Pawn ring
The peasant ring (also: simple sun ring or simple ring sundial ) is an elevation sundial that can be worn on the finger or, in a larger version, on a chain on the neck . He has been known since the 15th century ( Regiomontanus ).
Its dial is on the inner ring surface. The pointer is the image of the sun, which is created by means of a hole made in the ring. To read the time of day , the season ( declination of the sun) must be known. The inner ring surface is additionally provided with declination lines. These are circles around the ring axis.
To read the time, the pawn's ring is hung up on its external loop and turned around the vertical so that the light spot falls on the valid declination circle (see left figure).
A pawn ring or a simple sun ring can only be used at one pole height or one degree of latitude .
Newer versions consist of two concentric rings. The ring with the hole is set against the main ring according to the season (monthly scale) and the time of day is read on an hour scale that is valid all year round. Because this simplified method is not exactly exact, a rough scale consisting only of hours is used (see right figure).
literature
- Sundial Handbook , German Chronometry Society, Working Group Sundials, 2006, p. 74
- Helmut Sonderegger: Bauernringe , Deutsche Gesellschaft für Chronometrie, Yearbook 2006, pp. 165–174
- Fritz von Osterhausen: The great watch lexicon . Heel, Königswinter 2005, ISBN 3-89880-430-5
Individual evidence
- ^ Ernst von Bassermann-Jordan, Hans von Bertele: Uhren . Klinkhardt & Biermann, Braunschweig 1969.
- ↑ Reinhard Meis: The old clock, vol. 1 . Klinkhardt & Biermann, Braunschweig 1978.
- ↑ Helmut Sonderegger: Bauernringe , Deutsche Gesellschaft für Chronometrie, annual publication 2006, pp. 165–74
- ↑ Sundial Handbook , German Society for Chronometry, Working Group Sundials, 2006, p. 129
- ↑ Ralf Kern: Scientific instruments in their time . Volume 2. Cologne, 2010. p. 415