Berlin Observatory
The construction of the new Berlin Observatory proceeded from a cabinet order of 10 November 1830 according to the design of Schinkel. An approximately one hectare plot was acquired at a price of 15,000 Thalers in the present-day area of Berlin-Kreuzberg. The foundation stone was laid on 22 October 1832 and the observatory was ready by 1835, on the area currently bounded by the streets ″Friedrichstraße″, ″Besselstraße″ and ″Lindenstraße″. The southern end of the ″Charlottenstraße″ was later named ″Enckeplatz″ in honor of the director at that time and the observatory acquired the address of Enckeplatz 3 A (now: ″Enckestraße 11″).
Berlin Observatory
In September 1699, the Reichstag decided to introduce an "improved calendar" to the Protestant German states without having to take on the Gregorian Calendar, introduced by Pope Gregory XIII in 1582. The 'improved calendar' was introduced the following year and resulted in 18 February 1700 being followed by 1 March. A patent for the calendar was granted to the planned Berlin Observatory by Prince-elector Frederick III on 10 May 1700 and eight days later Gottfried Kirch was appointed to Director of the Observatory. On 11 July (his 43rd birthday) the Kurfürst signed a document formally founding an Academy and an Observatory in Berlin. Therefore, Berlin received an academy just like those already existing in London, Paris and Rome - the Prussian Academy of Sciences (originally German name: ″Kurfürstlich-Brandenburgische Societät der Wissenschaften″), based on the plans of Gottfried Wilhelm Leibniz. Leibniz became the first president of the Academy. The fees resulting from the calendar patent were the almost single financial basis of the institution for a long period. The society originally had no actual observatory of its own and Kirch carried out his observations at various private observatories including, from 1705, the private observatory of Geheimrat Bernhard Friedrich von Krosigk on the Wallstrasse, in Cölln. Kirch was assisted by his wife Maria Margarethe and his son Christfried. Maria Margarethe discovered, among other things, the comet of 1702. In the meantime the Kurfürst had been raised in 1701 to the rank of King in Prussia. On 1 January 1710, the capital was expanded by uniting the previously independent towns of Dorotheenstadt, Friedrichstadt, Friedrichwerder, and Cölln and Berlin (the oldest ones).