Meridian columns on Wienerberg

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The meridian columns on the Wienerberg , also called Wienerberger Miren , were two target marks that no longer exist today for precisely setting up the instrument axis of the telescopes in the west-east direction in the old Vienna University Observatory . This Miren were on the Wienerberg , more precisely on the Boschberg , later favorites , the 10th  Viennese district .

Explanation

Meridian columns, also known as meridian monuments, are commonly known as those elaborately designed stone columns that mark meridians - the lines of equal longitude . The designation of Miren as a meridian column is rather unusual, but these adjustment pillars were called that on the Wienerberg when it was built.

Emergence

When the professor of astronomy Joseph Johann von Littrow (* 1781; † 1840) took over the management of the Vienna University Observatory in 1819, he procured the most modern equipment for this facility. The observatory, built under Empress Maria Theresia from 1753 to 1754, was located on the roof of the old Vienna University in Vienna I (Inner City) on Dr.-Ignaz-Seipel-Platz . Since Littrow did not receive any funding for the new building he wanted instead of the old one, the two old baroque observation towers on the roof were replaced by rotating domes for the meridian circle and the noon tube under his direction from 1825 to 1826 .

A fixed point far away was required for the daily check and readjustment. This could be the North Star - which of course was only possible when the night sky was clear - or a landmark such as a church tower or an artificial object on the horizon. This led to the construction of the meridian columns on the Wienerberg in front of the Favoriten line .

Localization and construction

Rother Hof in the upper center on the left; on the ridge to the left were the two mires

The first such stamp was a painted white rectangle on the north wall of Count Pfaffenhof's house , the so-called Rothen Hof (today Buchengasse  67). In 1826 two brick pillars were erected exactly in the south of the observatory at a distance of 4785.5 m (15140 Viennese feet). The location was the open field of the corridor in the upper Muhren on the plateau of the Wienerberg, actually the Posch or Boschberg, at that time - like the south of Favoriten in general - still undeveloped. A construction in the north of Vienna was not possible because of the very strong forest there at that time. The pillars stood on the western edge of the veil barracks, built later (from 1914) as a war school for the disabled, on the Favoritner Gewerbering No. 6.

The mires were 4.75 m high and about 4 m apart. This distance corresponded to the distance between the two telescopes of the observatory. On top of the pillars were pyramid-shaped stone slabs, each with an iron cross. The crosses had square openings in their crossbars with a side length of 10 × 10 cm, which the observatory used as fixing points.

On Littrow's order, the main instruments of the observatory were adjusted daily according to these miren. In his annals he wrote about it:

These squares [in the crossbar] projected into the sky at a not insignificant height above the natural horizon of the ground, and can be seen very sharply in clear weather.

A trigonometric survey of Vienna took place from 1834 to 1839 , whereby the western of the two mires was the southern fixed point in the trigonometric network.

Later story

The meridian columns developed into a popular excursion destination for the Viennese during the Biedermeier period . Nearby, at the former hunter's house on the Laaer Berg , Littrow's son and successor Karl Ludwig von Littrow (* 1811; † 1877) also built an observatory. Around 1835 the mires were marked directly south of the fortification brick loft, in 1863 the columns could still be seen in their place on a map, in 1872 only one of them was shown on a military lithograph at a distance of around 25 m from the original location of the western column pictured. This change of location could be related to the construction of the third observation dome on the roof of the university.

An unnamed contemporary witness wrote a memory sketch around 1925 that shows the two columns as they should have looked around 1875. He gave the height unchanged at around 4 m, but the distance from each other at 20 m. The crosses are clearly visible, behind them (on the eastern upper edge) two iron plates attached at an angle are drawn, the purpose of which can no longer be determined. When the new building of the university observatory on the Türkenschanze was completed in 1879 , the Miren on Wienerberg were no longer needed and were only noted on a city map from 1902 with the map symbol for wayside shrines. Later they were no longer recorded.

literature

  • Felix Czeike : Historical Lexicon Vienna . Vol. 4. Kremayr & Scheriau, Vienna 1995, ISBN 3-218-00546-9 .
  • Joseph Johann von Littrow: Annals of the kk observatory in Vienna , 4th, 8th, 9th and 20th parts, Vienna 1824, 1828, 1829 and 1840.
  • Walter Sturm: ... except for the line. Favorites on Wienerberg . Favoritner Museum Blätter No. 30, District Museum Favoriten Vienna 2004.

Individual evidence

  1. ↑ the horizontal tilting axis of a telescope around which the telescope rotates when tilting vertically (changing the elevation angle)
  2. ^ Czeike: Historisches Lexikon Wien , Chapter: Littrow, Joseph, Johann.
  3. ^ Littrow: Annalen der kk Sternwarte in Wien , pp. 4/9 and 26, 8 / 3-5 and 10, 9/4, 20 / 1-4.
  4. ↑ 1 Viennese foot = 31.61923 cm
  5. ^ Littrow: Annalen der kk Sternwarte in Wien , p. 4/9.
  6. ^ Littrow: Annalen der kk Sternwarte in Wien , pp. 20 / 1-4 (with a plan of the network).
  7. ↑ a b Sturm: ... except for the line , pp. 60-62 (with the sketch on p. 62).

Coordinates: 48 ° 9 ′ 52.5 ″  N , 16 ° 22 ′ 39.9 ″  E