Butterfield-type Pocket Sundial

Astronomy

Accession Number: 2019.ast.260

Description:

This is a small sundial. It consists of an elongated octagonal face with circular compass set towards one end of the base. The compass is covered with a glass cover, has a freely rotating central needle and cardinal directions engraved in Latin denomination on the base, alongside a fleur-de-lis.

Standing vertically on the face of the instrument is an triangular metal piece, the gnomon. This is hinged at the base so it can be laid flat. On one side there is engraved a small arced scale labelled from 40 to 60, and on the other a floral pattern. On both sides there is a small metal piece in the shape of a bird, where the bird’s beak is operating as a pointer on the scale.

Engraved on the surface of the octagonal face are a set of concentric scales, two of which are labelled with Roman numerals, indicating hours of the day. Between these there is a scale labelled in Arabic numbers, from 4 to 12 (at the gnomon) and then 1 to 7; these roughly align with the Roman numerals. Small numbers engraved at the ends of each of these, “40” “43” “45” “49”, indicate differing latitudes.

On the rear of the instrument, there is a small rod with a rounded ended that enables the instrument to sit on a flat surface. Near to this there is a small flat of metal with a screw through it. Engraved on the rear of the face and the compass base there are the names of a number of European cities and their respective latitudes.

Alternative Name: Butterfield-type Sundial

Primary Materials:

Metal: Copper Alloy, Metal: Blued Steel, Glass

Markings:

Engraved on the octagonal face: “Delure
Paris”

Engraved on the rear: “Hambourg 53 Bruxelles 51 Londres 51
Calais 51 Lisbon 51 Liege 51
Paris 49
Brest 48
Rennes 48
Orleans 48
Marseilles 43
St Malo 48
Vienne 48
Genes 44
Rome 42
Lion 46
Dijon 47
Rouen 40
Toulon 43
Mantoue 43
Milan 46
Madrit 40
Turin 45
Pau 43”

Function:

This instrument was designed to be a portable tool that would permit the user to tell the time by shadows cast by the sun. The compass would assist with correctly orienting the instrument. The different scales are labelled to indicate different latitudes (for Europe), which enabled accurate usage.

Condition:

Excellent: The metal face of the sundial is somewhat oxidized and shows a rainbow-like effect over part of its surfaces. The hinges of the gnomon are in very good condition and the compass is functional and its glass cover intact.

Manufacturer: Jean-Baptiste-Nicolas Delure, Paris

Date of Manufacture: 1700-1736

Provenance:

This instrument was acquired as an antique by Reynold K. Young, former Director of the David Dunlap Observatory (1935-1946), likely as a display object. Since, it has been either on display at the department or in storage at the David Dunlap Observatory in Richmond Hill, or at the Department of Astronomy and Astrophysics building on the St. George Campus at the University of Toronto.

Additional Information and References:

Information about sundials of this type can be found at compassmuseum.com. [17/10/19]

Information about the maker of this instrument was retrieved at adlerplanetarium.org. [17/10/19]

Historical Notes:

According to information stored with the object: “An adaption of the horizontal dial which is supposed to have been introduced by Michael Butterfield, an Englishman who worked in Paris from 1685-1724, the Butterfield dial is both portable and universal.”