CHAPTER X.

OBSERVATIONAL ASTRONOMY IN THE EIGHTEENTH CENTURY, §§ 196-227 247-286

§ 196. _Gravitational astronomy_: its development due almost entirely to Continental astronomers: use of _analysis_: English observational astronomy 247

§§ 197-8. _Flamsteed_: foundation of the Greenwich Observatory: his star catalogue 249

§ 199. =Halley=: catalogue of Southern stars 253

§ 200. Halley’s comet 253

§ 201. _Secular acceleration of the moon’s mean motion_ 254

§ 202. Transits of Venus 254

§ 203. _Proper motions_ of the fixed stars 255

§§ 204-5. Lunar and planetary tables: career at Greenwich: minor work 255

§ 206. =Bradley=: career 257

§§ 207-11. Discovery and explanation of _aberration_: the _constant of aberration_ 258

§ 212. Failure to detect parallax 265

§§ 213-5. Discovery of _nutation_: _Machin_ 265

§§ 216-7. Tables of Jupiter’s satellites by Bradley and by _Wargentin_: determination of longitudes, and other work 269

§ 218. His observations: _reduction_ 271

§ 219. The density of the earth: _Maskelyne_: the _Cavendish experiment_ 273

§ 220. The _Cassini-Maraldi_ school in France 275

§ 221. Measurements of the earth: the Lapland and Peruvian arcs: _Maupertuis_ 275

§§ 222-4. _Lacaille_: his career: expedition to the Cape: star catalogues, and other work 279

§§ 225-6. _Tobias Mayer_: his observations: lunar tables: the longitude prize 282

§ 227. The transits of Venus in 1761 and 1769: distance of the sun 284