Johan Maurits Mohr (ca. 18 August 1716, Eppingen – 25 October 1775, Batavia) was a Dutch-German pastor who studied at Groningen University from 1733 and settled in Batavia (Dutch East Indies) in 1737. Mohr's greatest passion was in astronomy but he was also keenly interested in meteorology and in vulcanology. In 1765 Mohr built a large private observatory in Batavia that was equipped with the best astronomical instruments of his time. His observatory, which had cost him a small fortune, was visited and praised by Louis Antoine de Bougainville and James Cook. Mohr observed the Venus transits of 6 June 1761 and 3 June 1769 and the Mercury transit of 10 November 1769. He also made meteorological observations and measurements of the magnetic declination at Batavia. After Mohr's death, his observatory was damaged by an earthquake in 1780, fell into ruin and was demolished in 1812. The minor planet 5494 Johanmohr is named in his honour. References H.J. Zuidervaart & R.H. van Gent, " "A Bare Outpost of Learned European Culture on the Edge of the Jungles of Java": Johan Maurits Mohr (1716-1775) and the Emergence of Instrumental and Institutional Science in Dutch Colonial Indonesia", Isis: An International Review devoted to the History of Science and its Cultural Influences, 95 (2004), 1-33. See also List of colonial buildings and structures in Jakarta 1716 births 1775 deaths 18th-century Dutch astronomers Dutch Protestant ministers and clergy Colonial architecture in Jakarta People from Heilbronn (district) University of Groningen alumni Dutch East India Company people