APPENDIX.
TYCHO BRAHE'S FAMILY, AND THE FATE OF HIS SCIENTIFIC COLLECTIONS.
It was perhaps well for Tycho Brahe that his career in Bohemia was cut short, for he would sooner or later have been bitterly disappointed in the faith he had placed in the Emperor's promises. His greatest wish had always been that the observatory work should not cease at his death, but that some competent person might be appointed to carry it on; but though Kepler, two days after Tycho's death, was informed by Barwitz that he was to be the new Imperial mathematician, the observations with Tycho's instru- ments were not continued very long. The Emperor soon agreed with Tycho's family to purchase the instruments for the sum of 20,000 thaler; but when Tengnagel came back to Prague in the summer of 1602, he assumed the position of Tycho's scientific heir, promised the Emperor to have the Rudolphine tables finished within four years, and though Kepler had commenced to observe Mars, he was deprived of the instruments, which were stored away in a vault under Curtius' house. Kepler never got access to them again, of which he complains repeatedly in his writings.[1] They seem to have been preserved in this manner until the year 1619, when the Bohemians rose against the House of Habsburg and elected Frederic V., Elector Palatine, their king, and during the disturbances which followed, some of the rebels are said to have destroyed the instruments as Imperial
- ↑ Opera, ii. p. 760 (in the dedication to Hoffmann of the book on the star in Cygnus), and p. 755. In the book on the star in Serpentarius (ibid., ii. 656) Kepler quotes a few observations by Tengnagel, "in viridario Cæsaris, ubi deposita habebantur instrumenta Braheana." Perhaps they had then (October 1604) been brought back to Ferdinand I.'s villa. In December 1601 and May 1603 Kepler used one of Tycho's clocks in observing two lunar eclipses (Opera, ii. P. 300).
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