BOOK II. On the Law of Universal Gravitation, and on the Motion of the Centres of Gravity of the Heavenly Bodies.-Chap. 1, On the Law of Universal Gravitation, collected from Phenomena; chap. 2, On the Differential Equations of the Motion of a System of Bodies acting on each other by their mutual Attraction ; chap. 3, First Approximation to the Celestial Motions, or Theory of tho Elliptic Motion; chap. 4, Determination of the Elements of the Elliptic Motion ; chap. 5, General Methods for determining the Motions of the Heavenly Bodies by successive Approximation; chap. 6, Second Approximation to the Celestial Motions, or Theory of their Perturba tions; chap. 7, On the Secular Inequalities of the Celestial Motions ; chap. 8, Second method of Approximation to the Celestial Motions (by the Variation of Elements).
In vol. ii. are contained BooK III. On the Figure of the Celestial Bodies."--Chap. 1, On the Attraction of Homogeneous Spheroids, terminated by surfaces of the second order ; chap. 2, Development of the Attraction of all Spheroids
in Series ; chap. 3, On the Figure of Equilibrium of a Homogeneous Fluid Maas which has a Rotatory Motion • chap. 4, On the Figure of a Spheroid which differs little from a Sphere, and is covered by a stratum of fluid in equilibria; chap. 5, Comparison of the preceding theory with observation; • chap. 6, On the Figure of Saturn's Ring; chap. 7, On the Figure of the Atmospheres of the Heavenly Bodies.
Boots IV. On the Oscillations of the Sea and the Atmosphere. Chap. 1, Theory of the Ebb and Flow of the Sea ; chap. 2, On the Stability of the Equilibrium of the Sea ; chap. 3, On the method of taking into account, in the Theory of the Tides, the various circum stances peculiar to each port ; chap. 4, Comparison of the preceding theory with observation.