Andromeda (constellation), 279, 314; Great Nebula in, 314, 316 Andromedid meteors, 272 Anglo-Saxon Chronicle, 87-88 Anighito meteorite, 277 Annular eclipse, 65-68, 80, 92, 99 Annular Nebula in Lyra, 315-316 Annulus, 68 Ansæ, 242-243 Anticipation in discovery, 236-237 Apennines, Lunar, 200 Aphelion, 274 Apparent enlargement of celestial objects, 192-196 Apparent size of celestial objects deceptive, 196, 294 Apparent sizes of sun and moon, variations in, 67, 80, 178 Aquila (constellation), 295 Arabian astronomers, 107, 307 Arago, 92, 257 Arc, degrees minutes and seconds of, 60 Arcturus, 280, 282, 290, 295 Argelander, 290 Argo (constellation), 298 Aristarchus of Samos, 171 Aristarchus (lunar crater), 205 Aristophanes, 101 Aristotle, 161, 173, 185 Arrhenius 222, 253-254 Assyrian tablet, 84 Asteroidal zone, analogy of, to Saturn's rings, 238 Asteroids (or minor planets), 30-31, 225-228, 336; discovery of the, 23, 244; Wolf's method of discovering, 226-227 Astrology, 56 _Astronomical Essays_, 63, 337 Astronomical Society, Royal, 144 _Astronomy, Manual of_, 166 Atlantic Ocean, parallelism of opposite shores, 340-341 Atlas, the Titan, 18 Atmosphere, absorption by earth's, 129-130; ascertainment of, by spectroscope, 124-125, 212; height of earth's, 167, 267; of asteroids, 226; of earth, 129, 130, 166-169, 218, 222, 267, 346; of Mars, 156, 212, 216; of Mercury, 156; of moon, 70-71, 156, 201-203; of Jupiter, 231; of planets, 125; of Saturn's rings, 239 "Atmosphere" of the stars, 331 Atmospheric layer and "glass-house" compared, 167, 203 August Meteors (Perseids), 270 Auriga (constellation), 294-296, 306, 311; New Star in, 311 Aurigæ, [b] (Beta), 294, 297, 304 Aurora Borealis, 141, 143, 259 Australia, suggested origin of, 340 Axis, 29-30; of earth, 163, 180; small movement of earth's, 180-181 Babylonian tablet, 84 Babylonian idea of the moon, 185 Bacon, Roger, 108 Bacubirito meteorite, 277 Bagdad, 107 Baily, Francis, 92 "Baily's Beads," 69, 70, 91-92, 154 Bailly (lunar crater), 199 Ball, Sir Robert, 271 Barnard, E.E., 31, 224, 232-234, 237, 258 "Bay of Rainbows," 197 Bayer's classification of stars, 289, 291-292 Bayeux Tapestry, 263 Bear, Great (constellation). _See_ Ursa Major; Little, _see_ Ursa Minor Beehive (Præsepe), 307 Beer, 206 Belopolsky, 304 "Belt" of Orion, 297 Belt theory of Milky Way, 321 Belts of Jupiter, 230 Bergstrand, 314 Berlin star chart, 244 Bessel, 173, 280, 305 Beta ([b]) Lyræ, 307 Beta ([b]) Persei. _See_ Algol Betelgeux, 297 Bible, eclipses in, 85 Biela's Comet, 256-257, 272-273, 345 Bielids, 270, 272-273 Billion, 51-52 Binary stars, spectroscopic, 301-306, 309; visual, 300, 303-306 "Black Drop," 152-154 "Black Hour," 89