CHAPTER XVI.

The sun's neighbours still exercise their attraction over him 282 Regions of greatest density in the 9 nebulæ dealt with; compared with the orbits of the planets made from them 283 Results of comparison favourable to the theory 287 Differences of size in the planets have arisen from variations in the quantity of matter accumulating on the nebulæ 289 Causes of the retrograde motions in Neptune, Uranus, and their satellites 290 Probable causes of the anomalous position of Neptune 292 Rises and falls in the densities and dimensions of the planets explained 293 The form of the nebulæ must have resembled a dumb-bell 295 More about rises and falls in densities 296 Reason why the Asteroid nebula was the least dense of the system 297 Not necessary to revise the dimensions given to the 9 nebulæ 298 Causes of the anomalies in the dimensions, densities, etc., of the Earth and Venus 299 The strictly spherical form of the sun accounted for. But it may yet be varied 299 Repetition that a spherical body could not be made from a lens-shaped nebula by attraction and condensation 300