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 telescope:
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 assumption: its partial withdrawal. Employment of
brightness as a test of nearness: measurement of brightness:
“space-penetrating” power of a telescope 332

§ 259. _Nebulae_ and _star clusters_: Herschel’s great catalogues 336

§ 260. Relation of nebulae to star clusters: the “island
universe” theory of nebulae: the “shining fluid”
theory: distribution of nebulae 337

§ 261. Condensation of nebulae into clusters and stars 339

§ 262. The irresolvability of the Milky Way 340

§ 263. _Double stars_: their proposed employment for finding
parallax: catalogues: probable connection
between members of a pair 341

§ 264. Discoveries of the revolution of double stars:
_binary stars_: their uselessness for parallax 343

§ 265. The motion of the sun in space: the various
positions suggested for the _apex_ 344

§ 266. Variable stars: _Mira_ and _Algol_: catalogues of
comparative brightness: method of _sequences_:
variability of α _Herculis_ 346

§ 267. Herschel’s work on the solar system: new satellites:
observations of Saturn, Jupiter, Venus, and Mars 348

§ 268. Observations of the sun: _Wilson_: theory of the
structure of the sun 350

§ 269. Suggested variability of the sun 351

§ 270. Other researches 352

§ 271. Comparison of Herschel with his contemporaries:
_Schroeter_ 352