314 COSMOS. 



The figurative and poetical mytlis of the Pythagorean and 

 Platonic pictures oi the universe, changeable as the fancy from 

 which they emanated,* may still he traced partially reflected 

 in Kepler ; but while they warmed and cheered his often sad- 

 dened spirit, they never turned him aside from his earnest 

 course, the goal of which he reached in the memorable night 

 of the loth of May, 1618, twelve years before his death. 1 

 Copernicus had furnished a satisfactory explanation of the ap- 



astronomical coutemplation of the structure of the universe, from the 

 earhest ages to Newton's system of gravitation. 



* Plato, in the Phcedrus, adopts the system of Philolaiis, but in the 

 Timcsits, that according to which the earth is immovable in the center^ 

 and which was subsequently Called the Hipparchian or the Ptolemaic 

 (Bockh, De Platonico systemate ccelestium globoriim, el de vera indole as 

 tronomicB Philolaicce, p. xxvi.-xxxii. ; the same author in the Philolaos, 

 s. 104-108. Compare, also, Fries, Geschichie der Philosophie, bd. i., s 

 325-347, with Martin's Etudes sur Timie, t. ii., p. 64-92.) The astro 

 nomical vision, in which the structure of the universe is shrouded, at 

 the end of the Book of the Republic, reminds us at once of the intercal 

 ated spherical systems of the planets, and of the concord of tones, " the 

 voices of the Syrens moving in concert with the revolving spheres." 

 (See, on the discovery of the true system of the universe, the fine and 

 comprehensive work of Apelt, Epochen der Gesch. der Menscheit, bd. i., 

 1845, s. 205-305, and 379-445.) 



t Kepler, Harmonices Mundi, libri quinque, 1619, p. 189. "On the 

 8th of Alarch, 1618, it occun'ed to Kepler, after many unsuccessful at 

 tempts, to compare the squares of the times of revolution of the planets 

 with the cubes of the mean distances ; but he made an error in his cal- 

 culations, and rejected this idea. On the 15th cf May, 1618, he again 

 reverted to it, and calculated correctly. The third law of Kepler was 

 now discovered." This discovery, and those related to it, coincide 

 with the unhappy period when this great man, who had been exposes 

 from early child-hood to the hardest blows of fate, was striving to save 

 from the "torture and the stake his mother, who, at the age of seventy 

 years, in a trial for witchcraft, which lasted six years, had been accus- 

 ed of poison-mixing, inability of shedding tears, and of sorcery. The 

 suspicion was increased from the circumstance that her own son, the 

 wicked Christopher Kepler, a worker in tin, was her accuser, and that 

 she had been brought up by an aunt, who was burned at ^Veil as a 

 witch. See an exceedingly interesting woi'k, but little known in for- 

 eign countries, drawn from newly-discovered manuscripts by Baron von 

 Breitschwert, entitled " Johann Keppler^s Leben und Wirken," 1831, s. 

 12, 97-147, and 196. According to this w^ork, Kepler, who in German 

 letters always signed his name Keppler, was not born on the 21st of 

 December, 1571, in the imperial town of Weil, as is usually supposed, 

 but on the 27th of December, 1571, in the village of Magstadt, in WOr- 

 temberg. It is uncertain whether Copernicus was born on the 19th of 

 January, 1472, or on the I9lh of February, 1473, as Mostlin asserts, ot 

 (according to Czynski) on the 12th of February of the same year. Tho 

 year of Columbus's birth was long undetermined within rin-etr>er y^a'-g. 

 Ramusio places it in 14-^0. Bemaldez, the friend of the discoverer, in 

 1436, and the celebrated historian Mnnoz in 1446. 



