INDEX TO VOL. III. 



Acnaoaf atic telescopes, 63. 



Adalbert, Prince, of Prussia, his observa- 

 tions on the undulation of the stars, 59. 



Alcor, a star of the constellation Ursa Ma- 

 jor, employed by the Persians as a test 

 of vision, 49, 50, 200. 



Alcyone, one of the Pleiades, imagined 

 the center of gravity of the solar sys- 

 tem by Madler, 198. 



Alphonsine Tables, date of their construc- 

 tion, 151. 



Anaxagoras of Clazomenae, his theory 

 of the world-arranging intelligence, 11 ; 

 origin of the modern theories of rota- 

 tory motion, 12. 



Andromeda's girdle, nebula in, 142. 



Arago, M., letters and communications of, 

 to M. Humboldt, 46, 49, 67, 68, 73, 96, 

 207-209 ; on the effect of telescopes on 

 the visibility of the stars, 69 ; on the 

 velocity of light, 80, 84 ; on photometry, 

 92, 96 ; his cyanometer, 97. 



Aratus, a fragment of the work of Hip- 

 parchw preserved in, 109. 



Archimedes, his " Arenarius," 30. 



Arcturus, true diameter of, 89. 



Argelander, his view of the number of 

 the fixed stars, 105, 106 ; his additions 

 to Bessel's Catalogue, 115 ; on period- 

 ically variable stars,. 166. 



rj Argus, changes in color and brilliancy 

 of, 135, 178, 179. 



Aristotle, his distinct apprehension of the 

 unity of nature, 13-15; his defective 

 solution of the problem, 15; doubts the 

 infinity of space, 29, 30 ; his idea of the 

 generation of heat by the movement of 

 the spheres, 124. 



Astrognosy, the domain of the fixed stars, 

 26-28. 



Astronomy, the observation of groups of 

 fixed stars, the first step in, 118 ; very 

 bright single stars, the first named, 89. 



Atmosphere, limits of the, 40, 41 ; effects 

 of an untransparent, 104. 



Augustine, St., cosmical views of, 124. 



Autolycus of Pitane, era of, 89, 90. 



Auzout's object-glasses, 62. 



Bacon, Lord, the earliest views on the ve- 

 locity of light found in his "Novum 

 Organum," 79. 



Baily, Francis, his revision of De Lalande's 

 Catalogue, 115. 



Bayer's lettering of the stars of any con- 

 stellation not an evidence of their rel- 

 ative brightness, 98. 



Berard, Captain, on the change of color 

 of the star y Cruris, 135. 



Berlin Academy, star maps of the, tit. 



Bessel, on repulsive force, 34, 35 ; his star 

 maps have been the principal means of 

 the recognition of seven new planeta, 

 116 ; calculation of the orbits of double 

 stars by, 211. 



Binary stars, 199. 



Blue stars, 136 ; less frequent than red, 209. 



Blue and green suns, the probable cause 

 of their color, 208. 



Bond, of the Cambridge Observatory, 

 United States, his resolution of the neb- 

 ula in Andromeda's girdle into small 

 stars, 142. 



Brewster, Sir David, on the dark lines of 

 the prismatic spectra, 44. 



British Association, their edition of La- 

 lande's Catalogue, 115. 



Bruno, Giordano, his cosmical views, 17 ; 

 his martyrdom, 17. 



Busch, Dr., his estimate of the velocity of 

 light incorrect, 82. 



Catalogues, astronomical, their great im- 

 portance, 113, 114 ; future discoveries 

 of planetary bodies mainly dependent 

 on their completeness, 114 ; list of, 114, 

 115 ; Halley's, Flamstead's, and others, 

 114 ; Lalande's, Harding's, Bessel's, 115 



Catagterisms of Eratosthenes, 89, 90. 



a Centauri, Piazzi Smyth on, 146, 147, 185 ; 

 the nearest of the fixed stars that have 

 yet been measured, 191, 192. 



Central body for the whole sidereal heav- 

 ens, existence of, doubtful, 197. 



Chinese record of extraordinary stars (of 

 Ma-tuan-lin), 109, 155-159; deserving of 

 confidence, 162. 



Clusters of stars, or stellar swarms, 140 ,- 

 list of the principal, 141-143. 



Coal-sacks, a portion of the Milky Way in 

 the southern hemisphere so called, 137. 



Colored rings afford a direct measure of 

 the intensity of light, 96. 



Colored stars, 130; evidence of change 

 of color in some, 131, 132 ; Sir John 

 Herschel's hypothesis, 131 ; difference 

 of color usually accompanied by differ- 

 ence of brightness, 209. 



Comets, information regarding celestial 

 space, derived from observation on, 31, 

 39 ; number of visible ones, 151. 



Concentric rings of stars, a view favored 

 by recent observation, 149. 



Constellations, arrangement of stars into, 

 very gradual, 119. 



Contrasted colors of double stars, 207. 



Cosmical contemplation, extension of, i* 

 the Middle Ages, 16. 



