Contents xxiii 



PAGE 



239. Advance made by Lagrange and Laplace on the 



work of their immediate predecessors . . 308 



240. Explanation of the moon's secular acceleration by 



Laplace 308 



241. Laplace's lunar theory: tables of Burg and Burck- 



hardt 309 



242. Periodic and secular inequalities . . . .310 



243. Explanation of the mutual perturbation of Jupiter 



and Saturn : long inequalities . . . .312 



> 244-5. Theorems on the stability of the solar system : 



the eccentricity fund and the inclination fund . 313 



246. Tne magnitudes of some of the secular inequalities 318 



247. Periodical inequalities: solar and planetary tables 



based on the Me'canique Celeste . . . .3*8 



248. Minor problems of gravitational astronomy : the 

 satellites : Saturn's ring : precession and nuta- 

 tion : figure of the earth : tides : comets : masses 

 of planets and satellites ..... 318 



249. The solution of Newton's problem by the astro- 

 nomers of the eighteenth century . . . 319 



250. The nebular hypothesis : its speculative character . 320 



CHAPTER XII. 

 HERSCHEL (FROM 1738 A.D. TO 1822 A.D.), 251-271 . 323-353 



251-2. William Herschel's early career: Bath: his 



first telescope 323 



253-4. The discovery of the planet Uranus, and its 



consequences : Herschel's removal to Slough . 325 



255. Telescope-making : marriage : the forty-foot tele- 

 scope : discoveries of satellites of Saturn and of 

 Uranus 327 



256. Life and work at Slough : last years : Caroline 



Herschel 328 



257. Herschel's astronomical programme : the study of 



the fixed stars 330 



258. The distribution of the stars in space : star- 

 gauging : the " grindstone " theory of the 

 universe : defects of the fundamental assump- 

 tion : its partial withdrawal. Employment of 



