In 1763, the physicist and philosopher Christian Mayer was appointed court astronomer by Elector Carl Theodor after he had set up an observatory on the roof of Schwetzingen Palace in 1761 with a movable dome and equipped inside with a Lepaute clock and a Canivet quadrant. This Schwetzingen observatory was also the zero point of the approximately 12 km long "Basis Palatina", a section of the axis running to the Königstuhl in Heidelberg. This formed the baseline for surveying the Electoral Palatinate, an area of 360 square kilometres. Christian Mayer drew up the "Charta Palatina" from 1764-72 as the first attempt of this kind in Germany. Even today, the survey is attested to be astonishingly accurate.
