But... Kepler’s problem was to be resolved, to find the position of a body moved in an elliptical orbit at a given time. As concerns an algebraic res… - David Gregory

[T]he increases of optics, geography and other sciences... are also due to the application of the more intricate geometry to philosophical matters. Hence has been made clear the curvature of the rays of light in the same medium; hence the causes of extraordinary s have been laid bare; hence, given one surface of a lens, another may be determined by means of which a ray entering the lens with given position will have a given position in emerging from it; hence in geography the excess of the normal diameters of the axis over the axis is found, and also the al figure of any planet; hence the varying gravity of the same body in different parts of the Earth, and the varying length of an isochronous pendulum according to the latitude of its place, and then indeed, after the due correction, the construction of a universal measure and of a perfect .

That saying is well known, so often used by Anaxagoras, and his Scholars, Achelaus and Euripides, Namely, "That the Sun and Stars were fiery or red-hot Stones and Golden Clods." Of the same mind also were Democritus, Metrodorus, and Diogenes...

[T]he motion of comets is found to be not at all dissimilar to the motion of the planets, depending on the same principles and undergoing continual revolutions. But, since these planets move in ellipses in which the distance of the foci has a great ratio to the transverse axis, and that major axis is immense, their periodic times greatly exceed the periodic times of the common planets, for they are in the sesquialteral ratio [3:2] of the transverse axes [their squares are as the cubes of the axes]. Thus Descartes’s rectilinear cometary trajectory, which he filched from Kepler, collapses, and many things about comets in his fable of the world may be added, which almost two thousand years ago had been shown to be impossible by Lucretius. Such is the free motion in full spaces, to say nothing of the fact that in his system the motion is from time to time against the motion of the vortex. But, in place of so eccentric ellipses whose more remote parts cannot be observed because the comet is not visible there, parabolae may be assumed in calculation, and many things useful for improving astronomy and physics and advancing them further may thus be deduced with the help of the more intricate geometry.