409 



Material unity of the Universe, 263 

 Mercury, rotation and revolution, 



145 



Schiaparelli, 145-146 

 constant face to the sun, 146 

 tidal action on, 148 

 early discovery of, 197 

 Meteoric dust, 208-209 



debris on the globe, 230 

 Meteors, influx of into the sun, 21- 



23 

 thooting-star, autobiography of, 



203-209 



constitution of, 203 

 flight, 203, 215 

 wanderings in space, 204 

 combustion, 207 

 height of, 209, 210, 213 

 Mr. "W. F. Denning' s ob- 

 servations, 211-214 

 fireballs of 1877-8, 217 



1879, at York, 218, 219 

 1876, in America, 220 

 brilliancy of, 218 

 detonation, 221 

 energy of, compared with 



powder, 223, 224 

 energy of, compared with 



steam, 224 

 luminous trails of, 225- 



227 



ttar showers, 228 

 periodicity of, 235, 237 

 early records of showers, 236 

 telescopic shooting stars, 229, 



230 

 November showers of 1866, 



231-234 

 November showers of 1698, 



237 



Leonids, 238, 242 

 the Great Shoal, 238-246 

 its width, 239 

 its intersection of earth's 



orbit, 242, 245 

 Perseids and Andromedes, 



245 



Milky Way, 121 



Months, future, of 1,400 hours, 73 

 Moon, smallest of visible orbs, 49 

 dimensions, 50 

 unchanging face, 62 

 dark aide of, 53-55 



Moon (continued) 



rotation on axis, 55-57 



the rotation paradox, 56 



revolution, 57 



lunar history, 57 



ancient heated condition, 58 



cooling of, 61 



active lunar volcanoes, 58 



lunar tides, 58-62 



their effect, 63 

 absence of water on the, 69 

 of life, 84 

 of ice, 85 

 of air, 86, 88 

 what became of lunar water, 



85 



and terrestrial tides, 63, 74 

 and earth's speed of rotation. 



67 

 recession of, from the earth, 



67 

 ancient propinquity to earth, 



68 



mountains on, 90 

 craters, 90 



the crater Ptolemy, 75 

 why does the moon not fall? 



78, 79 



non-luminous, 80 

 earth seen from, 82, 95 

 old, in new moon's arms, 82 

 whether inhabited, 82 

 through the telescope, 83, 84 

 indications of gaseous material 



on, 87 



weights on, 94 

 origin of, 69-71 

 future career, 71-73 



N 



NATURAL Selection, 345, 355-356 

 Nebula in Andromeda, 124, 315- 

 317 



Great Spiral, 140 



Orion, 127, 128, 133, 265, 317 



Huggins' discoveries, 134, 136 

 Nebula;, 124, 125, 132 



and spectrum analysis, 137 



Newton's discoveries, 77, 79-80 



Niagara, debt of, to the sun, 46 



November star showers (ttt 



Meteors) 



B B 



