(Polaris) [alpha] : 1 h. 22 m. + 88° 46′ : 2-9 : 215·6° : 18·22″. Yellow, bluish, test for 2-inch. VIRGO. [Sigma] 1670 or [gamma] : 12 h. 37 m. - 0° 54′ : 3-3 : 328·3° : 5·94″. Both pale yellow. Binary, 185 years. VULPECULA. M. 27 : 19 h. 55 m. + 22° 27′. The Dumb-bell Nebula. Just visible with 1-1/4-inch. Gaseous. INDEX A Achromatic. See Telescope Adams, search for Neptune, 198-201 Aerolites, 227 Airy, search for Neptune, 197-201 Albireo, colour of, 236 Alcor, 241 Alcyone, 256 Aldebaran, 234; colour of, 235 Algol, spectroscopic binary, 246; diameter and mass of components, 246; period of, 250; variables, 250 Alps, lunar, 116; valley of, 116, 117 Altai Mountains, 117 Altair, 234 Altazimuth, 25-28 Anderson discovers Nova Aurigæ, 253; discovers Nova Persei, 254 Andromeda, great nebula of, 263, 264 Andromedæ [gamma], colour of, 236 Andromedes, 214, 215, 225, 226 Annular eclipse, 69, 70 Antares, 234 Anthelme observes new star, 252 Apennines, lunar, 116 Archimedes, 117 Arcturus, 234 Argelander, number of stars, 235 Ariadæus cleft, 119 Arided, 234 Arietis [gamma], observed by Hooke, 240 Aristillus, 117 Asteroids, number of, 150; methods of discovery, 150, 151 Asterope, 256 Astræa, discovery of, 150 Atlas, 256 Atmosphere, solar, 75 Autolycus, 117 Auzout, aerial telescopes, 4 B Bacon, Roger, 1 Bailey, cluster variables, 259 Ball, Sir R., 154, 262; 'Popular Guide to the Heavens,' 278 Barnard, measures of Venus, 89; markings on Venus, 95; on Mars, 133; measures of asteroids, 152; discovers Jupiter's fifth satellite, 167; measures of Saturn, 172; drawing of Saturn, 172; rotation of Saturn, 174; on Saturnian markings, 184-185; observation of Comet 1882 (iii.), 218 Bayer, lettering of stars, 278 Beer. See Mädler Bélopolsky, rotation of Venus, 96 Bessel, search for Neptune, 197 Betelgeux, 234; colour of, 235 Biela's comet, 213, 214, 215, 224, 225 Birmingham observes Nova Coronæ, 252 Bode's law, 148, 149 Bond, G. P., discovers rifts in Andromeda nebula, 264 Bond, W. C., discovers Crape Ring, 178; discovers Saturn's eighth satellite, 187; verifies discovery of Neptune's satellite, 201 Boötis [epsilon], double star, 242 Bouvard, tables of Uranus, 197 Bradley uses aerial telescope, 4 Bremiker's star-charts, 200 Brooks' comet, 210; observation of comet 1882 (iii.), 218 Brorsen's comet, 213 C Calcium in chromosphere, 73 Campbell, atmosphere of Mars, 140; bright projections on Mars, 141; spectroscopic investigation of Saturn's rings, 180 Canals. See Mars Canes Venatici, great spiral nebula in, 265 Canopus, 234 Capella, 234 Capricorni [alpha], naked-eye double, 241 Carpathians, 117 Carrington, solar rotation, 59