Accession No
1686
Brief Description
ivory diptych dial, by Nicolaus Müller, Germany, 1649
Origin
Germany; Nuremberg (Nürnberg)
Maker
Müller, Nicolaus
Class
dials
Earliest Date
1649
Latest Date
1649
Inscription Date
Material
ivory; metal (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. 1935-40.
Inscription
‘NICOLAVS MILLER 1649’
Description Notes
Rectangular ivory diptych dial with brass fittings.
Leaf Ia: 16-point compass rose with points named. Foliage decoration picked out in red and blue-black; 4 small feet; pierced to show N point of compass.
Leaf Ib: vertical dial with pin gnomon for day length ‘quantitas diei’, divided 8 - 16, numbered by 1, with zodiacal symbols ‘signa zodiaci’. Attachment points for string gnomon every 3˚ between 42˚ and 54˚. List of towns and latitudes (see history file).
Leaf IIa: horizontal string-gnomon dial ‘hora ab meridie’ with hour scale divided 4 - 12, 1 - 8, numbered by 1, subdivided to 30 minutes; scales for every third degree of latitude between 42˚ and 54˚. Marked ‘soli deo gloria’. Inset compass with cardinal points marked. Pin gnomon dial for Italian and Babylonian hours, divided 10 - [22] and 2 - 14, numbered by 1.
Leaf IIb: four small feet; foliage decoration picked out in red and blue/black. Lunar volvelle with stamped gilt-brass rotatable disc.
Compartment for wind vane.
Maker’s mark - crown
fair condition
missing 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:39774
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