Gotha Observatory

The Seeberg Observatory in Gotha was one of the first own Sternwartenbauten Europe. It was built by Duke Ernst II of Saxe -Gotha -Altenburg according to the plans of the astronomer Franz Xaver von Zach. She was part of the overall project observatory Gotha, were among the other research institutes and a number of staff scientists.

1790, the Seeberg observatory was taken on the little Seeberg in operation. She served until 1839 as an astronomical observatory. First, with the most modern - mostly English - equipped instruments, it was considered as prototype of other observatories, such as the Göttingen observatory. Under Franz Xaver von Zach was a center of astronomical information. In 1798 the first European astronomers Congress was held here. From here, the first astronomical journals went to all countries.

Planning work

Zach was able to convince the Duke that towers and tall buildings are unsuitable for the preparation of telescopes and hit a walk- storey Sternwartenbau ago. As low site he recommended the Seeberg, a quarter of an hour's drive from the castle. Franz Xaver von Zach planned a massive observatory building in east -west orientation, offered the space to the installation of two mural quadrant, an instrument passages and the associated clocks. Observations should be done by masonry columns, which allowed an unobstructed view to the north or south horizon. In the middle of the building should rise above the entrance hall a small round tower with revolving dome, in which a whole circle should be placed. Two wings were intended as the residence of the astronomer and as a home for the staff, the guard and stables.

The calibration of the foundations took the Duke and Franz Xaver von Zach act jointly. The construction was entrusted to the architect Carl Christoph Gotha better.

The observatory building

There was a walk- Concrete (as Meridian Hall) with two perpendicular recognized residential and commercial buildings. About the observatory Zach wrote in 1789:

Zach was the pillar of the instruments in the bedrock substantiate and thus avoided the measurement error resulting from the oscillating components of higher buildings. The main building, the Meridian Hall was firmly joined from Seeberg Sandstone and corresponded to the original plans. In four rooms, the quadrant, the passages instrument of Ramsden with 2.40 m focal length, the astronomical clocks, including the sidereal clock by Arnold and the master clock by Mudge & Dutton, and many other astronomical and meteorological instruments were set up. In the dome there was a vertical circle of carry. The fourth room was heated and served as the only warmup astronomers.

The construction phase ranged from 1787 to 1789. Astronomer inhabited the eastern building with many rooms and chambers, in the western farm buildings, the service staff, a guard of three men, the horses and carriages were housed. The construction ended in 1789, the observatory was put into operation in 1790.

Location of the observatory: 50 ° 56 '2 " N, 10 ° 43' 41 " O50.93375555555610.728183333333


In this design, and this equipment, the Seeberg Observatory was the then most modern observatory in Germany and one of the most advanced research facilities around 1800. Several devices have been taken with the completion in operation, the passage instrument of Ramsden, the clocks of Mudge & Dutton, Arnold and Klindworth, smaller telescopes and a heliometer by John Dollond. Over time, the equipment advanced considerably. Duke Ernst II had for the construction cost 36 000 dollars and for instrumentation 20 000 dollars from his " casket " basis and attempts to back with a foundation of 40 000 thalers the maintenance of the observatory. The final equipment did not quite meet the above perspective Zach. A zenith telescope was not installed.

The base point of the passage instrument had the following coordinates:

Length: 10 ° 43 ' 51 "East Latitude: 50 ° 56' 05 " North

These values ​​were also used later on the national survey and were the starting point of a precisely measured base line to Schwabhausen. The Meridian stone on the Seeberg is no longer in the accurate position since the renovation of today's hotels.

The observatory under Zach's line

Zach's work

Zach lived as a bachelor eastern building that had a direct connection to the Meridian Room. He had a budget of two female and three male domestic servants, four horses, an orderly, a sergeant and three guards to secure the plant.

The fame of the observatory spread very quickly and the lively exchange of letters of Franz Xaver Zach's made ​​her a sought- visit destination of that astronomers. In 1798 it came to the " first European astronomers Congress" ( see below).

Other scientific achievements of the Seeberg Observatory under Zach's line was the rediscovery of the asteroids Ceres and Pallas, the establishment of a Astronomical Society and the advancement of geodesy in preparation of the Prussian land surveying. For this purpose a later repeatedly used geodetic base, the measuring section Seeberg Observatory - Schwab -hausen precisely defined.

The death of Duke Ernst II on April 20, 1804 first completed this fruitful work. Franz Xaver von Zach left as steward of the Dowager Duchess of Gotha and put 1806, the supervision of the Seeberg observatory down.

1806 Zach sent the last in his possession Observatories objects to Gotha, where they, like the other instruments were stored because of the threat of war in peace flintlock.

First European astronomers Congress

The famous French scientist Joseph Jerome de Lalande had expressed a desire to meet on the Seeberg with foreign colleagues, particularly with Johann Elert Bode in Berlin. Franz Xaver von Zach extended invitations to several colleagues, but some of them for fear of revolutionary French ideas were not approve the trip.

It met in 1798 about 17 European astronomers in the Seeberg Observatory to exchange ideas, demonstration of new devices and methods to proposals for new constellations. A joint excursion to the island mountain made ​​practical exercises possible. While the proposals for constellations were not appreciated, but the use of the metric system was considered and agreed a firmer cooperation. The latter was then in the founding of journals, as in Franz Xaver von Zach from 1800, published monthly correspondence for the transport of terrestrial and celestial customer expressed.

The meeting then went into the history of astronomy as the first European astronomers Congress.

The visit of Goethe

In the summer of 1801, Goethe visited the Seeberg Observatory from a long visit, which he described as " pleasant and instructive " and 1829 years of wandering processed in literature in his novel Wilhelm Meister.

Young Scientists

It was always just a real astronomer employed. Employees were seen as adjuncts, ie agents without proper relationship to the court. For these adjuncts emerged a number of important astronomers. So lived Johann Friedrich von beans Berger (1765-1831), who later became the observatory Tübingen headed, Tobias guarantees (1766-1834), who worked later as a teacher at the Gymnasium in Klagenfurt and from 1792 as a university professor, the observatory Vienna took over, as well as the Hungarian astronomer Johann Pasquich (1753-1829) partly for several years on the Seeberg. Particularly close to Johann Karl Burckhardt worked (1773-1825) in the science of astronomy. He later became director of the military school, and thus also the observatory in Paris. Johann Kaspar Horner (1774-1834) of Zurich made ​​later as an astronomer the world trip of Captain Adam Johann von Krusenstern with ( 1803-1808 ).

For Gotha training Bernhard August von Lindenau (1779-1834) was particularly important, since this this did in 1804 to succeed Zach. We should also mention the cartographic education and training Adolf Stieler (1775-1826) at the Seeberg observatory, which this enabled them to lay the foundations for the development of cartography in Gotha.

The successor Zach as head of the observatory

Bernhard von Lindenau

The work of the Seeberg observatory was initially continued by Bernhard von Lindenau, who worked as an adjunct there since 1801 and was appointed vice-director later. Lindenau came from Altenburg and was ducal Kammerrat.

In 1808 Bernhard von Lindenau from the now reigning Duke Augustus of Saxe -Gotha -Altenburg charged with the re-establishment of the observatory and appointed director of the facility. He was able to report in May 1808, the operational readiness of the scientific establishment.

Soon, however, structural damage became evident. 1810 had the tower will be demolished and in 1811 the two side buildings. They built a new residential building for the astronomer, and castellan an adjoint on the west side of Meridian hall. This building was stylistically matched to the main building, the observatory had been given a completely different appearance. Bernhard von Lindenau continued the astronomical work of the Seeberg Observatory continued successfully in 1810 and published his Venus boards, 1811 's Mars panels and 1813 panels of the orbit of Mercury. 1813, the observatory was occupied by the French and burned many of their papers. The devices were not damaged.

Lindenau was appointed in 1814 to the Adjutant General of the Grand Duke Carl August of Saxe- Weimar -Eisenach and went with this in Paris, where he was wounded in a duel, so he could not continue his ministry.

Friedrich Nicolai and Franz Encke

As an adjunct of the observatory in 1814 Friedrich Nicolai was appointed and promoted to Assistant Director. He remained until 1816 in Gotha, and then went on to Professor Mannheim. He was replaced by the former Royal Prussian artillery lieutenant Franz Encke.

Encke had studied as Nicolai and Lindenau in Göttingen in Gauss. So know the three astronomers and worked well together. As Lindenau came back to Gotha, remained another year joint research before he finally had to return to the Management Service. From 1816 to 1817 he was, together with Johann Gottlieb Friedrich von Berger beans in Tübingen, the magazine of astronomy and related sciences out. Later he published nor astronomical works.

Johann Franz Encke led the scientific work on. He was in 1818 appointed Assistant Director, while Lindenau was used as a curator. Encke calculated, the orbital period of the comet Pons as the shortest known orbital period ( Encke 's Comet ) and the solar parallax from the Venus passages 1761 and 1769, which had long validity.

Encke married Amalie Becker 1824, the daughter of the Gotha publisher and bookseller Rudolph Zacharias Becker, who published the writings of the Seeberg Observatory and the German national newspaper.

Despite the improvement of the physical and material equipment of the observatory by a Fraunhofer cal Heliometer and Ertel meridian circle Encke accepted the call as professor in Berlin. He stressed in a memorandum that the content in Gotha is not sufficient for obtaining a family. He followed in 1825, therefore the offer to take over the Berlin Observatory, and left Gotha.

Peter Andreas Hansen

Several astronomers recommended Peter Andreas Hansen as his successor. Hansen was a watchmaker from Tønder, but who had worked as an assistant Schumacher in Altona several years. In August 1825, he arrived in Gotha, where he still encountered Johann Franz Encke at the observatory. From an understanding cooperation developed for years. A compiled by Hansen inventory list was the amount of telescopes, instruments, watches and meteorological and geodetic instruments recognize that established the central position of the Seeberg observatory.

Hansen immediately began extensive observations, but also checked the condition of the equipment and gave the conservator the instructions. He himself, however, was bound by the instructions of the curator Carl Ernst Adolph von Hoff (1771-1837), who had been employed in 1826 as a successor to Bernhard von Lindenau. Hansen's focus was on the theoretical work. He became a master of celestial mechanics. Focus was on the movement of the Moon, for which he developed precise formulas. So were his instrument technical and celestial mechanics publications of these years.

Meanwhile, married and the father of several children, he suffered from the increasing decay of buildings on the Seeberg and was a private house in the suburb of Siebleber Gotha build. In 1839 he left the Seeberg.

Hansen had to check the old observatory on the Seeberg weekly. He put it firmly the steady decay and now demanded the construction of a new observatory, which corresponded to the legacy of Ernest II. He brought to a observations of colleagues who supported this project. Even Alexander von Humboldt turned therefore to the Gotha government.

1856 decided the Gotha parliament the new building of the Ducal observatory on the site of the former smithy using the material of the Seeberg Observatory (see observatory Gotha ).

Later used

1858 Meridian hall was demolished. The material was used for a new building observatories in the Hunter Street (see observatory Gotha ). The building was used until a fire in 1901 as a restaurant. The new building of the restaurant (1904 ) instead of the former observatory took only the name " Old Observatory ". The Gotha popularly commented at the time the building with the witty rhyme: " The Astronomy follows the catering industry. "


Today, two commemorative plaques remind outside of today's restaurant " Alte Sternwarte " to Duke Ernst II as the founder and Franz Xaver von Zach as the first operator of the Seeberg observatory. The so-called meridian stone was also obtained.