An early 17th-Century German gilt-brass diptych sundial,

细节

An early 17th-Century German gilt-brass diptych sundial,
signed on the underside of the lid *M*P* [Markus Purmann] 1614, the top of the lid with decorative floral engraving around a volvelle with two apertures labelled AVFGANG and NI DER GANG revealing a circular punched hour scale graduated 3,4-,4,5-,5,-6,6,7-,7,-8,8-9,9 and again in reverse to 3, with two indexes labelled NACHTLENG and TAGLENG to a surrounding scale graduated 6-18-6, the dial used to determine the length of the day and the night in hours with the earliest sunrise at 3am, and the latest sunset at 9pm, giving a night of 6 hours, the underside of the lid with a volvelle labelled INDEX DIERVM AETTATIS LUNAE to determine the moon's age, the rim graduated 1-12 (x2), with an index to a scale of days in half day divisions 1-29½, and a surrounding scale graduated 1-12 (x2), labelled around the edge of the lid's interior SEPTENTRIO, ORIENT, MERIDIES and OCCIDENT, the base with sprung plummet support in the stylised form of two dolphins and a latitude indicator beneath the filed plummet for latitudes every 2° from 40° to 54°, the dial plate supported by a spring on the underside to adjust for these latitudes, the glass covered compass with beaten brass split retaining ring and blued-iron needle with brass cap, the compass bowl inscribed with a simple arrow, surrounded by hour scale 3-12-9, the edges of the case with floral decoration, the underside engraved with a TABULA LATITUDINIS REGIONUM with the names and latitudes of thirty-six European cities and towns (see below), with brass catch and turning hoop -- 2.11/16in. (6.8cm.) long

See Colour Illustrations

拍品专文

Tabula latitudnis Regionum

Augusta 48 Lundinum 52
Argentina 49 Mediolanu 45
Antuerpia 51 Monachu 48
Brixia 45 Marsilia 43
Bononia 45 Neapolis 41
Bronschuig 53 Norimberg 49
Colonia 51 Praga 50
Cracouia 51 Parisius 48
Compostella 44 Roma 42
Forentia 43 Ratispona 49
Ferraria 43 Sauone 43
Francopho 50 Tibigna 48
Gretza 47 Toletum 40
Gennua 42 Venetia 45
Hydelberg 50 Vienna 48
Hamiburg 54 Vuitemberg 52
Inspruch 47 Lubech 54
Luneberg 53 Genua 43

All of the letters and numerals on this instrument have been punched. In addition, the split ring retaining the compass glass has been made not from wire but from a beaten strip of brass, and the plummet has been filed to shape rather than turned. All these characteristics would imply that the instrument is the product of a small workshop which did not have a lathe.