Parapegm
A parapegma ( Greek παράπηγμα "board", "calendar") is an ancient plug-in calendar that the Greeks associated with weather forecasts based on Babylonian astronomy .
origin
The heliacal and acronic rising and setting of the most important constellations as well as individual conspicuous stars were noted on the calendar made of stone . The dating was based on the Babylonian zodiac , in which the cycles were calculated from the difference in the rising and setting.
technology
Parapegms were made in stone or in the form of a scroll with holes drilled for each day of the year. These contained tablets with names of months and day numbers from the civil calendar. So you could determine the season of the civil date.
In a broader sense, the dial of an astronomical clock , on which the position of the sun was marked by an inserted peg, is also called a parapegma.
Further development
Euktemon expanded the Babylonian plug-in calendar with weather forecasts. Since the parapegms for each day contained the sun positions and star phases in combination with weather changes, typical weather conditions for zodiac positions of the sun or for star phases could be derived.
According to Geminos , they were set up purely empirically. However, he himself expressly rejects a causal connection between weather and star phases.
literature
- Kurt von Fritz : Basic problems in the history of ancient science. de Gruyter, Berlin et al. 1971, ISBN 3-11-001805-5 .
- Jürgen Mau: Parapegma. In: The Little Pauly (KlP). Volume 4, Stuttgart 1972, Col. 505 f.
- Albert Rehm : Parapegmastudien (= treatises of the Bavarian Academy of Sciences Philosophical-Historical Department.. NF 19, ZDB -ID 9,557,453 ). With an appendix Euktemon and the book De signis. Publishing house of the Bavarian Academy of Sciences, Munich 1941.