Pickering, W. H., origin of Phœbe, 97, 238; photograph of a great nebula, 212; satellite discoveries, 237, 240 Plato, conception of a world-soul, 8 Poincaré, rotational equilibrium, 101, 105, 110, 143; destiny of the solar system, 243-4 Prestwich, Laurentian graphite, 279 Proctor, structure of the Milky Way, 214 Protoplasm, its properties, 270-273 Protyle, supposed discovery, 149, 154-7; function and qualities, 152; cosmic relations, 164-5 Prout, unity of matter, 152 Radio-activity, possible effects, 33-4, 229; discovery, 157; nature and cause, 158-9, 162-3, 196 Red stars, affinities, 224-6 Redi, transmission of life, 268 Reynolds, explanation of gravity, 170; molecular physics, 188, 192-3 Richter, germ-laden aerolites, 280 Roberts, A. W., systems of R2 Centauri and of V Puppis, 111, 113 Roberts, Isaac, spiral arrangements of stars, 214 Roche, planet-making expedients, 48; reconstruction of Laplace's hypothesis, 62-67 Roche's limit, 63, 115-6 Röntgen rays, discovery, 157; ethereal nature, 158, 176; electronic effects, 163; suggested connection with gravity, 176 Rothmann, early notice of the zodiacal light, 256 Russell, photographs of Magellanic Clouds, 213 Rutherford, atomic disintegration, 162 Satellites, periods of revolution, 46; anomalies of movement, 47-8, 52, 96, 236-9; effects on of tidal friction, 93-4, 96, 97, 238; origin by fission, 105; 'asteroidal,' 239-40 Saturnian system, an example to cosmogonists, 41, 71; anomalies, 49, 52, 96, 237-240 Schaeberle, photographs of nebulous spirals, 204, 212 Secchi, star-classification, 219 See, tidal friction in stellar systems, 98, 142 Shelley's Demiorgon, 9 Solar system, origin, 22, 39-42, 69-82, 241; anomalies, 29, 43-52, 236-241; mechanism, 30, 234-5; stability, 235, 242; springs of decadence, 243-5; translation, 245-8 Spectroscopic binaries, 98, 112-114, 142-4, 221 Spencer, status of nebulæ, 54; spontaneous generation, 270 Spinoza, pantheistic views, 9 Stars, relations to nebulæ, 35-6, 202-3; distribution, 147; relative ages, 217-221, 225; spectra, 221-5 Stokes, Sir George, nature of life, 276 Stoney, criticism of gravitational hypothesis, 179 Sun, mode of development, 25, 31; maintenance of heat, 31-5; helium-constituent, 55-6; stellar relationships, 224-5; actual standing, 232-3; motion in space, 245-8 Swedenborg, cosmic evolution, 4, 6, 15 Thales, ideas of cosmic evolution, 4, 14, 151 Thomson, J. J., mass of corpuscles, 158; gravitational effects, 173; Röntgen rays and gravity, 176; ether and matter, 190 Tidal friction, effects in earth-moon system, 28, 87-92, 94, 97, 244; in other sub-systems, 48, 50, 93-7, 238-9; on binary stars, 98-9, 108, 142; modifying power, 46-7, 67-8, 83-7 Tisserand, transmission-rate of gravity, 175 Uranian system, retrograde motion, 43, 52, 70, 237