received observations from his former pupils, Longomontanus, who at that time was staying at Rostock, and Christen Hansen of Ribe, who observed it in Jutland, and who had formerly observed the comet of 1593 at Zerbst. It appears that Tycho got some kind of information about this eclipse from somebody at Hveen, perhaps from David Petri (Pedersen), whom he had left in charge of the buildings and other property on the island, as Tycho afterwards wrote both to Magini and Kepler that the eclipse had been observed at Hveen from beginning to end (while only the beginning was seen at Wandsbeck owing to clouds), and that the time of beginning and end agreed well with his own tables.[1] With the exception of this eclipse of the sun and two of the moon, and a few meridian altitudes of the sun, the planets only were observed at Wandsbeck. Tycho felt that the thousand star-places were enough to have to show to the world, and he felt that observations of the planets were of greater value to complete the material accumulated at Hveen. He was assisted at Wandsbeck by Johannes Müller, mathematician to the Elector of Brandenburg, who had visited him at Hveen in 1596, and whom he was requested by the Electress to train not only in chemistry but also in the
- ↑ In the letter to Magini (28th November 1598, Carteggio, p. 222, also p. 238), Tycho says that the middle of the eclipse at Uraniborg was observed at 11h. 5m. a.m., magn. of eclipse between 9 and 10 digits. In the letter to Kepler he wrote (Dec. 9, 1599, Opera, i. 225) that the observer at Hveen found by the large armillæ the beginning, end, and middle, in accordance with Tycho's tables. In his Optics Kepler made use of this observation, and gave the contacts as having occurred at 10.3 and 12.32 (Opera, ii. 367), but in the Tab. Rudolph., p. 110, he says that Origanus had observed 1013 and 12.32, and that the figures given in the Optics must have been copied from Origanus, putting 10.3 for 1013 (compare Opera, ii. 441). But if so, this is no fault of Tycho's, as he did not give any observed contacts. There is nothing about this observation in the Historia Cœlestis, nor could I find it in the original volume for 1596–97. Tycho does not mention the name of the observer at Hveen, only in the letter to Kepler he says the observation was made "a quodam istic relicto studioso."
