![Liesganig](https://upload.wikimedia.org/wikipedia/commons/0/0e/Liesganig.jpg)
Joseph Xaver Liesganig (13 February 1719 – 4 March 1799) was a Jesuit priest and geodesist who was a professor of mathematics at the
University of Vienna
The University of Vienna (german: Universität Wien) is a public research university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world. With its long and rich histor ...
. He taught mathematics from 1742 at the
University of Graz
The University of Graz (german: link=no, Karl-Franzens-Universität Graz, ), located in Graz, Austria, is the largest and oldest university in Styria, as well as the second-largest and second-oldest university in Austria.
History
The unive ...
. He was involved in measuring the extent of Austria, establishing the longitude of Vienna and in early trigonometrical mapping of the region. He was the last of the Jesuit astronomers at the Vienna observatory.
Life and work
Liesganig was born to Wolfgang, Hofmeister of Graz, and Rosalie. He went to study at the Jesuit College in Vienna from 1734 and was ordained in the
Society of Jesus
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, image_size = 175px
, caption = ChristogramOfficial seal of the Jesuits
, abbreviation = SJ
, nickname = Jesuits
, formation =
, founders ...
in 1749. He taught mathematics from 1742 at the
University of Graz
The University of Graz (german: link=no, Karl-Franzens-Universität Graz, ), located in Graz, Austria, is the largest and oldest university in Styria, as well as the second-largest and second-oldest university in Austria.
History
The unive ...
. In 1751 he received a doctorate from the Academy in Kosice and joined an expedition into the Tatra mountains. The next year, he became a professor the next year at the University of Vienna, while also serving at the astronomical observatory of the Jesuit College at Vienna. He succeeded
Maximilian Hell
Maximilian Hell ( hu, Hell Miksa) (born Rudolf Maximilian Höll; May 15, 1720 – April 14, 1792) was an astronomer and an ordained Jesuit priest from the Kingdom of Hungary.
Biography
Born as Rudolf Maximilian Höll in Selmecbánya, Hont Co ...
in 1756 as director of the observatory. Liesganig took a keen interest on question of the exact shape of the earth, which was of great interest in the period. In 1757, on the instance of
Ruđer Bošković
Roger Joseph Boscovich ( hr, Ruđer Josip Bošković; ; it, Ruggiero Giuseppe Boscovich; la, Rogerius (Iosephus) Boscovicius; sr, Руђер Јосип Бошковић; 18 May 1711 – 13 February 1787) was a physicist, astronomer, ...
, he had a zenith sector of 10 (Viennese) foot radius as well as a quadrant with two-and-half foot radius constructed by the mechanic Joseph Ramspoeck. He obtained a
Graham
Graham and Graeme may refer to:
People
* Graham (given name), an English-language given name
* Graham (surname), an English-language surname
* Graeme (surname), an English-language surname
* Graham (musician) (born 1979), Burmese singer
* Clan ...
clock with a gridiron compensation pendulum. With this equipment in place, in 1758, he established the longitude of Vienna as 48°12′34.5″. After this he was involved in 1762 in measuring a base line near Neustadt (6238
toises long, 12158 metres) and another in Marchfield (6388 toises). An arc of about 3° was measured near Vienna. He used a star reference for some of his trigonometrical work, however he made an error because not all stations used the same star as a reference, leading to errors. In 1769 he proposed the measurement of another meridian arc in Hungary, writing to Empress
Maria Theresa
Maria Theresa Walburga Amalia Christina (german: Maria Theresia; 13 May 1717 – 29 November 1780) was ruler of the Habsburg dominions from 1740 until her death in 1780, and the only woman to hold the position ''suo jure'' (in her own right). ...
for her support. An arc of 2° was measured between Kistelek and Csurog and he triangulated in the area to produce one of the early accurate maps of the region. Other collaborators included Karl Scherflers (1716-1783), Georg Ignaz Metzburg (1735-1798) His Vienna triangulation was re-examined in 1806 and it was found to be in error only by about 7mm per kilometre. His book ''Dimensio Graduum Meridiani Viennensis et Hungarici'' (1770) described his cartographic work. In 1772, parts of the Russian Empire went into Austria and Liesganig was ordered to map the new territory of
Galicia and
Lodomeria
Lodomeria is the Latinized name of Volodymyr (Old Slavic: , ; uk, Лодомерія, ; pl, Lodomeria; sk, Lodomeria; hu, Lodomeria; cz, Vladiměř; ; ro, Lodomeria), a Ruthenian principality also referred to as the Principality of Volhyni ...
(Volyhnia). He was assisted by
Franz Xavier von Zach (1754–1832) and he moved his instruments from Vienna to the observatory at
Lviv
Lviv ( uk, Львів) is the largest city in western Ukraine, and the seventh-largest in Ukraine, with a population of . It serves as the administrative centre of Lviv Oblast and Lviv Raion, and is one of the main cultural centres of Ukraine ...
where he then worked until his death.
File:Liesganig quadrant.jpg, Liesganig's quadrant
File:Zenith telescope.jpg, Zenith telescope
Map Liesganig3.jpg, Triangulations
File:Map Liesganig2.jpg, Map fragment
File:Galizien_und_Lodomerien_Liesganig_Map_1824_copy.jpg, Map based on Liesganig's work
Map_Liesganig1.jpg, Map fragment
File:Galizien_und_Lodomerien.jpg, 1780 map of Galizia and Lodomeria based on Liesganig's survey
References
External links
Dimensio graduum meridiani Viennensis et Hungarici(1770)
{{DEFAULTSORT:Liesganig, Joseph Xaver
1719 births
1799 deaths
Austrian astronomers