Objekt 14
Equinoctial sundial (ring sundial)
Description
Ring sundials are among the most versatile portable sundials because they do not require a compass. They were made in large numbers of brass or, like this example by Johann Willebrand, silver. The two rings were twisted flat into each other for transport. For use, they were opened to 90° and hung on a thread. The outer ring has scales for setting the suspension eye to the correct latitude as well as polar altitudes, and the time is read on the engraved scale of the inner ring. Through the sun's ear, often designed as a flower, a spot of light falls on the hour scale of the inner ring. Thus, with this sundial, it is not the shadow that tells the time, but the light itself.
Object description
Manufacturer: Johann Willebrand (around 1658-1726)
Augsburg, 1st quarter 18th century.
Silver, engraved
Signature: Johann Willebrand in Augsburg
Bequest Marie Bachofen-Vischer, Basel
Inv. 1919.380.