Canonical sundial

Fig. 1 canonical sundial, modern replica

Fig. 2 canonical sundial, NON in the afternoon

Fig. 3 canonical sundial, NON at noon

Fig. 4 canonical sundial, prayer times and temporal hours

Fig. 5 canonical sundial, prayer times and equinox hour N.

Canonical sundials (or canonical sundials) were mainly used in medieval monasteries as well as town and village churches to display the daily prayer times for the monastery inmates and the clergy looking after the churches, which is reflected in the naming.

Canonical sundials are a semicircular, segmented ornament attached to a south wall, sometimes also designed as a full circle. A horizontal bar in the center serves as a shadow projector. They are counted among the sundials , although they cannot be used to display the time evenly over the day and independent of the season. In the monasteries, a precise chronological order was of secondary importance. It was more important to keep the order of the prayer times beginning with sunrise.

history

A previous model of the canonial sundial was a wall sundial in ancient Egypt.

There were also specimens in Roman times , later are known from Armenia . From the 9th century on, Byzantine art and the Orthodox Church only knew the "semicircular south clock" for 800 years and initially saw it as an image of the "true sundial", i.e. the movement of the sun in the sky.

The widespread occurrence north of the Alps is a result of the work of the Benedictines in England and Ireland. Most of the canonial sundials are preserved in the British Isles . As a result of the missionary work of the Benedictines on the European mainland, many canonial sundials were created in France and northern Germany, for example .

Most of the names of the hours are taken from the Roman names of the temporal hours . The even distribution of prayers over the day, prescribed by Saint Benedict, changed in the late Middle Ages . The prayers were performed earlier in order to break the fast prescribed by Benedict earlier. The NON finally took the place of the SEXT at noon, the VESPER prayer took the place of the NON in the afternoon. On the clock in Figure 3, the letters N for NON and V for VESPER are engraved at noon and in the afternoon, respectively.

Comparison of the displayed prayer times with the hours of the day

The center of Figures 4 and 5 shows the dial of a canonial sundial (as in Figures 1 and 2). In the radial direction, half a dial is attached to a vertical sundial spider . The latter is the modern name for a sundial with a shadow stick mounted vertically on the dial. The time reading takes place at the intersection of the rod shadow with the currently valid date circle. You can see the difference between the "wanted" time of prayer and the actual time of day. It can also be seen that the difference is only serious when compared to the equinox , the bad judgment is only understandable from today's perspective.

literature

• Gustav Bilfinger: The Medieval Horen and the Modern Hours. A contribution to cultural history. Kohlhammer, Stuttgart 1892 (unchanged reprint: Saendig, Vaduz 1997).
• Arno Borst : Computus. Time and number in the history of Europe. Wagenbach, Berlin 1990, ISBN 3-8031-5128-7 ( Kleine Kulturwissenschaftliche Bibliothek 28), (previously, to a lesser extent, published in: Archiv für Erforschung des Mittelalters. 44, 1988, ISSN  0012-1223 , pp. 1-82 , online (PDF; 10 MB) ).
• Gerhard Dohrn-van Rossum : The story of the hour. Clocks and modern time order. Hanser, Munich et al. 1992, ISBN 3-446-16046-9 .
• Herbert Rau, Karlheinz Schaldach: Vertical sundials from the 6th to 14th centuries Century. In: Anton von Gotstedter (Ed.): Ad radices. Festival volume for the 50th anniversary of the Institute for the History of Natural Sciences at the Johann Wolfgang Goethe University in Frankfurt am Main. Steiner, Stuttgart 1994, ISBN 3-515-06327-7 , pp. 273-290.
• Karlheinz Schaldach: The ancient sundials of Greece. Mainland and Peloponnese. German, Frankfurt am Main 2006, ISBN 3-8171-1756-6 .
• Arnold Zenkert: The fascination of the sundial. Verlag Technik, Berlin 1984.

Individual evidence

1. ^ Herbert Rau, Karl-Heinz Schaldach: Vertical sundials of the 6th-14th centuries Century , Stuttgart 1994
2. ↑ Jürgen Hamel : Inventory of the historical sundials in Mecklenburg-Western Pomerania , Frankfurt am Main 2007 (Acta Historica Astronomiae, Volume 34)
3. ↑ Gustav Bilfinger : The medieval Horen and the modern hours , Stuttgart 1892