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Inventory no. 81528 - Epact entry

Epact number: 25615

Diptych Dial

Signed by Georg Hartmann
Dated 1562; Nuremberg
Ivory and brass; 88 x 91 x 17 mm

Main text

Unlike most ivory diptych dials, this example does not include a horizontal string gnomon dial and has a polar dial on the outer side of the upper leaf. The polar dial is held by a cherub standing on a grid. Its pin is kept in a special compartment on the bottom edge of the lower leaf.

The inner sides are extensively decorated with coloured geometrical motifs.





Source museum: Museum of the History of Science, Oxford
Museum number: Inventory no. 81,528



Detailed text

The outer side of the upper leaf has a polar dial held by a cherub standing on a grid. The dial has hours marked from 5 to 7 and the sun declination is indicated by the symbols of the zodiacal signs. A star mark is in one of the squares of the grid where the cherub stands. A letter 'M' is marked at the bottom and there is a later inscription 'Polare Astronomica' written in black ink.

The inner side of the upper leaf is extensively decorated in red and green with geometrical motifs and is inscribed '|star| GEORGIVS HARTMAN |star| |star| |star| |star| NORENBERGE |star| FACIEBAT |star| |star| ANNO |star| DOMINI |star| M |star| D |star| LXII |star|'. Below the inscription is a pin gnomon dial (pin missing) with a sun effigy in the centre and common hours marked from 5 to 12 to 7. In the spandrel spaces are cherub heads, and on the right-hand side is an unequal scale of latitudes marked from [0°] to 70°, divided to 2° and numbered by 10°.

The inner side of the lower leaf has a compass (glass and needle missing) with eight winds named 'TRAMONTA', 'GRECO', 'LEVANTE', 'SIROCHO', 'OSTRO', 'LEBECHIO', 'PONENTE', 'MASTRO'. Surrounding the compass is a calendar scale with the names of the zodiacal signs coloured alternately in red and green, with each sign divided to 2°, numbered from 10° to 30° by 10°. The spandrel spaces are decorated with eight-pointed stars and the names of the cardinal points, and on the right-hand side is the brass arm, decorated with a geometrical motif, for adjusting the latitude. On the borders is the same geometrical decoration as in the upper leaf, typical of Hartmann. On the bottom edge of the leaf is a compartment for stowing the pin, and on the outer side of the lower leaf is a table with 34 towns and their latitudes.

See P. Gouk, The Ivory Sundials of Nuremberg 1500-1700 (Cambridge, 1988).

Ilaria Meliconi

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