Chapter XV - Correction of the Motions according to Rudolphi

Summary

Since the error which I discovered in the Rudolphian tables is so great, it may not be amiss to shew how the calculation may be amended in order to agree with this and other observations. I quite agree in the form of Kepler's hypotheses, and gladly receive both his annual and diurnal motion of the earth. I am of opinion also that these motions do not arise from complicated fictions of useless circles, but from natural and magnetic causes, and that they are owing to the rotation of the Sun on its axis. He knows but little of astronomy who is ignorant that the figure of the orbit is elliptical; that its centre is the body of the Sun, and not a fictitious point near it: that the motion of the planet is really unequal; that the whole apparent inequality does not proceed from its eccentricity alone; and finally, that the inclination of all the orbits to the ecliptic is not influenced by the annual motion, but is fixed and constant. No one, we repeat, who denies such facts is sufficiently acquainted with astronomical observations.