Die Keplerbriefe auf der Nationalbibliothek und auf der Sternwarte in Paris

Walther von Dyck·1927

The Latin texts of Kepler’s letters to Johann Seussius and Philipp Müller (1622–1630) found in Paris by Walther von Dyck, with letters of Kepler’s son-in-law Jacob Bartsch and the Danzig astronomer Peter Crüger on the Rudolphine Tables, the Ephemerides, Kepler’s death and the fate of his papers, from Nova Kepleriana 4 (1927).

Contents

1. Vorbemerkung pp. 3–4

   Von Dyck explains how he found these letters of Kepler, Bartsch and Crüger in Paris at Easter 1914, why the edition was delayed by the war, and that Max Caspar shared the translation and notes; he calls for a complete edition of Kepler's correspondence.

2. Einleitung pp. 5–12

   The history of Philipp Müller's correspondence, bought by Joseph-Nicolas Delisle in 1736, partly stolen from the Paris Observatory by Guglielmo Libri and bought back from the Ashburnham library in 1888, with a list of every letter in it and of which survive.

3. Kepler to Seussius, 15 July 1622 pp. 27–29

   Kepler thanks Seussius for Philipp Müller's theses against the astrologer Paul Nagel, recalls his own pseudonymous attack on the end-of-the-world prophets and his quarrel with Robert Fludd, and comments on Müller's theses on the cross in Cygnus, the new star and Johann Arndt.

4. Kepler's Postscript on Bartolus, September 1622 pp. 30–33

   Kepler asks the astrologer Abraham Bartolus, through Müller, on what grounds he takes harmonic intervals as effective aspects, and sets out his own method: aspects arise from the division of the circle by inscribed figures, and the harmonies of the monochord only derive from them.

5. Kepler to Müller, 17/27 October 1629 pp. 65–67

   Amid the ruin of the war, Kepler sends two journeymen to Leipzig to buy a press, have type cast and paper made for printing Tycho Brahe's observations, and asks Müller to advance money from his and Bartsch's funds; with a note on the Danish astronomy of Longomontanus.

6. Kepler to Müller, 13/23 November 1629 pp. 67–70

   Kepler thanks Müller for arranging his type and paper, and pours out his distress over a rival suitor, a secretary of the Margrave of Baden, who is pressing for his daughter Susanna's hand while her betrothed Jacob Bartsch is away.

7. Kepler to Müller, 4 January 1630 pp. 70–71

   Kepler hopes the type and paper are ready at Leipzig and arranges carriage to Sagan, reports what he has heard of Bartsch at Strasbourg, and settles the accounts, resolved to go on printing whatever happens.

8. Kepler to Müller, 16/26 January 1630 pp. 72–73

   Kepler reports the arrival of paper from Prague, asks Müller to stop any further Leipzig paper beyond what is ordered, and says the printing of Terrentius's letter from China and of the first pages of the Ephemerides has begun.

9. Kepler to Müller, 27 February 1630 pp. 73–74

   Kepler sends copies of the letter from China and asks for Müller's judgement, ethical as well as astronomical, with a bitter remark on the portents the war has brought Germany.

10. Kepler to Müller, 22 April 1630 pp. 74–76

    Back from Wallenstein at Gitschin, Kepler sends 600 copies of the Ephemerides for 1630–1633, comments on the type and the signs cast for them, and asks Müller to urge Bartsch and Susanna to hurry to Sagan for the christening of his newborn daughter.

11. Kepler to Müller, 26 August 1630 pp. 76–77

    Kepler sends the remaining years of the Ephemerides, to 1636, in two casks, with instructions for storing them at Frankfurt and for the entry in the fair catalogue.

12. Kepler to Müller, 2 September 1630 pp. 78–79

    Kepler sends Friedrich Bartsch to see to the sale of the Ephemerides and defends giving Wallenstein his title as Duke of Mecklenburg in the dedication. His last letter to Müller; he died at Regensburg two months later.

13. Bartsch's Open Letter to Kepler, 1628 pp. 92–95

    Bartsch dedicates the first ephemeris computed from the Rudolphine Tables to the University of Strasbourg, and in an open letter tells Kepler how he came to compute it with the new logarithmic method, and of his plans for 'practical spheres' that would show the planetary motions to the eye.

14. Bartsch to Müller, 30 April 1629 pp. 97

    Bartsch tells Müller he has agreed to compute ten years of ephemerides for Kepler, to be published at Frankfurt by Tampach, and that he and his brother work at the calculation night and day.

15. Bartsch to Müller, 29 July/8 August 1629 pp. 97

    Bartsch sends Kepler's Sportula and announces that he will pass through Leipzig on his way to Frankfurt and Strasbourg.

16. Bartsch to Müller, 9/19 January 1630 pp. 97–98

    From Strasbourg, Bartsch reports that Kepler's daughter Susanna is now living in Bernegger's house awaiting the wedding, that he has been promised a chair of mathematics, and that he will take his medical doctorate and marry at the end of February.

17. Bartsch to Müller, 7/17 November 1630 pp. 98

    With Kepler away at Regensburg, Bartsch plans small astronomical tables to make the Rudolphine Tables easier to use, wishing his father-in-law a safe return; Kepler had died two days before.

18. Bartsch to Müller, 3 January 1631 pp. 99–100

    Bartsch laments Kepler's death at Regensburg, 'the sun of all astronomers', and tells of a fruitless fortnight at Gitschin trying to get Wallenstein to pay Kepler's salary and keep the press going.

19. Bartsch to Müller, 5 May 1631 pp. 101–102

    Driven from Sagan by the war, Bartsch writes from Lauban about settling Kepler's estate, sends the Somnium and his own tables, discusses prices for the Rudolphine Tables and Ephemerides, and reports that he now has Tycho Brahe's observations.

20. Müller to Bartsch, 8 May 1631 pp. 103–104

    Müller replies to Bartsch about the copies he has received and their prices, advises printing the second volume of the Ephemerides at home, sends a gift for Kepler's grandson, and quotes Crüger's excuse for writing no poem on Kepler's death.

21. Bartsch to Müller, 19/29 June 1631 pp. 104–105

    Bartsch, forced 'from the stars to the rakes', writes of Kepler's widow and children now at Lauban, his logarithmic tables, the price of the Ephemerides, and the poems on Kepler's death.

22. Bartsch to Müller, 3 September 1631 pp. 105

    Setting out with Kepler's widow for Prague, Regensburg, Linz and Vienna, Bartsch leaves instructions for selling the tables, Ephemerides and Somnium.

23. Crüger to Müller, Easter Monday 1620 pp. 106–107

    Crüger rejects Kepler's theory of straight-line comet paths because it assumes the earth's annual motion, mocks the 'rabid leaps' it implies, and finds the Astronomia nova and Harmonice mundi hard to follow.

24. Crüger to Müller, 1 July 1622 pp. 107–108

    Crüger finds Kepler's physical astronomy pleasing but obscure, accuses him of bending Tycho's observations to fit his harmonies and Copernicanism, and turns hopefully to Longomontanus's newly published Astronomia Danica.

25. Crüger to Müller, 9 August 1622 pp. 107

    Having read the fourth book of Kepler's Epitome more than once, Crüger still cannot understand its proportions of the planetary orbs and bodies, and suspects Kepler of obscuring things on purpose.

26. Crüger to Müller, August 1623 pp. 108

    Crüger thanks Müller for Kepler's latest writings, which, as an Italian said, are as marvellous as the man, and which carry him out of himself whenever he reads them.

27. Crüger to Müller, 4/14 April 1624 pp. 108

    Crüger admires Kepler's acumen but will not subscribe to his hypotheses for Mars, hoping God will show another way to the true theory.

28. Crüger to Müller, Palm Sunday 1628 pp. 108

    Having seen the Rudolphine Tables announced in the Frankfurt catalogue, Crüger orders a copy and confesses a great longing for them.

29. Crüger to Müller, 4/14 December 1629 pp. 109–110

    Having worked through the Rudolphine Tables, Crüger tells Müller that further work on the Astronomia Danica is now pointless, praises the tables' methods and logarithms, and is no longer averse to elliptical orbits.

30. Crüger to Müller, Easter Monday 1631 pp. 110

    Crüger mourns Kepler, regretting the unfinished works he had promised, and declines to write a funeral poem.

31. Crüger to Müller, 12/22 April 1634 pp. 111

    Crüger asks where the papers of Kepler and Bartsch and Tycho's observations now are, and wishes they were somewhere safe from the wars.

32. Crüger to Müller, 20/30 September 1634 pp. 111

    Crüger cannot afford to buy the posthumous papers of Kepler and Bartsch from their widows himself, and the Danzig council is taken up with the Swedish truce.

33. Crüger to Müller, 31 December 1634 pp. 111

    Commissioned by the Danzig council, Crüger asks Müller for a catalogue of Kepler's papers for sale, and whether Tycho's observations are the widow's to sell.

34. Crüger to Müller, Easter Tuesday 1635 pp. 111–112

    Crüger reports a visit from Kepler's son Ludwig: the widow and children are stranded at Frankfurt, Kepler's papers are kept at Sagan, and the Emperor's debt might be used to win Tycho's observations for an edition at Danzig.