As his instruments were not sufficiently protected from solar radiation, and as he placed them inside the basket, his temperature measurements were particularly high and affected by errors. In the following years, most scientific balloon flights were made by French scientists such as Camille Flammarion, Gaston Tissandier and Wilfrid de Fonvielle. However, the investigation of the upper atmosphere remained isolated endeavors of individual researchers until the 1890s. 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. The temperature profiles made by Glaisher had long stood as secure knowledge, although there had been isolated doubts about their validity, as they conflicted with theoretical predictions. Aßmann and Sigsfeld saw now the possibility to critically test Glaisher's results with their new instrument. On 2 June 1888, Wilhelm von Bezold made a speech at the 100th meeting of the German Society for the Promotion of Aviation on "The Meaning of Aviation to Meteorology". In this speech, he sketched a program of cooperation between meteorology and aviation in the investigation of the upper atmosphere, that was well received by members of the Society. Its implementation dominated the activities of the Society for more than a decade. Already on 23 June 1888, Sigsfeld's balloon "Herder" made its first trip. Significant capital was required to undertake this endeavor. Through donations from Society members (Rudolph Hertzog, Werner von Siemens, Otto Lilienthal), the tethered balloon "Meteor" was purchased. The Royal Prussian Academy of Sciences made a one-time grant of 2000 Marks.