[126] "For it is not necessary that these hypotheses be true, nor even probable, but this alone is sufficient, if they show reasoning fitting the observations."

[127] Kepler: Apologia Tychonis contra Ursum in Op. Om.: I, 244-246.

[128] Prowe: II, 251, note.

[129] Ibid: II, 537-9.

[130] Ibid: II, 273.

[131] Ibid: II, 286-7.

[132] A second copy was found at Upsala shortly afterwards, though for centuries its existence was unknown save for two slight references to such a book, one by Gemma Frisius, the other by Tycho Brahe. Prowe: II, 284.

[133] Ibid: II, 273-4.

[134] Prowe: II, 274, note.

[135] Prowe: II, 426-440.