Berlin Observatory
The Berlin Observatory (Berliner Sternwarte) is a German astronomical institution with a series of observatories and related organizations in and around the city of Berlin in Germany, starting from the 18th century. It has its origins in 1700 when Gottfried Leibniz initiated the "Brandenburg Society of Science″ ("Sozietät der Wissenschaften") which would later (1744) become the Prussian Academy of Sciences ("Preußische Akademie der Wissenschaften"). The Society had no observatory but nevertheless an astronomer, Gottfried Kirch, who observed from a private observatory in Berlin. A first small observatory was furnished in 1711, financing itself by calendrical computations.
Berlin scientific balloon flights
In 1885, Wilhelm von Bezold was appointed to the newly established Chair for Meteorology at the Friedrich-Wilhelms-Universität, and as the director of the Prussian Meteorological Institute, both in Berlin. He profoundly restructured the institute, and hired three scientific commissioners on 1 April 1886, among whom was the physician and meteorologist Richard Aßmann from Magdeburg. Aßmann had been working since 1883 on a measurement device that could measure the air temperature accurately in spite of the disruptive effect of solar radiation. In 1887, Aßmann joined the Society for Promotion of Aeronautics (founded in 1881) together with other early Berlin meteorologists, where he got to know the engineer Hans Bartsch von Sigsfeld. Sigsfeld had worked on the same problem for the aviation department (established in 1884) of the Railway Troops of the Prussian Army. Together, they developed the Aßmann aspiration psychrometer, which excluded the influence of sunlight through shielding and permanent ventilation.