Category of Astronomical Heritage: tangible immovable
Observatory Halle an der Saale, Germany

Description

Geographical position

Observatory Halle an der Saale, Botanical Garden, Große Wallstraße, Halle (Saale), Germany

Location

Latitude 51.489065° N, longitude 11.959344° E, Elevation ...m above mean sea level.

IAU observatory code

Description of (scientific/cultural/natural) heritage

Fig. 1. Observatory Halle an der Saale (photo: Gudrun Wolfschmidt)

It was not until the late 18th century that the university was able to construct its own buildings for scientific research. The chancellor of Halle University, Carl Christoph von Hoffmann (1735--1801), designated the Botanical Garden, which had belonged to the university since 1698, as the location for the observatory, as money for suitable land purchases was not available. An avenue of chestnut trees connected the observatory with the entrance to the botanical garden.

Through the mediation of Baron Karl Abraham von Zedlitz und Leipe (1731--1793), Carl Gotthard Langhans (1732--1808), the creator of the Brandenburg Gate in Berlin, was won as architect. Zedlitz was Prussian Minister for Academic Affairs and a friend of Hoffmann’s at the University of Halle.

Fig. 2a. Observatory Halle an der Saale (photo: Gudrun Wolfschmidt, 2021)

Fig. 2b. Observatory Halle an der Saale (photo: Gudrun Wolfschmidt, 2013)

The Halle Observatory was built in 1788 and has the shape of an octagonal tower (octagon with a lateral length of 3.2m, and a height of 12.5m), inspired by the Tower of the Winds (Aérides, Horologium des Andronikos, 1st century BC), near the Akropolis in Athens.
The Halle Observatory costed 5050 Thaler, for the instruments was included an amount of about 1800 Thaler. The octagonal tower is three storeys high and has four balconies on the top floor (these were added for observation, they do not exist on the Tower of the Winds). The balconies are strictly aligned with the cardinal points. The entrance is flanked by Tuscan columns.
On the ground floor is the vestibule for the attached Meridian Hall. The first floor housed a larger library, which was transferred to the Halle University and State Library in 1923. It is still kept there today as a special collection.
The refractor hall was located on the top floor. In 1826, the interior was remodelled; but the exterior Doric portal architecture, designed by Langhans, has been preserved.

Today, the observatory, located on the grounds of the Botanical Garden of the city of Halle (Saale), is considered the oldest building erected by the University of Halle and, along with the main university building (Löwengebäude), the most important example of classicist architecture in Halle -- long before Karl Friedrich Schinkel (1781--1841) became famous with neo-classic buildings, also with observatories like Berlin, New Observatory (1835) and Bonn Observatory (1844), as well as Christiana Observatory [today Oslo], 1833, designed by Christian Heinrich Grosch (1801--1865) and Schinkel.

Fig. 3a. Observatory Halle an der Saale (photo: Gudrun Wolfschmidt, 2021)

Fig. 3b. Observatory Halle an der Saale (photo: Gudrun Wolfschmidt, 2021)

History

Instruments

Heliograph, 1st half of 18th century, used for observing the Sun
Pendulum clock
Portable instrument (Portativ), made by Johann Christian Resener, 100 Thaler
5-foot-Transit instrument, made by Johann Christian Resener, 100 Thaler
Mural Quadrant, made by Royal Prussian Mechanician (Königlich preußischer Kammermechanikus) Johann Christian Resener of Berlin, 1000 Thaler --
the Mural Quadrant was given in the scrap metal collection during WWI
Achromatic telescope, made by Peter & John Dollond of London (1788)
Portable Quadrant after Jérôme Lalande (1732--1807), 1804, 500 Thaler
5-inch-Refractor
4 1/2-inch-Refractor
8 Theodolites
3 Sextants
Spectral apparatus, made by Schröder of Hamburg
Artificial Horizon

Fig. 4a. Georg Simon Klügel (1739--1812), director of Halle Observatory from 1788 to 1812, etching by Gottlob August Liebe (1746--1819), 1790 (Wikipedia)

Fig. 4b. Johann Friedrich Pfaff (1765--1825), director in Halle from 1812 to 1825 (Wikipedia)

Astronomers

Georg Simon Klügel (1739--1812) of Hamburg, studies in Göttingen, director in Halle from 1788 to 1812.
He published e.g.:
Dritter Theil. Die Astronomie mit der mathematischen Geographie, Schifffahrtskunde, Chronologie und Gnomonik, die physische Geographie, die praktische Mechanik und die bürgerliche Baukunst. Encyclopädie, oder zusammenhängender Vortrag der gemeinnützigsten, insbesondere aus der Betrachtung der Natur und des Menschen gesammelten Kenntnisse. Berlin (3rd ed.) 1782-1806.
Anfangsgruende der Arithmetik, Geometrie und Trigonometrie, nebst ihrer Anwendung auf praktische Rechnungen, das Feldmessen und die Markscheidekunst [Mine surveyor’s art]. Berlin: Nicolai 1798.
Johann Friedrich Pfaff (1765--1825) of Stuttgart, studied in Göttingen, professor in Helmstedt, director in Halle from 1812 to 1825
August Rosenberger (1800--1890) of Latvia-Courland, director in Halle from 1826 to 1832
Hugo Buchholz (1866--1921) of Lübeck, director in Halle from ~1895 to 1921
August Gutzmer (1860--1924), studied mathematics in Berlin, professor in Jena 1900 to 1905, in Halle from 1905 to 1924.

The estimate of costs for the restoration was 520,000 Mark (1922). This was the end of the observatory. The valuable observatory library was integrated in the University Library. The instruments were donated to the Physics Institute in 1923.
The building was used since 1923 by the Botanical Garden.

Fig. 4c. August Rosenberger (1800--1890), director in Halle from 1826 to 1832 (Wikipedia)

Fig. 4d. August Gutzmer (1860--1924), professor in Halle from 1905 to 1924 (Wikipedia)

State of preservation

Fig. 5a. Observatory Halle an der Saale (photo: Gudrun Wolfschmidt, 2021)

Fig. 5b. Observatory Halle an der Saale (photo: Gudrun Wolfschmidt, 2021)

The Halle Observatory (1788), the most important example of classicist architecture in Halle, is well preserved. The windows and the roof was restored in 2000. On the occasion of the 1200th anniversary of the founding of the city of Halle, the Martin Luther University Halle-Wittenberg presented to the city the restoration of the University Observatory in 2006. The Halle Observatory is now a listed building.

Comparison with related/similar sites

The Halle Observatory (1788) had an octagonal building, inspired by the Tower of the Winds in Athens, like e.g. Oxford Observatory, UK, or Observatory Leipzig (1861), and many others.

Threats or potential threats

no threats

Present use

In 1923, the observatory was dissolved. The headquarters of the floristic mapping of East Germany was located in this building.
Today the building houses social and work rooms for the Botanical Garden.

Astronomical relevance today

The Halle Observatory (1788--1923) is no longer used for astronomy.

In addition to this historical observatory in the Botanical Garden, the city of Halle has other observatories and planetariums. There is the Johannes Kepler Astronomical Station in Halle-Kanena.

Halle University opened a platform for astronomical observations at the Institute of Geography: In connection with offered events on astronomy and planetology, the platform on the roof of the Institute of Geography (von-Seckendorff-Platz 4) is used for star gazing. For observation two reflecting telescopes are currently available available.

Fig. 6. Space Flight Planetarium "Sigmund Jähn" (1978) with observatory in Halle (Saale), (Wikipedia, CC3, 3, Ralf Lotys, 2007)

The "Sigmund Jähn" space flight planetarium with observatory existed on Peißnitzinsel from 1978 to 2018. It had a spectacular architecture, designed by Klaus Dietrich with the architect and civil engineer Herbert Müller (1976/78). Müller used a special construction element he had developed, the HP shell. With this, he constructed the actual circular building from only five different types of shells, 28 of each. Müller was inspired by Ulrich Müther (1934--2007), who introduced the dynamically curved concrete shell structures.
Because of its location on Peißnitz Island, the planetarium was damaged several times by flooding of the Saale; the last flooging in 2013, damaged also the projector. It is a pity, that the city of Halle as owner decided to abandon the location. In addition, in 2014, Halle’s city council decided to demolish the planetarium building, the former space flight planetarium, which was since June 2015 a listed building.

Its successor building in a Gasometer on Holzplatz is scheduled to open in 2022.

References

Bibliography (books and published articles)

Acta über den Anbau des Observatorii zu Halle, 1788--1791. Special-Acten betreffend die Sternwarte, 1893--1916.
Universitätsarchiv Halle-Wittenberg.
Brülls, Holger & Dorothee Honekamp: Denkmalverzeichnis Sachsen-Anhalt. Bd.4. Stadt Halle. Halle: fliegenkopf 1996.
Brülls, Holger & Thomas Dietsch: Architekturführer Halle an der Saale. Berlin: Dietrich Reimer 2000.
Dolgner, Angela: Die Bauten von Carl Gotthard Langhans d.├ä. für die Universität Halle. In: Erbe und Gegenwart III. Materialien und Dokumente eines wissenschaftlichen Kolloquiums im Januar 1989. Hg. vom Kunstgeschichtlichen Institut; Kongress- und Tagungsberichte der Martin-Luther-Universität Halle-Wittenberg, wissenschaftliche Beiträge 1991/1, H. 13. Halle 1991, S. 37-44.
Heftrig, Ruth: Endlose Weiten auf der Peißnitz. Ein Nachruf auf das hallesche Raumflug-Planetarium "Sigmund Jähn". In: Sachsen-Anhalt-Journal (2021), Heft 4.
Kienast, Hermann: Der Turm der Winde in Athen. Wiesbaden 2014.
Knobloch, Eberhard: Klügel, Georg Simon. In: Neue Deutsche Biographie (NDB). Band 12. Berlin: Duncker & Humblot 1980, S. 135 f.
Kümmel, Fritz (Hg.): 300 Jahre Botanischer Garten der Martin-Luther-Universität Halle-Wittenberg. Halle: fliegenkopf 1998.
Speler, Ralf-Torsten & Stefan Lehmann: Die historische Sternwarte der Universität Halle und ihre Sammlung (1788--1923). In: Die akademischen Sammlungen und Museen der Martin-Luther-Universität Halle-Wittenberg. Hg. von Stephan Lehmann & M. Ruprecht. Halle (Saale) 2013, S. 86--87.
Stuart, James & Nicholas Revett: The Antiquities of Athens (1750). London: Haberkorn 1762--1830.
Wolfschmidt, Gudrun: Cultural Heritage and Architecture of Baroque Observatories. In: From Alexandria to Al-Iskandariya -- Astronomy and Culture in the Ancient Mediterranean and Beyond. European Society for Astronomy in Culture -- Société Européenne pour l’astronomie dans la culture (SEAC), Proceedings of the 17th Annual SEAC Meeting 2009 in Alexandria, Egypt. Ed. by Michael Rappenglück & Mosalam Shaltout. Gilching, Germany (SEAC Publication) 2021, p. 147-154 (Octagonal observatory buildings).