Page - 290 - in Maximilian Hell (1720–92) - And the Ends of Jesuit Science in Enlightenment Europe

Chapter 6290 it must have been “adulterated.”98 This prejudice must have brought Lalande to neglect the fact that Planman had been stationed at a site (Cajaneborg) where the Sun was extremely low above the horizon, causing the limbs of the sun to undulate strongly, whereas Hell in Vardø had enjoyed perfect atmospheric conditions and the Sun elevated more than 6.5 and 10° above the sea during ingress and egress respectively. Hell meant he could prove Planman to have either defined the longitude of his site erroneously by at least thirty-five sec- onds, or observed the exterior contact of egress wrongly by thirty-five sec- onds.99 Lalande, on the other hand, who considered Hell’s report worthy of rejection, had made various sophisticated calculations in order to make the Cajaneborg observation as complete as he needed it. The interior contact of egress— unobserved by Planman because of clouds—was found by Lalande by altering the diameter of both Venus and the Sun by a number of seconds. In this way, he managed to fit Planman’s observations to the data obtained in Ta- hiti and California, thereby defending his result of 8.50″ for the mean horizon- tal parallax of the Sun.100 Repeatedly, Hell dismisses his Paris antagonist as “the protector and defender of the incomplete and erroneous Cajaneborg ob- servation” and as a friend of his personal ambition rather than the truth.101 But if Planman’s observation really had been as exact as Lalande wanted it to be, each and every colleague of his must have been mistaken by between twenty- four and forty-eight seconds in time.102 This absurdity would no doubt lead neutral colleagues to agree that the parallax value of Hell, rather than that of Lalande, was correct. In sum, Hell concluded that “Tahiti and Vardø will be the two columns upon which the true solar parallax of 8.70″ will rest firmly and be preserved—like upon pillars of bronze—to the eternal memory of posterity, a memory which coming generations will decorate again and again with their palms of victory.”103 For, “we are now living in a time […] when England, Ger- many, Italy, Denmark, Sweden, and Russia all excel in their own astronomers, who know very well how to decide for themselves what difference there is be- tween truth and wrong.”104 One of the “neutral” and able calculators alluded to by Hell was the young Lexell in St. Petersburg. Lexell published various attempts between the au- tumn of 1770 and the end of 1772, arriving at parallaxes of 8.80″, 8.76″, and 98 Hell, “De parallaxi Solis,” 86–93. 99 Hell, “De parallaxi Solis,” 8–39. 100 Hell, “De parallaxi Solis,” 103–5. 101 Hell, “De parallaxi Solis,” 8, 38, 86, 94, 110–15. 102 Hell, “De parallaxi Solis,” 100–1. 103 Hell, “De parallaxi Solis,” 109. 104 Hell, “De parallaxi Solis,” 114–15.