CONTENTS. xvii 



Page 



Some difficulties of the Cartesian theory which are considered 



by Newton - .... 301 



a. The Sun s rotation. LII., Cor. 4. - - 30.3 



/3. The third law of Kepler. Scholium LIU. - ib. 



y. The two first laws of Kepler, Scholium LIU. - ib. 



8. The density of the planets, LIU. -.- - ib.- 

 t. The disturbance of the sun s motion by the planetary 



vortices, LII., Cor. 5. &c. - 304 



CHAPTER X. 



THEORY OF COMETS. 



1. The comets are planets moving in very eccentric conic 



sections - _ . 30 (j 



2. To determine the particular orbit of a given comet - 207 



APPENDIX. 



Note I. Galileo s persecution, 417. 



Note II. Another demonstration to p. 58., 420. 



Note III. Force varying inversely as the distance, 421. 



Note IV. Central forces to more than one point, 424. 



Note V. Leibnitz s Dynamical tracts, 437. 



