had lived since 1612) when the letter arrived in Würtemberg, and it had no effect. After publishing the Tabulæ Rudolphinæ in 1627, he thought the following year, while living at Sagan, in Silesia, under Wallenstein's patronage, of getting the observations printed. He wrote on the 17th August 1628 to Jörgen Brahe that he hoped soon to commence the printing, but as he had found a selection from the observations of the years 1600 and 1601 inserted in Snellius' edition of the Landgrave's observations,[1] he inquired if Brahe still had the originals for those two years, or whether Snellius could have got hold of them, so that his widow might have them still.[2] Nothing came, however, of the intended edition, and the original observations remained in Kepler's possession, and after his death in that of his son, the physician, Ludwig Kepler.[3]
But while Kepler retained the originals as pledges for the considerable arrears of salary due to him, a set of unfinished copies in quarto volumes had remained in Austria.[4] These volumes are alluded to by Tycho Brahe in his Mechanica (fol. G. 2), where he mentions that the observations had been entered in large volumes, and afterwards, for each year, copied into separate volumes and sorted according to subject—the sun, moon, planets (beginning with Saturn and ending with Mercury), and the fixed stars. Albert Curtz, a Jesuit, and Rector of the College of Dillingen, on the Danube, who had corresponded with Kepler both on scientific and religious subjects, conceived the idea of publishing Tycho's observa-
- ↑ "Coeli et siderum in eo errantium observationes Hassiacæ . . . et specilegium biennale ex observationibus Bohemicis V. N. Tychonis Brahe." Lugd. Batav., 1618, 4to. Snellius had as a youth of twenty paid a short visit to Prague in 1599 or 1600. See R. Wolf's Astr. Mitth., lxxii.
- ↑ Breve og Aktstykker, p. 152. About Kepler's intention of publishing the observations, see his Opera, vi. pp. 616, 621, vii. p. 215 (in his book T. Brahei Hyperaspistes, Frankfurt, 1625, against Scipione Chiaramonte, who in his book Antitycho had tried to prove from Tycho's own works that comets are sublunary), also viii. p. 910. Gassendi, p. 207.
- ↑ On the outside of the cover of the volume for 1596–97 (bound in old music-paper) there is pasted a slip of paper on which Kepler has written: "Extract aus mein Johan Kepplers den Brahischen Erben zugestelter Erklerungsschrift. Entlich und zum fünften sol auf einem jedem Tomum herabgemeldeten Observationen, sobalt ich nach Linz komme ein offene Zettel auffgeleimet, und meinen Erben, darinnen von mir anbefohlen werden, dass solche Bücher, da ich etwa Todtes verbliche, absobalden zu meinem Schatz oder Kleinodien eingesperret und vor der Eröffnung Jhr. Kay. May. so wie auch denen Brahischen Erben, umb weitere Vorsorg und Verwahrung deroselben angemeldet werden, damit also die Erben auch auff diesem Fall, de abgesetzten ersten Puncts halben desto mehr versichert sein."
- ↑ Or perhaps they were purchased from Kepler's daughter, if the MS. account printed by Kästner is authentic (Geschichte d. Math., ii. p. 651 et seq.).
