INDEX. 



455 



Corcovado, Voloan do, 274. 



< lorduleras. Bee Amir,-. 



I'liw, volcanoes of, 353. 



I ima, small elevation of tho volcano of, 



234. 

 .!, Colonel A., his experiments on 



mean annual temperature, 43, 

 Cotopaxi, mineralogical composition of, 



322. 

 (.'raters of elevation, 215; distinguished 



from true volcanoes, 217. See, also, 



Volcanoes. 

 Crozet's group, traces of former volcanic 



action in, 362. 

 Crust of tho earth, considerations on its 



varying thickness, 410. 

 Crystallized minerals of the Ulnars, 224; 



greater number found on Vesuvius, 224. 

 Cueva de Antisana, 312. 

 Cyclades, volcanic phenomena in the, 254. 



Dana, James, his valuable researches in 

 tho Pacific, 364; his grouping of the ba- 

 saltic and coral islands, 305; and the vol- 

 canoes of the Sandwich Islnnds, 3G7. 



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. 



Dechen, H. von, on volcanic phenomena 

 in the Eifel, 226. 



Decimation. See Magnetism. 



1 degree, table of the increase in length of 

 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 residts, 35. 



Detritus dikes, 311. 



Deville, on the structure and color of the 

 mass in certain volcanoes, 432. 



Devonian slate, 221. 



Diablo, Monte del, in California, 389. 



Diamaejnetism, its discovery by Faraday, 

 51, 77. 



Dio Cassius on the eruptions of Vesuvius, 

 399. 



Diodorus Siculus on the Phlegrrean Fields, 

 400. 



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, 21S. 



Domite, origin of the term, 421. 



Dry fog of the summer of 1783, 393. 



Dnperrey, his observations on the mag- 

 netic equator, 103. 



Earth, its size, configuration, and density, 

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

 activity, 5<>; magnetic storms, 137; po- 

 lar light, 146; reaction of the interior on 

 the surface, 157 (see, also, Earthquakes, 

 Volcanoes); thickness of the crust of, 

 probably very unequal, 163. 



Earthquakes, variety of views as to their 

 cause, 162 ; the impulse, 162 ; trans- 

 latory movements, 167; subterranean 

 noises, 171 : velocity of propagation, 172; 



distinguished, hut improperly, as Pla- 

 tonic and Volcanic, 174; three groups 

 Ofphen ena which indicate the i \i t- 



ence of one general cause, 1X6; list of 

 memorable examples of these phenome- 

 na, 176. 



Earth-waves in volcanic phenomena, 1G5. 



I i kern Asia, volcanoes of the islands of, 

 344. 



Edgecombe, Mount, a volcano, 255, 391; 

 another in New Zealand, 372. 



Edinburgh, beautiful aurora observed at, 

 L53. 



Edrisi on the land of Cog and Magog, 337. 



Eifel, extinct volcanoes of the, 221; two 

 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 ; craters 

 of, distinguished from true volcanoes, 

 217. 



Ellas, 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, 260. 



El Viejo, a volcano, measurements of, 260. 



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. 



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. 



Eubcea, Straho's description of an earth- 

 quake in, 215. 



Europe, active volcanoes of, 328; extinct 

 volcanoes and volcanic phenomena, 221, 

 227, 320, 450. 



Fairweather, Mount, a volcano, 391. 



Faraday's discovery of the paramagnetic 

 force of oxygen, 78; important results 

 expected from it, 81, 98; on din-magnet- 

 ism, 51, 78. 



Feldspar, variety of minerals comprised 

 under the denomination of, 427, 442. 



Ferdinandea, the volcanic island, 328. 



Figure of the earth, attempts to solve the 

 problem, 18; determinations of Besscl, 

 V.); earlier observations, 20. 



Fissures caused by earthquake?, 166; vol- 

 canic, 216, 218; volcanoes upheaved on 

 fissures, 252. See Volcanoes. 



Fitzroy's magnetic observations, 71. 



Floods in rivers, prognostication of, 180. 



