Jerschel, Sir John, on the trans- 

 mission of liaht, 34; on the in- 

 fluence of the sun's rays, 40; 

 compares the sun to a perpetual 

 northern light, 40; on the atmo- 

 sphere, 45; on the blackness of 

 the ground of the heavens, 47; 

 on stars seen in daylight, 73 ; on 

 photometry, 125; photometric 

 arrangement of the fixed stars, 

 132; on the number of stars 

 actually registered, 142; on the 

 cause of the red colour of Sirius, 

 177; on the Milky Way, 196; 

 on the sun's place, 203; on the 

 determined periods of variable 

 stars, 225 ; number of double 

 stars the elements of whose orbits 

 have been determined, 287. 

 Hieroglyphical signification of a 

 star, according to Horapollo, 173. 

 Hind's discovery of a new reddish- 

 yellow star of the 5th magnitude, 

 in Ophiuchus, 217; has since 

 sunk to the llth magnitude, 

 217; calculation of the orbits of 

 double stars by, 287. 

 Hipparchus, on the numbej of the 

 Pleiades, 60; his catalogue con- 

 tains the earliest determination 

 of the classes of magnitude of the 

 stars, 120; a fragment of his 

 work preserved to us in Aratus, 

 147. 

 Holtzmann, on the Indian zodiacs, 



163. 



Homer, not an authority on the 

 state of Greek astronomy in His 

 day, 160, 166. 



Humboldt, Alexander von, works 

 of, quoted in various notes: 

 Ansichten der Natur, 105. 

 Asie Centrale, 150. 

 ^ssai sur la Geographic des 



Plantes, 75. 

 Examen critique de 1'Histoire 



de la Geographic, 61, 151. 

 Lcttre a M. Schumacher, 123, 

 183. 



Recueil d' Observations Astro- 



nomiques, 54, 59, 123. 

 Relation Historique du Voyage 

 aux Regionsequinoxiales, 72, 

 75, 105, 123. 



Vue des Cordilleres et Monu- 

 mens des Peuples indigenes 

 de 1'Amerique, 162, 180. 

 Humboldt, Wilhelm von, quoted, 28. 

 Huygens, Christian, his ambitious 

 but unsatisfactory Cosmotheus, 

 22; examined the Milky Way, 

 195. 



Huygens, Constantine, his improve- 

 ments in the telescope, 80. 

 Hveigelmir, the cauldron-spring of 

 the Edda-Songs, 5. 



Indian fiction regarding the stars of 

 the Southern hemisphere, 187. 



Indian theory of the five elements 

 (Pantschata], 36. 



Indian zodiacs, their high antiquity 

 doubtful, 163. 



Jacob, Capt., on the intensity of 

 light in the Milky Way, 198; 

 calculation of the orbits of double 

 stars, by, 287. 



Joannes Philoponus, on gravitation, 

 19. 



Jupiter's satellites, estimate of the 

 magnitudes of, 64 ; case in which 

 they were visible by the naked 

 eye, 66; occultations of, observed 

 by daylight, 80. 



Kepler, his approach to the mathe- 

 matical application of the theory 

 of gravitation, 18; rejects the 

 idea of solid orbs, 169. 



Lalande, his Catalogue, revised by 



Baily, 155. 

 Lassel's telescope, discoveries made 



by means of, 85. 

 Lepsius, on the Egyptian name 



(Sothis) of Sirius, 180. 

 Leslie's photometer, defects of, 129. 

 Libra, the constellation, date of its 



