Tycho Brahe · 1926
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For twenty-one years on the island of Hven, and afterwards in Bohemia, Tycho Brahe and his assistants recorded what they saw. This volume completes the Thesaurus Observationum, the record gathered from the surviving logbooks by J. L. E. Dreyer for his edition of Tycho’s complete works.
Observation from 1596 through 1601, the year of Tycho’s death. The record follows him from Hven into exile: among it are the observations made at Wandsbek, near Hamburg, and the observations of seven comets. Each year is set out as the logbooks kept it, with the Sun, Moon and planets in turn.
The published books of Tycho Brahe give his conclusions. The logbooks give the evidence: the data from which Kepler derived the elliptical orbit of Mars, and still the most accurate body of naked-eye positional astronomy ever assembled. The manuscripts themselves have never been digitized, so Dreyer’s edition is one of only two complete and reliable witnesses to them.
The source is the 1926 Copenhagen volume of Dreyer’s Tychonis Brahe Dani Opera Omnia, from the TIB Hannover. The record begins in Thesaurus Observationum, Tomus Primus.