Astronomical clock in St. Nikolai (Stralsund)
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The astronomical clock in Stralsund's St. Nikolai Church is a monumental astrolabe clock from the 14th century . It was probably damaged in the 16th century, has not been open since then, but is the only watch of its kind that has been almost completely preserved in its original condition. The clockwork and the indicating parts have not been restored.
The Stralsund clock is the oldest mechanical clock in the world that has been preserved in its original state and is one of the oldest preserved furnishings in the brick basilica on Alter Markt, first mentioned in 1394 . It is in the choir of the church at the back of the high altar . A special feature of the watch is the self-portrait of its builder Nikolaus Lilienfeld , which is considered the oldest watchmaker portrait in the German-speaking area.
history
According to an inscription on it, the clock was completed on December 6, 1394 by Nikolaus Lilienfeld. It probably only lasted until the "church break" on April 10, 1525 during the Reformation in Stralsund.
In 1894, Gothic decorations on the dial were restored to the clock.
In August 1942, the clock face was relocated to the tower of St. Mary's Church in Grimmen to protect it from damage during the war. After the war she came back to the Nikolaikirche. The ornaments restored in 1894 were lost.
In 1994 the case was restored and the movement cleaned and preserved. Missing parts of the movement were not added for reasons of grandfathering and therefore the watch was deliberately not brought back into function.
description
The watch case
The watch case is square with a side length of about 4 meters. The round dial touches the case frame. The four wise men are depicted in the four corners :
- above left the Greek mathematician , geographer , astronomer , astrologer , music theorist and philosopher Claudius Ptolemy ; the banner reads: "ptolemeus Inferiora reguntur a superioribus" , in German "Ptolemaeus. The lower is directed by the higher. " ,
- Above right the king of Castile and León and king ( antagonist ) of the Holy Roman Empire , Alfonso X. of Castile with the banner: “Alfoncius Motus solis et planetarum in obliquo circulo est.” , in German: “Alfonsius. The movement of the sun and the planets takes place in an oblique circle. " ,
- Below left the Islamic scholar, doctor and astrologer Ali ibn Ridwan , known as Hali, with the slogan: “Hali Dies est elevacio solis super oricontem.” , in German: “Hali. The day is when the sun rises above the horizon. ” And
- Bottom right the Persian mathematician , astronomer and astrologer Albumacar with the banner: “albumacar Sapiens vir dominabitur astris.” , in German: “Albumasar. A wise man will rule over the stars. "
Windows are painted on the left of the narrow side walls; Nikolaus Lilienfeld, the builder of the clock, looks out of one.
The substructure
The watch case appears to be supported by a wide central console. This has a wide barred window, which may have been intended to accommodate a disc showing the date. Panel pictures are painted on the narrow side walls connecting to the stone pillars. The left picture shows a man pushing open a door and a banner with the Latin inscription "post deum omnium vivencium vita sol et luna" (German: According to God, the sun and moon are the life of all living); it represents the morning. The picture on the right shows a man who closes a door and a banner with the Latin inscription "matutinae imensa munera sed sepe male finiunt" (German: the day offers rich gifts in the morning, but often ends badly) ; it represents the evening.
The clock displays
The clock combines the sober display of the time and some related movements of celestial bodies. It is both a large clock and a clockwork powered astrolabe .
Big clock
It is a clock for equal ( equinox ) hours with a 2-by-12-hour count . The right and left halves of the outer hour ring with a dark blue background (diameter about 3.5 meters) are each set with gold Roman numerals from I to XII in Gothic minuscule . The narrower ring that adjoins the inside is divided into 72 sections, one for a third of an hour each. One of two long thin hands is the clock hand (hour hand; a minute hand did not yet exist in the Middle Ages). All other scale rings and markings following inwards are the dial of the astrolabe clock.
Astrolabe clock
The monumental astrolabe, which is additionally driven by the clockwork, is a moving model of the sky. With the “Baltic Sea Clocks” (Schukowski), the movement of the sun is in the foreground, which means that in addition to the equinox hours that have come into general use with the mechanical clock, the unequal temporal hours that have been used up to now are still displayed.
In an astrolabe, all the circles in the sky and the horizon circle are circles again in the picture. With the Stralsund astrolabe clock, the celestial sphere from the celestial north pole is mapped onto the horizon plane (so-called southern projection ). The south pole, hidden by the horizon image, is the center of the dial, which is surrounded by seven concentric circles. The outermost is the image of the tropic of Cancer , the middle one of the celestial equator (zodiac signs Libra and Aries ) and the smallest of the tropic of Capricorn . In between there are two by two darker circles as images of small circles that correspond to the other eight signs of the zodiac (two per circle), namely the circle of Gemini and Leo , the circle of Taurus and Virgo , the circle of Pisces and Scorpio and the circle of Aquarius and Sagittarius .
The wide scale ring, highlighted in green and divided into 24 sections between the Tropic of Cancer and the scales of the Great Clock, is not part of the images in the astrolabe. It only indicates 24 points of the compass, four of which are labeled in white: “meridies” (south), “oriens” (east), “septentrio” (north) and “occidens” (west).
The astrolabic image of the horizon is eccentric with its south direction closest to the center. Since the image is cut off outside the Tropic of Cancer, the northern part of the horizon circle is also missing. Its blackish interior represents the invisible area of the sky. Its eccentric position corresponds to the geographical latitude of Stralsund with "54 gd 25 m".
The height circles and azimuthal arcs above the horizon, which are common with astrolabes and also with some astrolabe clocks , were dispensed with in favor of the images of the temporal hour circles of the sun . Only these 13 arcs (two on the horizon arc) are drawn above the southern sky between the tropics. The twelve fields between them are used to display the twelve temporal sections of the clear day (between sunrise and sunset). The beginning of each field is marked on the outside with a Gothic number from 1 to 12 to designate the corresponding hour.
The moving celestial bodies represent the sun and moon with the help of two thin pointers. Individual stars are not shown on the Stralsund clock. Together with the pointers, only the image of the ecliptic circle rotates as the outer edge of an eccentric circular ring above the dial. This ring is set with the twelve signs of the zodiac, which mark the annual position of the sun (its ecliptical length ). It touches the Tropic of Cancer from the inside and that of the Capricorn from the outside and rotates clockwise a little faster than the hour hand, namely once every 23 hours and 56 minutes ( sidereal day ), while the hour hand revolves once every 24 hours ( solar day ) . The hour hand indicates the position of the sun at its intersection with the ecliptic circle. Since the hour hand rotates a little more slowly, the point of intersection moves slowly counterclockwise relative to the stars (one relative rotation per year). Above the temporal hour fields, the intersection shows the temporal hour of the day.
The thin hour hand also shows the current position of the sun or the temporal hour of the day. A second thin pointer shows the moon's movement. In about 29½ days it will lag behind the hour / sun hand by one revolution. When both hands face each other, it is a full moon, when they overlap, it is a new moon. Since the lunar orbit does not deviate far from the ecliptic, the intersection of the moon pointer with the ecliptic circle is also approximately the image of the moon.
The Baltic watch family
Manfred Schukowski summarizes the Stralsund Astronomical Clock and several similar clocks in churches in the Baltic Sea region to form the “Baltic Sea Clock Family”: All of them have a wooden clock case with several meters long front edges, which is attached at a height of a few meters between two inner columns of the church. Often - as in Stralsund - they take the place behind the high altar , with the dial facing the eastern outer wall of the church; Under the face of these clocks there are often wooden columns with a rotating date disc between them - in Stralsund there are neither, the columns are only painted on narrow panels.
literature
- Manfred Schukowski : Wonderful watches . Thomas Helms Verlag, Schwerin 2006. ISBN 3-935749-03-1
- Manfred Schukowski: Clocks from churches in Hanseatic times . In: Deutsche Gesellschaft für Chronometrie , annual publication 2009. pp. 69–83.
Individual references / comments
- ↑ Manfred Schukowski : The Astronomical Clock in St. Marien zu Rostock . Langewiesche successor and Köster publishing house, Königstein / Taunus, 1992. p. 12: Overview table of the "Ostsee-Uhrfamilie"
- ↑ Manfred Schukowski : Wunderuhren , Thomas Helms Verlag, Schwerin 2006, ISBN 3-935749-03-1 , p. 111: The clock is "unique" because it "has remained unaltered and almost completely in its external Gothic shape" and " their clockwork [...] is available without any addition from a later period ” .
- ↑ It is sometimes speculated whether the clock could have been damaged by a lightning strike on March 17th, 1480. Such lightning damage to public clocks could usually happen if the clocks had pointer mechanisms on the church tower or other high places in the church building, which - similar to a lightning rod - offered a target. In the case of the Stralsund astronomical clock, however, there is no indication that the clockwork could ever have driven such an additional hand mechanism. A lightning strike to the location of the clock is hardly imaginable.
- ↑ The temporal hour lines are not exact, but are circular to a very good approximation. Cf. Ernst von Bassermann-Jordan (editor): The history of time measurement and clocks ; Volume 1: Joseph Drecker: Theory of Sundials ; Chapter II: General Nature of the Hour Lines, De Gruyter, 1925, pp. 12-20
- ↑ Manfred Schukowski : The Astronomical Clock in St. Marien zu Rostock . Langewiesche successor and Köster publishing house, Königstein / Taunus, 1992. pp. 9–13.
