FORMAL ASTRONOMY. 533 



Tiv his case the persecution went mainlv on the broad ground of his be- 

 ing a Protestant, and extended to great numbers of persons at that 

 time. The circumstances of this and other portions of Kepler's life have 

 been brought to light only recently through an examination of public 

 documents in the Archives of WUrtemberg and unpublished letters of 

 Kepler. (Johann Keppler's Leben und "Wirken, nach neuerlich autuv- 

 fundenen Manuscripten bearbeitet von J. L. C. Freiherrn v. Bivit- 

 schwart, K. Wurtemberg. Staats-Rath. Stuttgart, 1831.) 



Schiller, in his History of the Thirty Years' War, says that when 

 Ferdinand of Austria succeeded to the Archduchy of Stiria, and found 

 a great number of Protestants among his subjects, he suppressed their 

 public worship without cruelty and almost without noise. But it ap- 

 pears now that the Protestants were treated with great severity. Kep- 

 ler held a professorship in. Stiria, and had married, in 1597, Barbara 

 Muller, who had landed property in that province. On the llth of 

 June, 1598, he writes to his friend Maestlin that the arrival of the 

 Prince out of Italy is looked forwards to with terror. In December 

 he writes that the Protestants had irritated the Catholics by attacks 

 from the pulpit and by caricatures ; that hereupon the Prince, at the 

 prayer of the Estates, had declared the Letter of License granted by 

 his father to be forfeited, and had ordered all the Evangelical Teachers 

 to leave the country on pain of death. They went to the frontiers of 

 Hungary and Croatia : but after a month, Kepler was allowed to re- 

 turn, on condition of keeping quiet. His discoveries appear to have 

 operated in his favor. But the next year he found his situation in 

 Stiria intolerable, and longed to return to his native country of Wur- 

 temberg, and to find some position there. This he did not obtain. lie 

 wrote a circular letter to his Brother Protestants, to give them conso- 

 lation and courage ; and this was held to be a violation of the conditions 

 on which his residence was tolerated. Fortunately, at this time he was 

 invited to join Tycho Brahe, who had also been driven from his native 

 country, and was living at Prague. The two astronomers worked to- 

 gether under the patronage of the Emperor Rudolph II. ; and when 

 Tycho died in 1G01, Kepler became the Imperial Mathematicus. 



We are not to imagine that even among Protestants, astronomical 

 notions were out of the sphere of religious considerations. When Kep- 

 ler was established in Stiria, his first official business was the calcula- 

 tion oFthe Calendar for the Evangelical Community. They protested 

 against the new Calendar, as manifestly calculated for the furtherance 

 of an impious papistry: and, say they, "We hold the Pope for a hor- 



