - 23 respectively, numbered by 1. Also associated scale for length of day and night, divided 8 - 16 and 16 - 8, numbered by 1; marked by zodiac symbol. Beneath this dial are the attachment points for the string gnomon (missing) for 54˚, 48˚ and 42˚ N; vignette of a village; list of towns and latitudes (see history file).
Leaf IIa: horizontal string-gnomon dial with 3 scales for 54, 48 and 42˚ N, divided 4 - 12, 1 - 8, IIII - XII, I - VIII and 6 - 12, 1 - 6 respectively; each numbered by 1 and subdivided to 30 minutes. Inset compass with 4 cardinal points named; offset 5˚E of North for magnetic variation; four winds; maker’s mark (bird flying). At lower end of leaf a scaphe dial for Italian hours divided 10 - 23, numbered by 1. Corners of leaf decorated with leaf motif.
Leaf IIb: lunar volvelle. Brass volvelle disc with index. Also table of epacts for both Gregorian and Julian calendars (but marked incorrectly with the values for the Gregorian calendar given as those for the Julian calendar and vice versa).
fair condition
missing string and plumbob
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:39777
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