Zusammenfassung
Summary
The optical telegraph line Berlin-Koblenz was operational from 1833 to 1849. The telegraph No. 4 in Potsdam was dismantled without any remains more than 150 years ago. Direction observations of Johann Jacob Baeyer in the frame of the Prussian triangulation survey 1838 to 1846, where also telegraphs have been observed, are used to reconstruct the position. For this purpose, a subnetwork of 11 stations has been readjusted. The obtained location is only about 10 m away from the replica of the telegraph established in 2009 next to the building A31, today »Potsdam-Institut für Klimafolgenforschung«.