r 4 ] 



connected with one another, 343 ; 

 nor with the Milky Way, 343. 



Magnitude, absolute and apparent, 

 of planets, 426. 



Map of the Moon, 490. 



Mars, numerical data, 502; meteo- 

 rological analogies with tlie 

 Earth, 503. 



Masses of the planets, 445. 



May, failing stars in, 579. 



Mayer, of Gunzenhausen (Simon 

 Marias), first describes a nebula, 

 295. 



Mercury, distance, diameter, mass, 

 density of, 470. 



Messier, his discoveries regarding 

 nebulae, 302. 



Meteor asteroids, 357. 



Meteoric stones, 556 ; seldom fall 

 from a clear sky, 587; remark- 

 able falls of, 587; analysis, 

 592. 



Metis, discovery of, 421 ; elements, 

 508. 



Michell conceives all nebulae to be 

 stellar clusters, 302- 



Milky Way, Huygens on the, 328. 



Mimas, a satellite of Saturn, 523. 



Moon, myths respecting the, 438, 

 440; estimate of the heat of its 

 surface, 461 ; numerical data, 

 477; moonlight, 477; capable of 

 producing heat, 479; styled by 

 the Indians, King of the stars of 

 cold, 479; eclipses, 483; predic- 

 tions from the colour of the 

 eclipsed body, 485; lunar twi- 

 light disproved, 486; probably a 

 voiceless wilderness, 487 ; irradia- 

 tion, 487; spots, 488; supposed 

 to reflect the surface of our 

 planet, 489; topographical chart, 

 490; so-called seas, 491; moun- 

 tains, 493; comparison of height 

 with the mountains of the Earth, 

 494 ; ray-systems, 495; annular 

 plains, 495 ; craters of elevation, 

 497; rills, 499; influence on the 

 Earth, 500. 



Mountains of the Moon, 493. 



Mundus Jovialis, a work by Galileo, 

 295. 



Nebula, the first isolated, dis- 

 covered, 295. 



Nebulae, Lacaille's classification of, 

 300 ; discoveries of the Herschels, 

 302; of the Earl of Rosse and 

 others, 304 ; probably no essen- 

 tial physical distinction between, 

 and clusters of stars, 305 ; ques- 

 tion of the existence or non- 

 existence of a self-luminous, 

 vaporous matter, 307; elliptical, 

 318; annular, 319; planetary, 

 320; nebulous stars, 322; galaxy 

 of, not confirmed by recent ob- 

 servation, 325. 



Nebular theory, the, 301; inde- 

 pendent of the theory of sidereal 

 aggregation, 303. 



Nebulous masses, regular, 315; ir- 

 regular, 321; these latter mostly 

 situate near the Milky Way, 

 322; extraordinary size of some, 

 and singular forms of others, 

 326. 



Nebulous spots, 291; number whose 

 positions have been determined, 

 292 ; early notices of, 293 ; Ga- 

 lileo's discoveries, 297; Huygens, 

 299; Lacaille, 300; other inves- 

 tigators, 301 ; the discoveries of 

 the Herschels, 302; the Earl of 

 Rosse, 304 ; Sir John Herschel's 

 distribution of, 312. 



Nebulous stars, mentioned by Hip- 

 parchus, Geminus, and Ptolemy, 

 293 ; a modern division of regu- 

 lar nebulae, 322. 



Neptune, considerations on the dis- 

 tance of, 528 ; numerical diita, 

 528 ; claims to the discovery of, 

 529. 



Neptune, satellites of, 531. 



Northern Catalogue of the Her- 

 schels, 309. 



Northern hemisphere possesses 

 many nebulae, and but few clus- 

 teis of stars, 311. 



