Page - 146 - in Maximilian Hell (1720–92) - And the Ends of Jesuit Science in Enlightenment Europe

Chapter 3146 observations of global significance was no longer questionable. At the helm of it all, incidentally, was the Jesuit Maximilian Hell. Not all observers reported directly to the astronomical giants of Paris and London. Some shared their data with Hell, leaving it to him to assess and publish their observations. The report included in the Ephemerides for the year 1762 was not the only instrument of promoting Hell’s (and Vienna’s) reputation. As already men- tioned, around the time of the 1761 transit of Venus, the scholarly community in Vienna received prominent visitors from Paris: following Chappe d’Aute- roche’s  visit en route to Siberia in January, the director of the Observatoire Royal, Cassini de Thury, arrived in mid-May. Principally on a geodetic mission sponsored by the two new diplomatic and military allies, France and the Habsburg monarchy, Cassini de Thury stayed long enough to observe the tran- sit of Venus in the early morning hours of June 6 from Liesganig’s observatory. Cassini de Thury already held Hell in high esteem, and the reason for his choice of location is probably as simple as given in his own account of his trip: the Jesuit observatory was “preferable to that of Father Hell because of its situation and because of the abundance of instruments.”23 While it was Hell who bore the title “imperial and royal,” the dynasty chose to follow Cassini de Thury in honoring the Jesuit observatory with the presence of one of its members. As Cassini de Thury reports: As I was waiting for the reappearance of the Sun impatiently, […] the august archduke Joseph [arrived], who left Laxenburg at four o’clock in the morning in order to witness my observations; luckily, the Sun re- vealed itself again, and this prince looked at Venus several times, and posed me several questions that testified to the range of his knowledge.24 that were delivered to Hell are still preserved among his manuscripts at the Univer- sitätssternwarte Wien. 23 César-François Cassini de Thury, Relation de deux voyages faits en Allemagne par ordre du Roi: Par rapport à la figure de la Terre […] Par rapport à la geographie […] Par rapport à l’astronomie […] (Paris: Durand, 1763), xiv. Cassini de Thury’s appreciation for Hell as a colleague who has “given great proofs of his competence and exactitude in the practice of astronomical observations” is expressed on viii. On the location, cf. also Cassini de Thury, “Observation du passage de Vénus sur le Soleil, faite à Vienne en Autriche,” Histoire de l’Académie Royale des Sciences 1761 (published 1763): 409; Hell, “Observatio transitus Ven- eris […] 1761,” 17–20, 41. The claim that Cassini de Thury observed the transit “from the comfortable quarters of the Vienna Observatory” in the company of “the observatory’s director, Father Maximilian Hell” (Maor, Venus in Transit, 87, repeated in Wolfgang Stei- nicke and Wilhelm Brüggenthies, “Maximilian Hell und der Venustransit von 1769: Eine abenteuerliche Reise nach Vardø,” VdS-Journal 15 [2004]: 78–81, here 78) is mistaken. 24 Cassini de Thury, “Observation,” 410.