FOOTNOTES:
[192] This mode of verifying configurations, though something of the boldest, was by no means unusual. On a former occasion Kepler, wishing to cast the nativity of his friend Zehentmaier, and being unable to procure more accurate information than that he was born about three o'clock in the afternoon of the 21st of October, 1751, supplied the deficiency by a record of fevers and accidents at known periods of his life, from which he deduced a more exact horoscope.
[193] Kepler probably meant his own mother, whose horoscope he in many places declared to be nearly the same as his own.
[194] See Preliminary Treatise, p. 13.
[195] In allusion to the Harmonics of Ptolemy.
[196] This is a word borrowed from the Ptolemaic astronomy, according to which the sun and planets are hurried from their places by the daily motion of the primum mobile, and by their own peculiar motion seek to regain or be restored to their former places.
[197] In other parts of his works, Kepler assumes the diminution to be proportional to the circles themselves, not to the diameters.
[198] In many curves, as in the circle and ellipse, there is a point to which the name of centre is given, on account of peculiar properties belonging to it: but the term "centripetal force" always refers to the place towards which the force is directed, whether or not situated in the centre of the curve.