Objekt 10
Equatorial-ear sundial
Description
An eye sundial is a sundial with a sighting device that is rotated against the sun so that the light spot produced by a pinhole - an eye - strikes the mark on the dial. Philipp Matthäus Hahn (1739-1790) invented this particular type of table sundial in 1763. The invention consisted in the fact that instead of the gnomon shadow, the focused sunlight hits the opposite wall inner side with the time scale through two small holes in the wall parallel to the axis. Thereby, either the mean or the true local time could be read on the dial. Two hands indicate the hours in Roman numerals (I-XII) and the minutes in Arabic numerals. A larger number of this type of sundial was also made after 1763, many of which were made by the sons and employees Hahn employed in his workshops.
Object description
Manufacturer: Philipp Matthäus Hahn (1739-1790)
Echterdingen (Baden-Wuerttemberg), 1782
Wood, iron, brass
Physical Collection No. 133
Deposit Astronomisch-Meteorologische Anstalt of the University of Basel
Inv. 1960.23.