discovered annually, 537 ; re- 

 appearance of Halley's Comet, 

 539 ; Chinese statements, 539 ; 

 Comet of Aristotle, 541 ; tails of 

 comets, 544, 548 ; radiant heat, 

 546; Lexell's Comet, 547; Biela's 

 Comet, 550 ; numerical data, 

 553 ; elements of the six interior 

 comets, 555 ; inclination of the 

 orbits, 557; Chaldean opinions 

 on, 559. 



Craters of the Moon, 497. 



Crema, great fall of aerolites at, 587. 



Cusa, Cardinal de, his remarkable 

 views of the physical constitution 

 of the Sun, 364; on the motion 

 of the Earth, 366. 



Cygnus, nebula in, 339. 



D'Arrest's Comet, elements, 555. 

 Days and hours, planetary, 411. 

 December, falling stars in, 582. 

 De Hoces discovers the southern ex 



tremity of the new continent, 



339. 



Densities of the planets, 446. 

 De Vico's Comet, elements, 555. 

 Dione, a satellite of Saturn, 523. 

 Distances of the planets from the 



Sun, 429. 



Double nebulae, 320. 

 Double stars differ in their natural 



character from our solar system, 



351. 

 Dunlop, his observations of nebulae 



at Paramatta, 304, 311. 



Earth, the, distance, and other nu- 

 merical data, 476 j nutation, 427, 

 454. 



Earth-light, what, 480 ; known to 

 Leonardo da Vinci, 483. 



Egeria, discovery of, 421; elements, 

 508. 



Elliptical nebulas, named the normal 

 type, 318. 



Enceladus, a satellite of Saturn, 

 523. 



Encke's Comet, elements, 555 ; its 

 re -appearance, 556. 



Epochs, main, of planetary dis- 

 covery, 357. 



Excentricity of the planetary 

 orbits, 457. 



Exterior planets, 424. 



Fabricius first observes the solar 



spots, 367. 



Facula? and shallows, 399. 

 Page's Comet, elements, 555. 

 Falling stars, 566. 

 Faraday on atmospheric magnetism, 



395. 



Fireballs, 556. 

 Flora, discovery of, 421 ; elements, 



508. 

 Fontaney, the Jesuit, on the Magel- 



lanic Clouds, 342. 



Galileo, his controversy with Marius, 



295; his Mundus Jovialis, 296; 



use of coloured glasses neglected 



by, 368. 

 Geminus mentions nebulous stars, 



293. 

 Gnomons, ancient, 457. 



Halley's observations on nebulse, 

 299. 



Halby's Comet, re -appearances of, 

 539. 



Heat, rays of, 395. 



Heat possessed by the Moon's light, 

 479. 



Hebe, discovery of, 421 ; elements, 

 508. 



Heis's observations on shooting 

 stars, 576. 



Herschel, Sir William, his estimate 

 of the extent of nebulous spots, 

 292 ; his discoveries, 302 ; on 

 the nebula of Orion, 331 ; on 

 solar spots, 371 ; opposed to the 

 assumption of a lunar atmo- 

 sphere, 486. 



Herschel, Sir John, on nebulse and 

 stellar clusters, 312, 318; on 

 irregular nebulous masses, 324 ; 

 on the nebula in Orion, 329 ; on 

 the nebula round r) Argfts, 332 j 



