vi CONTENTS. 



SECT. 8. 



Eclipses of the Moon, 138 



Eclipses of the Sun, 145 



Number of Eclipses, 152 



9. Planets, 155 



Orbits of the Planets, 170 



Rotation of the Planets, 178 



10. Secondary Planets, 180 



Ring of Saturn, 189 



11. Comets, 193 



12. Aberration of Light, and the Nutation of the 



Earth's Axis, 200 



- 13. Dimensions of the Solar System, 209 



14. The Annual Parallax, and distance of the Fixed 



Stars, 214 



APPENDIX. 



On the method of determining by observation 



i-j ..=.the- constant co-efficients in an assumed or 



-given function of a variable quantity, ...... 219 



?'-'. .,..,...., . . OsO -N . 



nia ii. 



u8 . 



PHYSICAL ASTRONOMY. 



;rIT 



SECT. 1. Forces which retain the Planets in their Orbits, 229 



2. Forces which disturb the Elliptical Motions of 



' : the Planets, 245 



Disturbance in the Moon's motions, ....247 



3. Disturbance in the Motions of the Primary Pla- 

 nets, from their action on one another, 265 



SECT. 





