Wind direction transmitter
A wind direction transmitter, usually made of rust-resistant metals , also known as a wind vane , weather vane or, to a limited extent , anemoscope , is a display instrument for determining the wind direction . It is based on the fact that a movable measuring element aligns itself with the dynamic pressure of the wind .
A wind direction transmitter can be viewed as a static system with only one mechanically stable state of equilibrium . The flag surface, which is asymmetrically attached to the axis of rotation and on which the wind exerts a torque when it is not aligned parallel to the wind direction, serves as the "input element" . The weather vane, in turn, serves as the "output element", as its orientation in the wind corresponds to its direction (see also directional stability ).
The oldest surviving weather vane is known from ancient Greece . The architect Vitruvius provided a description of the weather vane on the Tower of the Winds in Athens . The around 100 BC The octagonal tower, built in BC, had a figure of the sea god Triton on the tent-like tower roof , whose tail was aligned with the wind.
In Europe, ship masts were provided with metal or fabric wind flags from the 8th century , several of which have been preserved from the North and Baltic Sea areas ( ship flag from Söderala , ship flag from Heggen , ship flag from Källunge and ship flag from Tingelstad ).
For the European mainland a use can only be assumed from the 11th century, but early original weather vanes are only from the 15th / 16th century. Century preserved. In German-speaking countries, they were used in particular on town halls, palaces, castles, churches and town houses. Weather flags were not only used for short-term weather forecasting, but were also important as house and protective symbols. In some European countries (France, Sweden) the use of weather flags was reserved for the aristocracy and required royal approval.
According to a description from 1728 in Grimm's German dictionary , the weather vane as a wind vane is "a sheet of metal in the form of a rooster or a flag, which is placed on high buildings on a straight upward iron rod, whose ... movement shows where the wind is." . In the course of the development of lightning protection systems , the use of weather vanes experienced a first heyday in the 18th century, although in the Age of Enlightenment it was increasingly recognized that determining the wind direction alone is not sufficient for weather forecasting. In the 19th century, weather flags lost their importance, because on the one hand a finer and wind-independent method of weather forecasting was developed, primarily through the spread of the barometer , and on the other hand people became less weather-dependent in their way of life and work, for example due to progressive urbanization and industrialization .
Nevertheless, between around 1870 and 1920, in the course of rapid city growth, there was a renaissance in the use of weather vanes, which now also adorned houses and factories. Contrary to their previous function, they were now mostly used as house brands and ornaments . The motifs used mostly contained a coat of arms, a monogram, a symbol or a year and referred to the house or its owner. The mass use was forced by industrial production.
Today, weather vanes are primarily used for monument protection with decorative and informal significance.
In the simplest case, a flag can serve as a wind direction transmitter . In addition, windsocks are often used in air and road traffic to indicate cross winds. These can also provide rough information about the wind direction and strength.
In addition to textile weather flags, there are also wind direction indicators made of metal or plastic. Since technically the shape of a wind vane is not as important as its weight, many forms of wind vane exist. Wind direction indicators are often combined with compass roses, which allow easy reading of the compass or main wind direction.
Probably the largest weather vane is in Montague (Michigan, USA). It is 14.60 m high and 4.30 m long. Their weight is almost two tons.
Clickers are wind direction indicators on ships. Wind indicators made of plastic or canvas are mostly used on sailing boats. On ocean going sailing yachts , wind vanes attached to the stern are also used to control wind control systems.
One of the most widespread wind flags is the "weather cock", which can be found on many church towers or house roofs. The first known mention of a weathercock comes from the 9th century. Bishop Rampertus of Brescia had one cast out of bronze in 820 and had it installed on the tower of the Church of San Faustino Maggiore .
Weather cocks exist both as paper cut models and as sculptures. This can still be found today in many churches. The reason is probably the biblical passage in which Jesus prophesies to the apostle Peter : “Before the cock crows, you will deny me three times” ( Mt 26.75 EU ), which Peter said after the gospel report after Jesus was arrested out of fear Persecution also did three times. When the rooster crowed, he remembered this prophecy, was very ashamed, and then proclaimed the new faith until he was martyred . The rooster was therefore a warning not to turn according to the wind, but to follow the Christian faith faithfully like Peter in his further life.
In addition to this meaning, the rooster was also used as a symbol of Christ. The first evidence of this use is the diary Liber Cathemerinon by the late antique Christian poet Prudentius . Just as the rooster announces the end of the night and the beginning of the day and wakes people up, so, according to these interpretations, Christ conquers the night of sin and death and awakens people to Christian faith and eternal life.
The Old St. Alexander Church in the Lower Saxony municipality of Wallenhorst is a specialty . It carries a hen on its spire . According to legend, Charlemagne had this church built on the remains of the pagan temple in 772 after his victory over Wittekind and put a golden hen on top as a sign that they were hatching more churches in the region.
Today weather cocks are mainly installed as wind chimes and roof decorations , but still occasionally because of this religious significance.
In his poem The old tower cock , Eduard Mörike set a literary monument to the weather cock in Cleversulzbach .
Gallery - Weather vanes in history
Tower of the Winds with weather vane figure of the sea god Triton (around 100 BC)
Söderala ship flag from the Viking Age
Weather vane from the Königsberg Castle Tower (1686)
Weather vane of the Salsitz winery in the Burgenland district (1699)
St. Paulin Trier : Weathercock on the tower
Weather vane of the Hermannschacht briquette factory in Zeitz (1881)
Weather vane on the tower of St. Benedikt (Lankwitz) (1968)
Weather vane by Christoph Weihe on the church in Nietleben 1999
Weather vane in Domnitz Jörg-Tilmann Hinz 2008
Way cross with weather vane near Frittlingen
An angel figure as a weather vane on the Cathedral of Tolmezzo , Italy
Replica of the Seville Cathedral weather vane used in 1999-2005 while the original was being restored.
- The author Clemens Hellmut Pötz from Monheim am Rhein († 2001 at the age of 87) made in the years prior to the publication of his book Wetterfahnen, according to his own statements, “several hundred weather vanes that are now moving in the winds of all continents.” His book from the 1983 was the first comprehensive German-language publication on the subject of weather vane.
- The Museum am Dom Trier received from 80 regional and national steeple weather cocks existing collection of psychology professor Günther Reinert (1928-1979) from Trier, which they had collected from 1974 until his untimely death in 1979 in the summer 2012th Most of the roosters come from places in the Trier region, the Eifel and the Hunsrück; about a quarter comes from France. A selection has been on view in the permanent exhibition in the new building of the museum since November 2012.
- Günter Blume: In wind and weather - on towers and roofs - weather vanes. Leipzig 1996, ISBN 978-3-930694-15-0 (120 pages).
- Siegfried Börtitz: Old weather vanes. Verlag Seemann, Leipzig 1991, ISBN 3-363-00521-0 (96 pages).
- Siegfried Börtitz: Weather vanes between Dresden and Saxon Switzerland (= series of publications by the Pirna City Museum: Historical and local history articles from Pirna and the surrounding area , issue 8). Pirna City Museum , Pirna 1994, ISSN 0323-7516 .
- Heidi Gansohr, Alois Döring: Church taps . Unchanged reprint of the 1984 edition, Cologne / Bonn 1987, ISBN 978-3-7927-0800-2 (140 pages).
- Clemens Hellmut Pötz: Weather vanes - 280 historical and modern examples - With instructions for self-construction. Munich 1983, ISBN 3-7667-0664-0 (100 pages).
- Helga Stein: Where the wind blows from ... - The collection of wind vanes and weather cocks from Hildesheim master locksmith Heinz Tostmann. 2nd, revised edition. Hildesheim 1998, ISBN 978-3-8269-5021-6 (156 pages).
- Ute Ströbel-Dettmer: Twisted with the wind - weather vanes in color pictures by Udo Haafke and texts by Ute Ströbel-Dettmer. Freiburg im Breisgau 1987, ISBN 978-3-89102-181-1 (72 pages).
- Hans Christian Andersen: Hofhahn and Wetterhahn. (Fairy tale about a farm cock and a weather cock).
- Walter Pannike: The weathercock of the village church in Riehen. In: Yearbook z'Rieche. 1993 (About weather vanes).
- ↑ wetterhahn, m. . In: Jacob Grimm , Wilhelm Grimm : German Dictionary . Hirzel, Leipzig 1854–1961 ( woerterbuchnetz.de , University of Trier).
- ↑ Old St. Alexander Church in Wallenhorst ( Memento from February 12, 2008 in the Internet Archive ).
- ↑ Figure from http://www.zeno.org/Meyers-1905/A/Anemomēter ; it is the combination of weather vane and wind plate
- ↑ Chronicle 2001. Monheim am Rhein , accessed on January 26, 2020 (anniversary of the death of Clemens Hellmut Pötz).
- ^ Foreword, page 7 in: Clemens Hellmut Pötz: Weather flags - 280 historical and modern examples - With instructions for self-construction. Munich 1983, ISBN 3-7667-0664-0
- ^ Church taps - The Günther Reinert Collection. Diocese of Trier , accessed on January 26, 2020 (under Museum> Collections / Selection of works> Church taps).