Stars, proved to be suns, 32; invisible, 39; classification of, 33; spectroscopic double, 42; distribution of the, 47; number of visible, 48; description of Milky Way, 52; in relation to Milky Way, 59; distances of, 74; measurement of distance of, 85; mass of binary, 97; evolution of double, 122; spectroscopic double, 123; clusters of, 125; evolution of the, 128; classification of, 130; the hottest, 131; when cooling give more heat, 132; cycle of evolution and decay, 133; supposed infinite number of, 135; not infinite, 138; law of diminishing numbers of, 149; systematic motions of, 178; in relation to life, 282, 287; possible use of their emanations, 289. Star-clusters and variables, 127. Star-density, diagram of, 66. Star-drift, Proctor on, 176. Starlight, electrical measure of, 290; possible uses of, 292. Star-motions, Prof. Newcomb on, 297. Star-system, limited, 145; stability of, 295; supposed primitive form of, 297. Stellar motion, Luigi d'Auria on, 306. ---- universe, shape of, 49; unity of, 100; evolution of, 103; diagrams of, 300. Stoney, Dr., on atmospheres and gravity, 263. Sun, a typical star, 104; brightness of, 104; heat of, 104; surface of, 105; surroundings of, 106-110; corona of, 108; colour of, 111; elements in, 184. Sun's distance, measure of, 76. ---- heat, supposed limits of, 275. ---- life, all required to develop earth-life, 280. ---- motion through space, 91, 169. ---- ---- uncertain, 177. Sun-spots, nature of, 105. Symmetry of oceans, cause of, 238. Temperature, essential for life, 206; equalised by water, 239; as regards life on planets, 267. Tennyson on man and the universe, 325. Uniformity of matter, 183. Unity of stellar universe, 100. Universe of stars, how its form has affected our sun and earth, 308. Universe not disproportionate if man is its sole product, 320. VENUS, radial motions of, 38; diagram of transit of, 77; life barely possible on, 266; adverse climatic conditions of, 268. WATER, an essential for life, 210; its amount and distribution, 227; an equaliser of temperature, 239. Wave-lengths, how measured, 31. Whewell, on plurality of worlds, 8, 15; on man as the highest product of the universe, 14. Whittaker, Mr. E.T., on gravitative and electro-dynamical forces, 296. Winds, importance of, to life, 246. ZODIACAL light, 109. Printed by T. and A. CONSTABLE, Printers to His Majesty, at the Edinburgh University Press