Kepler left behind him many volumes of MSS. Heve lius purchased these from his representatives, and has given a list of them in the .P.hilosophical Transactions for 1674, No. 102, with the following remarks : " As to the MSS. of the celebrated Kepler, 1 purchased them all from his representatives for a certain sum, as well of those that have been published, as those that have never yet been pub lished ; among which are a great many letters that passed between him and other celebrated persons. Among these MSS. are found several well deserving to be published, not only many letters, but some works also ; among which is his Hipparchus, which, though not quite digested, might be easily put in sufficient order for that purpose. I have also his MSS. Chronology ; but I do not find a written ac count of his life, though there are numerous facts and traits, from which a clear account of it might be given." These AISS. were, after the death of Hevelius, purchased from his heirs by M. Gottlieb llausch, a zealous mathemati cian.
With a view of giving them to the work!, Hansel' was presented to the emperor Charles VI. and obtained from him a thousand to dert ay the expense, and a pension of 300 florins during- the ltle of the emp; rot'. With this pecuniary aid, he published at In 'psic, in 1718. in one vo ldro, Elastolte ad Joannem Keplerum, Mathematicum Casarei4711. IPSO eiS ad rasdcm Keple riaois. quotquot hactenus reperiri poturrunt. opus 7:ovum, coin Jo. Kt/aril vita ; jussu et auspiciis Caroli VI. Ro nan Imp. Ilaving.spebt all the 1000 ducats on tnis volume, and being obliged even to pledge the rest of the MSS. for S28 florins. Hanseh was unable to publish the rest of the MSS. Ile addressed himself to the celebrated Wolfius to no purpose. and was equally unsuccessful in his application to the Royal Society of London, and to other quarters. At
this time. M. de Murr of Nuremberg, happening to be in London in 1761 made great efforts to acquire the MSS. and Dr. Bradley had almost determined to purchase them. In 1773, 4000 francs were asked for them ; and some time af terwards, :al. de Murr succeeded in purchasing them for the Imperial Academy of St. Petersburg. The following are the contents of the 22 volumes of MSS. four of which Were published by Hanst h.
1. Hipparchus Kepleri, 279 leaves.
2. K. 'nevi Anversavia tabidarum lunarium, &c. cum Caktatarin in aivnum 1605,152 leaves.
3. De stt.l a n Na Kepleri annotata et observationes, alio rumque epistoice.
4. Commentaria in Piolimmi Harmonicorum librum ter tium. At istoxeni, musici antiqui, Harmonicorum elemen torum libri ties.
5. De gcnesi magnitudinum.
6, 7, 8. The letters which have been published and de posited in the imperial library.
9. Epistolx Kepleri, partly in Latin and partly in Ger man, with many calculations.
10. Epistolx Davidis Fabricii ad Keplerum cum respon sionibus 1601, 1609.
II. Litteraa.
12. Letters which have been published.
13. Demonstrationes motuum Mercurii et Veneris. • 14. Commentaria lefii407ce in theOriain Martis.
15. Documenta observatarum et examinatarum eclipsium.
16. Chronologia reformata Kepleri.
17. Not2e in Scaligeri et Petavii Doctrinam temporum.
18. Kepleri astronomica genethliaca et gcnealogica varia.
19. Discursus de anno lunari.
20. Kepleri SChedx authenticx Tabularum Rudolphi narum.
21. In 4to. Canon rectanguli spherici inehoatus. Me diorum motuum lunx correctio et constitutio Tabula rum Rudolphinarum emendationes. Tabula proportiona lis, sed canon hexacontaton sive sexagenortn.
22. In 4to. De quadrantibus libellus, along with other de tached pieces.
For a very full and able account of the discoveries of Kepler, sec Dr. Small's .1ccount of the 4stronomical Dis coveries of Kepler. Lond. 1804 8vo.