Mannheim Observatory

The Mannheim Observatory was a tower observatory built between 1772 and 1774 in Mannheim, Germany, which remained in operation until 1880. The observatory was transferred to Karlsruhe and finally in 1898, was established on the Königstuhl near Heidelberg where today’s successor institution the State Observatory Heidelberg-Königstuhl is located.

The observatory tower is now owned by the city and was restored in 1905-1906, and after the Second World War. Since 1958, the tower houses studio flats.

The Palatinate Elector Karl Theodor was a prince of the Age of Enlightenment. The French thinker Voltaire was a frequent visitor to his Court, the Elector made numerous reforms during his reign and founded scientific institutions. The Physics Institute, established in 1751 in Heidelberg, had as its Professor of Experimental Physics and Mathematics the Jesuit Father Christian Mayer.

In 1756 Mayer was sent to Paris to study the local water supply, he also studied at one of the centres of contemporary astronomy. He was given an Astronomical Quadrant, by the instrument maker, Canivet. In 1759, he observed the return of the comet predicted by Edmond Halley.

Mayer observed the Transit of Venus across the Sun on 6 June 1761 from a temporary Observatory built of wood by Karl Theodor in the Orangery in the park of Schwetzingen Castle. The observations convinced the elector as early as July to begin work on an observatory building on the palace roof, which was inaugurated in 1764.

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