LIFE AND WORKS OF KEPLER. 105 



home You blame my manner of accusing and refuting'. I 



yield the point, though I do not think that I have deserved your re- 

 proaches. From you, my friend, there is no reproof which I do not 

 accept. I regret that you did not come to Prague; I would have 

 explained my theories, and you would have returned, I trust, fully satis- 

 fied. Yon jeer me. So be it; let us laugh together. But why accuse 

 me of comparing the works of Tycho with the muck-heaps of Augeas"? 

 You had not my letters under your eye ; you would have seen that they 

 contained nothing of the kind. The name of Augeas has found a lodg- 

 ment only in your own imagination. I do not dishonor my astronomical 

 labors by scurrilities." And in concluding: "Adieu," he says; " write 

 to me as soon as possible, to the end that I may know that my letter 

 has changed your feelings in regard to me." 



The i)eace with the lieirs of Tycho, was but a brief truce; they 

 addressed themselves to the Emperor himself; but Rudolidi, though 

 incapable as Emperor and King, had an enlightened and sincere love 

 for the sciences, and put aside all these importunate cavilings. Sur- 

 rounded, however, with enemies and rebels, the Emperor of Germany 

 could scarce pay his astronomer some light installments on the con- 

 siderable amount which he had fixed as his salary, and Kepler, in order 

 to support his family, was compelled to accept labor of every sort, to 

 make almanacs, calculate horoscoi)es, and place his erudition at the 

 service of every one who could pay for it. 



After the death of Kudolph, his successor, Matthias, less fovorable 

 to science and not less embarrassed by the incurable divisions which 

 distracted the empire, entirely abandoned the observatory of Prague, 

 so that its labors were interrupted through the failure of the most in- 

 dispensable supplies. Kepler was constrained to relin(piish employ- 

 ments which no longer yielded him even bread, and to accept the func- 

 tions of professor at the University of Linz. It was in this city that 

 he lost his wife, Barbara. Not long afterward, in order, he said, to give 

 a mother to his three children, but without affecting to have made by 

 doing so any great sacrifice on their account, he married again. After 

 having compared with much care and subtlety of discrimination, as we 

 see in one of his letters, the merits and attractions of eleven young i)er- 

 sons commen<led to him by his friends, he espoused Susannah Kent- 

 linger, orphan daughter of a simple artisan, who had been carefully 

 educated in one of the most distinguished boarding-scliools of the 

 country. " Her beauty, her habits, her form,'' he writes, " everything 

 about her suits me. Patient and industrious, she will know how to 

 conduct a modest household, and, though not in her first youth, she is 

 of an age to learn all that may be wanting." This marriage was the 

 occasion of an important work, in which Kepler shows by a new example 

 that his genius, in its comprehensive survey, embraced all the depart- 

 ments of science. "As I was about to be married," he says in the pre- 

 face, " and the vintage was abundant and wine cheap, it was incumbent 

 on a good father of a family to make provision thereof and replenish 

 his cellar. Having therefore bought several casks, the vintner, a few 

 days after, made his appearance with a view to ascertain the price by 

 measuring their capacity, and, without making any calculation, plunged 

 an iron rod into each cask and at once pronounced its contents." Kep- 

 ler then recalls that on the banks of the liliine, doubtless because wine 

 is there more costly, the trouble is taken of emi)tying the barrel in order 

 to count exactly the number of quarts it contains. Is the much uiore 

 expeditious method practiced in Austria sufticieutly exact ? "This is 

 a question," says Kepier, "the study of which is not unworthy of a 



