Accession No
1712
Brief Description
diptych dial and nocturnal, Belgian, 1597 or 1599
Origin
Antwerp; Belgium
Maker
Class
dials
Earliest Date
1597
Latest Date
1599
Inscription Date
9
Material
metal (gilt brass); glass
Dimensions
length 98mm; width 76mm; depth 22mm; height when open 108mm
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. 1935-66.
Inscription
Description Notes
Gilt-brass diptych dial.
Leaf Ia: nocturnal. Outer calendar scale marked by month and by zodiac sign, subdivided to 1 day and 1˚ respectively (equinox at March 20th). Disc with 16 teeth and index arm, marked ‘hora vrsa major’, divided 4 - 12 - 8, numbered by 1, also marked ‘hora solis’, divided 4 - 12, 1 - 8 (for use as equinoctial dial). Hinged index arm marked ‘Vrsa major Anno 1597’ (7 engraved over a 9). Index arm with engraved decoraion; leaf outside the calendar scale decoratedwith symbolic representations of the 4 elements as wind-blowing putti ‘Terra,Ignis, Aer, Aqua’.
Leaf Ib: similar decoration, the putti titled ‘orient, uia hactia meridies, occidens, septentrio’. Outer calendar scale marked by zodiac. Volvelle for lunar age, divided 1 - 29 1/2, numbered by 1. Also marked 1 - 12, 1 - 12 for southern face of equinoctial dial. Latitude scale along edge divided [0] - 80˚, numbered by 10˚, subdivided to 5˚.
Leaf IIa; horizontal dial for 51˚ 31´ divided 4 - 12, 1 - 8, numbered by 1, subdivided to 15 minutes. Inset compass; N marked with an arrow. Decoratively engraved (see history file).
Leaf IIb: list of towns and latitudes headed ‘Eliuati poli gradi 52’ (see history file). Decoratively engraved (see history file).
On the right hand side of the lower leaf is a decorated latitude arm for the equinoctial dial. Compartment for gnomon on left side.
fair condition
missing string
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:39776
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