Page - 134 - in Maximilian Hell (1720–92) - And the Ends of Jesuit Science in Enlightenment Europe

© PER PIPPIN ASPAAS AND LÁSZLÓ KONTLER, ����  |  doi:10.1163/9789004416833_005 This is an open access chapter distributed under the terms of the CC-BY-NC-ND 4.0 License. Chapter 3 A New Node of Science in Action: The 1761 Transit of Venus and Hell’s Transition to Fame I reckon there is no one interested in astronomy who does not wait impa- tiently to learn what was observed during the recent meeting of Venus with the Sun, especially since there is no other encounter between celes- tial bodies from which we are able to ascertain with a greater degree of exactness the still unknown, or not yet sufficiently well defined, paral- laxes of the Sun and Venus. Eustachio Zanotti 17611 1 A Golden Opportunity The above assessment of Hell’s Bolognese colleague Eustachio Zanotti could hardly have been more to the point. The passage (or transit) of Venus in front of the Sun as seen from the Earth is a rare astronomical phenomenon: it comes in pairs separated by eight years, after which it does not take place for more than a whole century. The first transit of Venus observed by means of astro- nomical equipment was in 1639. Since then, transits of Venus have occurred in the years 1761 and 1769, 1874 and 1882, and 2004 and 2012—but they will not happen again until 2117 and 2125. The 1639 transit of Venus made no immediate impact and (as far is known) was only observed by two amateur astronomers in the English countryside.2 By contrast, the pre-calculated transits of 1761 and 1 Eustachio Zanotti, De Veneris ac Solis Congressu Observatio habita in Astronomico Specula Bononiensis Scientiarum Instituti Die 5 Junii mdcclxi (Bologna: Laelii e Vulpe, 1761), 1. 2 The observers were Jeremiah Horrocks (c.1618–41), observing from outside Liverpool, and his friend Simon Crabtree (1610–40), observing from the Manchester area. See Peter Aughton, The Transit of Venus: The Brief, Brilliant Life of Jeremiah Horrocks, Father of British Astronomy (London: Windrush, 2004); Allan Chapman, “Jeremiah Horrocks, William Crabtree, and the Lancashire Observations of the transit of Venus of 1639,” in Proceedings of the International Astronomical Union, Volume 2004, June 2004: Transits of Venus; New Views on the Solar System and Galaxy, Proceedings iau Colloquium, ed. Don W. Kurtz, no. 196 (Cambridge: Cambridge University Press, 2004), 3–26; Thomas Posch and Franz Kerschbaum, “Kepler, Horrocks, He- velius und der Venustransit von 1631,” in Astronomy in and around Prague. Colloquium of the Working Group of the History of Astronomy, Prague, September 20, 2004, ed. Gudrun Wolf- schmidt and Martin Šolc (Prague: Univerzita Karlova, 2005), 89–100.