Accession No


Brief Description

astronomical compendium, by Charles Whitwell, English, 1604 [with modern repairs]


England; London; Strand


Whitwell, Charles



Earliest Date

Jan. 1, 1604

Latest Date

Dec. 31, 1604

Inscription Date


metal (gilt-brass, steel); glass; paper


length 87mm; breadth 65mm; thickness 27mm

Special Collection

Holden-White collection


On loan from The Fitzwilliam Museum, University of Cambridge. Donated by Charles Holden-White to the Fitzwilliam Museum. C. Holden-White collection.


‘Charles Whitwell’ (equinoctial dial)
‘1604’ (leaf Ib)
‘1975 [logo]’ (reverse of latitude arc)

Description Notes

astronomical compendium, by Charles Whitwell, English, 1604 [with modern repairs].

Gilt-brass circular case with suspension lug and shackle.
Leaf Ia: nocturnal. Date scale divided to named month, numbered by 10 days, subdivided to 1 day. Volvelle disc with index and hour teeth; hour scale divided I - XII, I - XII, numbered by I, subdivided to 30 minutes. Central sighting volvelle disc with index and slight sighting line.
Leaf Ib: tables of ‘prime’, divided 9 - 19, 1 - 8, numbered by 1; ‘epact’ numbered 9, 20, 1 ... and the date ‘1604’.
Opening of leaf 1 causes a semicircular segment to be erected. this supports the hour ring of an equinoctial dial, divided I - XII, I - XII, numbered by I, subdivided to 30 minutes; southern side divided VI - [XII], I - VI, numbered by I, subdivided to 30 minutes. Latitude arc and gnomon are replacements (see history file). Latitude arc divided [6]-90˚, numbered by 10˚, divided to 1˚.
Leaf IIa: compass with hand-coloured engraved paper card; 32-point rose; fleur-de-lys for North; degree scale divided [0] - 90˚ - [0] - 90˚ - [0], numbered by 10˚, subdivided to 2˚. Blued steel needle.
Leaf IIb: lunar volvelle. Hour scale divided I - XII, I - XII, numbered by I, subdivided to 30 minutes. 32-point wind rose with 16 named points. Volvelle disc with lunar age divided 1 - 29 1/2, numbered by 1, subdivided to 1/2 day. Lunar phase diagram.

Condition: good; incomplete (replacement gnomon and latitude arc added to instrument in 1975).

[NOTE: On 14/07/2015 XRF analysis was conducted on this instrument. Results and analysis are given in the ‘Notes’ field.]


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


An astronomical compendium is an instrument that carries numerous devices for telling the time and performing astronomical calculations. Many compendia were made in the German lands in the late 16th and early 17th centuries. They are often beautifully engraved in gilt brass. Typically such compendia carry a sundial, various lunar and solar volvelles, a compass, tables of latitude, and a perpetual calendar.

Two characteristics are typical of the construction of these instruments: first, they were often made as lavishly as possible; second, they are ingeniously constructed, with as many instruments as possible filling the available space. Each plate of the compendium is known as a 'leaf', and carries a different device. Most of the instruments on a compendium are used to simplify astronomical calculations. Many compendia have volvelles—rotating discs that show the phases of the Moon, the positions of planets, and other such phenomena.

Almost all compendia have at least one form of sundial. These are often adjustable for use in different places, and are accompanied by lists of the latitudes of major cities around the world. Sometimes these lists are obviously functional, including various towns and major ports, but often they are more fanciful, including places such as Babylon, Alexandria, Moscow, Cuba, Constantinople, and Nineveh (an important ancient city in Assyria). Like the gilt decoration and detailed engraving, these were intended to show the wealth and status of the instrument's owner.

Some compendia also carry stereographic projections. These are multi-purpose maps of the heavens, allowing many astronomical calculations to be simplified. Using these, people could determine the time of sunrise and sunset, and the position of the Sun in its annual (apparent) motion through the sky.
Created by: [Adapted from Boris Jardine’s 2008 Explore article] on 19/12/2013


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