e, 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

Aurigae, [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 (Praesepe), 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]) Lyrae, 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

"Black Saturday," 89

Blood, moon in eclipse like, 102

Blue (rays of light), 121, 130

Bode's Law, 22-23, 244-245

Bolometer, 127

Bond, G.P., 236, 257

Bonpland, 270

Booetes (constellation), 295, 314

Bradley, 111

Brahe, Tycho, 290, 311

Bredikhine's theory of comets' tails, 253-254, 256

Bright eclipses of moon, 65, 102

British Association for the