Accession No
1683
Brief Description
ivory diptych dial, by Leonhart Miller, German, 1649
Origin
Germany; Nuremberg (Nürnberg)
Maker
Miller, Leonhart
Class
dials
Earliest Date
1649
Latest Date
1649
Inscription Date
1649
Material
ivory; metal (brass, gilt brass, steel); glass; rope (string)
Dimensions
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. 1935-37.
Inscription
‘LEONHART MILLER 1649’
Description Notes
Leaf Ia: 16-point wind rose with central sun motif. Full diameter index in gilt brass, arrow-shaped; brass wind vane. Foliage decoration. Pierced to show North point of compass.
Leaf Ib: pin gnomon dial for length of day marked ‘QVANTITAS DIEI’, divided 8 - 16, numbered by 1, and also marked with zodiacal symbol. Vertical dial with string gnomon for 50˚ N, divided VI - XII, I - VI, numbered by I, subdivided to 15 minutes; representation of the sun.
Leaf IIa: horizontal dial divided 4 - 12, 1 - 8, numbered by 1, subdivided to 15 minutes. Inset compass with cardinal points marked and the four winds shown; also maker’s mark - fleur-de-lys; offset for magnetic variation 5˚E of N with later and cruder marking at 23˚W. Horizontal dial with pin gnomon for Italian and Babylonian hours, divided 10 - 22 and 2 - 14, numbered by 1.
Leaf IIb: four brass feet. Foliage decoration. Lunar volvelle with stamped gilt brass volvelle disc. Maker’s mark stamped twice at hinge end.
Compartment for wind vane in side of leaf.
fair condition, small cracks
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:39755
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