Collection of Kepler's Works. 389 



kept the conviction of the importance of such an undertaking 

 alive, and a further investigation of the great work increased 

 the interest for the old astronomer and philosopher. The 

 present editor, however, Prof. Frisch, did not long enjoy the 

 assistance of either Pfafi^ or of the great philologist, Prof. 

 Kopp, both being carried off by premature death. The 

 labour was subsequently much aided by the head librarians of 

 Stutgardt and Tubingen, who defrayed the preparatory ex- 

 penses of the undertaking. Of especial use also was the li- 

 brary of Reiitlingen, which contains a very complete collec- 

 tion of the mathematical works of the sixteenth century. All 

 this must of necessity have led to the inquiry after the original 

 MSS. of Kepler, a notice of which is to be found in Murr's 

 Journal fur Kunstgeschichte und allgemeine Literatur, vols. iii. 

 and xvii. It is to the following effect : — Kepler's son Ludwig, 

 who died in 1663, had preserved the MSS. of his father with 

 the intention of publishing a selection from them. In fact, there 

 appeared in 1634, through his endeavours, a work which, how- 

 ever, the father had prepared for the press, viz. S omnium sive 

 de Astronomid lunari. All the rest remained unused, most pro- 

 bably because Ludwig, who was a physician, could not under- 

 stand the problem of his great progenitor. From him the 

 MSS. went to the celebrated Selenographer Hevel, and thence 

 to his son-in-law, the common-councilman Lange at Dantzig. 

 Of Lange they were bought in 1707 by the Leipzig mathe- 

 matician, Hansch, for 100 florins. They consisted of twenty- 

 two folio volumes, which, besides the drafts of several works 

 already printed (for instance, the Har?nonie, the Rudolphine 

 Tables, &c), contained the correspondence of Kepler with 

 many distinguished personages, several astronomical works 

 merely begun, and a host of miscellaneous notices. Hansch 

 intended to publish these MSS. in a splendid form, but was 

 only able to begin this undertaking (too costly in the form he 

 had projected it), and the Epistolce ad Keplerum scripta?, in- 

 sertis ad easdem responsionibus Keplerianis, which was patron- 

 ized by the emperor Charles VI., was the only result he ever 

 achieved. The MSS. thus published, are to be found in the 

 Imperial Library of Vienna. As Hansch fell into poverty, 

 he was obliged to pledge the MSS.; and as he could not 

 redeem them, one Etringer, of Frankfort on the Maine, re- 

 deemed them for 128 florins. Thence they came (probably 

 by inheritance) to a Mrs. Trummer at Frankfort, where they 

 remained unknown until 1770, when Christopher de Murr, a 

 man deserving well of literature, called attention to them. 

 For the purpose of recovering them from oblivion, he ad- 

 dressed himself to several astronomers, as Mayer, Bernouilli, 



