Earth, relation to planets, 11–15, 19; nearness to sun, 19; terrestrial planet, 41; movement of, 51; position in regard to Mercury, 120–121; likeness to Venus, 138–140. Enceladus, satellite of Saturn, 222. Encke’s comet, 109. Equinox, derivation of word, 74. Eros, small planet, 255–256. Europa, satellite of Jupiter, 200–201. Flagstaff, Arizona, observatory of, 175–176. Fomalhaut, 187, 209, 213. Galileo, 136. Ganymede, satellite of Jupiter, 200–201, 205. Gemini, constellation of the zodiac, 76, 81–82, 91–92, 188, 210–211, 213. George III., Uranus first called _Georgium Sidus_ after, 226. Great Dipper, 73, 77, 84, 96, 104, 105, 186, 236. Hamal, star in constellation of Aries, 78. Herschel, discovery of Uranus by, 226–227, 232. Hyades, the, 79. Hyperion, satellite of Saturn, 222. Inferior planets, 40. Io, satellite of Jupiter, 200, 201. Japetus, satellite of Saturn, 222. Juno, planetoid, 251, 253. Jupiter, color, 5; attraction between Saturn and, 15; distance from sun, 19; size and importance of, 20; movement, 25, 65; satellites, 34, 106, 199–205; long known, 38; superior planet, 41; space between Mars and, 42; influence on comets, 44; gibbous, 66; distance from ecliptic, 72; near Antares, 86; in Scorpio, 127; size and velocity, 183–185; place in sky, 186–190; distance, light, and heat, 190–193; seasons and atmosphere, 193–195; surface features, 195–199; symbol, 205; compared to Saturn, 213–214, 215–218; nearness of asteroids to, 244; how to recognize, 259–264. Laplace, nebulæ hypothesis of, 28, 30. Leo, constellation of zodiac, 76, 82–83, 91–92, 188, 211–212, 221. Leverrier, discovery of Neptune by, 236–238. Libra, constellation of zodiac, 76, 85, 91–92, 188, 212. Little Dipper of the Pleiades, 79. Lyre, constellation of the, 54. Major planets, 19. Mars, “eye” of, 12; distance from sun, 19; nearness to earth, 20; movement of, 25, 65; long known, 38; superior planet, 41; space between Jupiter and, 42; speed, 51; gibbous, 66; distance from ecliptic, 72; color, 80, 86, 259; position in regard to Antares, 87; density, 110; nearness to Venus, 128; variety in brightness, 151–152; how and where to identify, 152–162, 259–265; size, atmosphere, and temperature, 162–165; distance and brilliancy, 166–170; seasons, 170–171; surface aspect, 172–179; satellites, 180–181; symbol of, 182; nearness of asteroids to, 244; Bode’s law and, 245–246, 248–249; smallness, 260.