INDEX. 



455 



distinguished, but improperly, aa Plu- 

 tonic and Volcanic, 1T4; three groups 

 of phenomena which indicate the exist- 

 ence of one general cause, 176; list of 

 memorable examples of these phenome- 

 na, 1T6. 



Sarth-waves in volcanic phenomena, 165. 

 Eastern Asia, volcanoes of the islands of, 



344. 

 Edgecombe, Mount, a volcano, 255, 391 ; 



another in New Zealand, 372. 

 Edinburgh, beautiful aurora observed at. 



153. 



Edrisi on the land of Gog and Magog, 337. 

 Crust of the earth, considerations on its Eifel, extinct volcanoes of the, 221 ; two 



varying thickness, 410. 

 Crystallized minerals of the Maars, 224; 

 greater number found on Vesuvius, 224. 

 Cueva de Antisana, 312. 



Corcovado, Volcan de, 274. 



Cordilleras. See Andes. 



Corea, volcanoes of, 353. 



Cosima, small elevation of the volcano of, 



234. 

 Costa, Colonel A., his experiments on 



mean annual temperature, 43. 

 Cotopaxi, mineralogical composition of, 



322. 

 Craters of elevation, 215; distinguished 



from true volcanoes, 217. See, also, 



Volcanoes. 

 Crozet's group, traces of former volcanic 



action in, 362. 



kinds of volcanic activity distinguish- 

 able, 222; Mitscherlich on the minerals, 

 224; Ehrenberg on the infusoria, 227. 



Elburuz, as an extinct volcano, 339. 



Elevation, question of the influence of, on 

 magnetic dip and intensity, 111 j craters 

 of, distinguished from true volcanoes, 

 217. 



Elias, Mount, a volcano, 239, 391. 



Elliot, Captain, on the magnetic equator, 

 104. 



Ellipticity of the earth, speculations of the 

 ancients on the, 29; Bessel's determina- 

 tion, 29. 



El Nuevo, a volcano, 2GO. 

 Dechen, H. von, on volcanic phenomena El Viejo, a volcano, measurements of, 260. 



Cyclades, volcanic phenomena in the, 254. 



Dana, James, his valuable researches in 

 the Pacific, 364; his grouping of the ba- 

 saltic and coral islands, 365 ; and the vol- 

 canoes of the Sandwich Islands, 367. 



Darwin, Charles, his enlarged views on 

 earthquakes and eruptions of volcanoes, 

 272; general acknowledgment of obliga- 

 tions of science to, 364. 



Dasar, sand lakes of, 449. 



in the Eifel, 226. 

 Declination. See Magnetism. 

 Degree, table of the increase in length 



the, from the equator to the pole, 21. 

 Demavend, volcano of, 335; question of 



its altitude, 334. 

 Density of the earth, experiments to de 



termine, 33; Airy's results, 35. 

 Detritus dikes, 311. 



mass in certain volcanoes, 432. 

 Devonian slate, 221. 

 Diablo, Monte del, in California, 389. 

 Diamagnetism, its discovery by Faraday, 



51, 77. 

 Dio Cassius on the eruptions of Vesuvius, 



399. 

 Diodorus Siculus on the Phlegrsean Fields, 



Disturbances, magnetic, table of, 130. 



Djebel el Tir, a volcano, 334. 



Dome-shaped and bell-shaped mountains, 

 peculiar aspect given by, to the land- 

 scape, 218. 



Domite, origin of the term, 421. 



Dry fog of the summer of 1783, 393. 



Duperrey, his observations on the mag- 

 netic equator, 103. 



Earth, its size, configuration, and density, 

 14, 35 ; interior heat, 37, 234 ; magnetic 



El Volcancito, now a mountain of ashes, 

 302. 



Emanations from fumaroles, their nature, 

 396. 



Enceladus. See Typhon. 



England, volcanic phenomena in, 329, 450. 



Equator, magnetic. See Magnetic Equa- 

 tor. 



Erebus, Mount, the volcano, 101, 237. 



Deville, on the structure and color of the Erman on the magnetic equator, 103 ; his 



researches on the volcanoes of Kamt- 

 schatka, 340. 



Erupted blocks, 446. 



Eruption, masses of, considerations on, 

 215; craters of, 216. 



Eruptions of volcanoes, considerations on 

 the general laws of, 243; varying heights 

 to which matters are cast, 251. 



Euboea, Strabo's description of an earth- 

 quake in, 215. 



Europe, active volcanoes of, 328; extinct 

 volcanoes and volcanic phenomena, 221, 

 227, 329, 450. 



Fairweather, Mount, a volcano, 391.- 

 Faraday's discovery of the paramagnetic 



force of oxygen, 78; important results 



expected from it, 81, 98; on diamagnet- 



ism, 51, 78. 

 Feldspar, variety of minerals comprised 



under the denomination of, 427, 442. 



activity, 50; magnetic storms, 137; po- Ferdinandea, the volcanic island, 328. 

 lar light, 146; reaction of the interior on -Figure of the earth, attempts to solve the 

 the surface, 157 (see, also, Earthquakes, problem, 18 ; determinations of Bessel, 

 Volcanoes) ; thickness of the crust of, j 19 ; earlier observations, 20. 

 probably very unequal, 163. j Fissures caused by earthquake?, 166; vol- 



Earthquakes, variety of views as to their canic, 216, 218 ; volcanoes upheaved on 

 cause, 162 ; the impulse, 162 ; trans- fissures, 252. See Volcanoes, 

 latory movements, 167; subterranean Fitzroy's magnetic observations, 71. 

 noises, 171 ; velocity of propagation, 172; iFloods in rivers, prognostication of, 180. 



