CONTENTS Introduction Ancient Conceptions Concerning the Motions of the Sun, Moon, Planets and Stars The Geometry of Planetary Motions from Copernicus to Kepler The Discovery of the Law of Gravitation The Attraction of Material Bodies of Different Shapes Experimental Detection of Attraction between Material Bodies on Earth Newton's Law---The Theoretical Basis of Celestial Motion Celestial Motion and the Two-Body Problem The Concept of Perturbed Motion. Celestial Mechanics and Practical Astronomy Ways of Describing Perturbed Motion. The Variational Orbit The Problem of Motion in the Solar...