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″).
Discovery of Neptune
The telescope, at New Berlin Observatory (1835–1913), that discovered Neptune was an achromatic refractor with an aperture of 9 Paris inches (9.6 English inches, or 24.4 cm). Made by the late Joseph Fraunhofer's firm, Merz und Mahler, it was a high-performance telescope of its era, with one of the largest achromatic doublets available and a finely made equatorial mount, with a clock drive to move the 4 m (13.4′) main tube at the same rate as Earth's rotation. Eventually the telescope was moved to the Deutsches Museum in Munich, Germany, where it can still be seen as an exhibit.