Seite - 286 - in Maximilian Hell (1720–92) - And the Ends of Jesuit Science in Enlightenment Europe

Chapter 6286 Monsieur Pingré was really annoyed because of the letter you wrote to him. He complained to me, as if I was behind it. However, it is first and foremost he himself who is to blame for criticizing in an indecent man- ner the observations of Yours, which are more valuable than his own.86 As we have seen, during the 1760s Hell gradually became more self-confident and disputed not only Pingré’s parallax but also some other works by French astronomers. However, before 1770 he seems not to have been engaged in any disputes with “the most important French astronomer of the eighteenth century.”87 For all its fragmentary status, the epistolary evidence to hand sug- gests that Hell and Lalande remained close allies during the 1760s. That changed with Lalande’s reaction to the Vardø report. Around the year 1761, Hell and Lalande were both “shooting stars” on the international stage. Lalande waited impatiently behind the back of Delisle to become the main nodal astronomer of the time. Hell, no less ambitious, could not dream of similar laurels but was working strenuously toward securing Vi- enna a firm place on the same stage. By 1769, he succeeded, while by that time Lalande—in his own eye, certainly—emerged as the worldwide coordinator of the entire Venus transit enterprise. The first seed of discontent was probably sown when neither Hell nor Denmark–Norway asked for his advice in the plan- ning of the Vardø expedition. But their independent behavior went beyond that. The datasets from Vardø were not shared with Lalande immediately: he had to wait in line behind the Danish king, along with every astronomer except the few Copenhagen-based savants who attended oral presentations at the ses- sions of the Danish Society of Sciences in November and December 1769. A third element that annoyed Lalande was the peculiar method in calculating the coordinates of Vardø, especially the pole height method described above. The fourth issue at stake was of course the conclusions drawn concerning the solar parallax itself. Unlike the previous occasion, Lalande and Hell disagreed fundamentally here. Instead of standing on the side-lines, the two stepped for- ward to become the main characters in a heated scientific controversy. When calculating the solar parallax, contemporary astronomers could choose between two strategies. One option was to wait for all observations to be published and then undertake a thorough survey of all the available data. Ideally, such a survey would lead to a decisive conclusion, “the author’s final word” on the matter. Another modus operandi was to make repeated cal- culations as the various datasets emerged. Tentative adjustments following 86 Lalande to Hell in Vienna, dated Paris, December 29, 1763, in Pinzger, Hell Miksa, 2:191. 87 Jean-Claude Pecker, “Préface,” in Dumont, Un astronome des Lumières, 1–7, here 3.