Accession No


Brief Description

ivory diptych dial, made by Paul Reinmann, 1611


Nuremberg (Nürnberg); Germany


Reinmann, Paul



Earliest Date

Jan. 1, 1611

Latest Date

Dec. 31, 1611

Inscription Date


ivory; metal (brass, steel); glass; rope (string)§


width 70mm; depth 96mm; height 16mm (closed)

Special Collection

Holden-White collection


On loan from The Fitzwilliam Museum, University of Cambridge. Donated by Charles Holden-White to the Fitzwilliam Museum. Holden-White collection no. 1935-43.


Description Notes

Leaf Ia: wind rose with 32 points, divided to 1/4, numbered by 1 with 32 at East; 16 points named. Brass index arm with finger pointer (lacks wind vane). Leaf pierced to show N point of compass.
Leaf Ib: vertical dial with pin gnomon for unequal hours, divided 1 - 12, numbered by 1, marked ‘planeten stvndt’; another pin gnomon dial for length of day divided 8 - 16, numbered by 1, and marked by zodiacal symbol. Attachment points for string gnomon for latitudes 54, 51, 48 and 42. Table of towns and latitudes (see history file).
Leaf IIa: horizontal dial, divided 4 - 12, 1 - 8, numbered by 1, subdivided to 15 minutes, with 5 circles of calibrations for 54, 51, 48, 45 and 42˚ N. Central inset compass (needle not original). Decorative leaf pattern in corners. Horizontal dial with pin gnomon for Babylonian hours, divided 2 - 12, numbered by 1. Similar one for Italian hours, divided 10 - 22, numbered by 1. Between these two a vignette of a putto seated beneath tree with right shoulder on skull, left hand on sand glass.
Leaf IIb: lunar volvelle with gilt-brass rotatable index disc (stamped). Table of epacts for both calendars. 4 brass feet on leaf and maker’s mark (crown).
Compartment for wind vane in leaf II.

fair condition, ivory very discoloured on bottom
missing plumbob


Joshua Nall; ‘Copycat sundials?’; Explore Whipple Collections online article; Whipple Museum of the History of Science; University of Cambridge; 2020:


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.
Created by: Joshua Nall on 27/05/2009


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