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Inventory no. 49364 - Epact entry

Epact number: 68192

Azimuth Dial

16th century; German
Stone and gilt brass; 178 mm in diameter

Main text

This unusual azimuth dial has its hour lines incised on a circular tablet of stone. The decorative gnomon is a ring which can be both slid against, and rotated about, a central pivot.

In use the gnomon would be first adjusted by sliding it so that its pointers indicated either the date or the sun's position in the zodiac. The ring would then be rotated to the direction of the sun when the southern pointer would indicate the time.

The instrument, which is constructed for latitude 49° 30', has no indication of maker or date, but the reverse side of the table has lengthy instructions in German.

Source museum: Museum of the History of Science, Oxford
Museum number: Inventory no. 49,364

Detailed text

This sundial consists of a circular tablet of (Solenhofen?) stone, with a gilt brass rim and three brass legs. The hour lines are surrounded by a circular band of incised, coloured and gilt foliate decoration. Within this band are inscriptions for three of the cardinal points: 'ORIENS', 'MERIDIES' and 'OCCIDENS'. At the north point is a biblical quote: 'ET ERVNT LVMINA, IN SIGNA, TEMPORA, DIES ET ANNOS. GENE: I.'.

For orientation of the dial there is a small inset compass (18 mm in diameter) whose bowl is marked for the meridian. Surrounding the compass is a circular zodiac scale in which each sign is represented by its symbol and is divided to 10 and 5 and numbered by 10. Flanking the zodiac scale is the inscription 'Ad Eleuationem Poli Gra: 49 Mi. 30'.

The hour lines are from 4 to 12 to 8, marked at one end of the declination lines with the names of the months from June to November, and with the corresponding length of the day, and at the other end of the declination lines with the months from December to May.

The gilt brass gnomon is free to slide on and rotate about a central pivot. Its base is a slot at either end of which is a pointer surmounted by a pair of decorative rearing horses. The horses support a thin ring which casts the shadow.

In use the gnomon is first set for the date using the southern pointer; alternatively the northern pointer can be used to set the sun's position in the zodiac using the zodiac scale around the compass. The gnomon ring is then rotated to point in the direction of the sun and the southern pointer indicates the time.

On the lower side is a lengthy account of the use of the instrument in German.

Provenance: Michel Collection; Billmeir Collection (57-84/114).

Stephen Johnston

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