clxxviii INDEX. 



of Asia, p. 340; Kamschatka and Aleutian Islands, p. 350, 353354, 388; 

 Pacific Ocean, p. 373 and 382 ; New Zealand, p. 380. 



Fitz Roy, p. 75. 



Fogo : Volcano of the Ilha do Fogo, p. 257, 329 and Note 351. 



Force, magnetic, points of greatest, p. 92, 95 ; line of least, p. 92, 101, 505 ; de- 

 crease in ascending above the earth's surface, p. 102 105 ; measures of its 

 variations first suggested by Borda, p. 63; first executed by La Perouse's 

 expedition, 1785 1787, p. 63; its variations first made known by Huinboldt, 

 p. 63; Sabine's map of, p. 77 ; diurnal variation of, p. 106 and 112117. 



Formosa, Island of, p. 350, 361, and Note 489. 



Foster, magnetic observations, p. 105, 129 ; pendulum experiments, p. 472 479. 



Franklin Bay, flames seen in, p. 482. 



Fremont, the Rocky Mountains, p. 396. 



Fumaroles, in Tuscany, the Caucasus, and Iceland, p. 209211, and generally, 

 Note 555. 



Fuss, p. 74. 



Galapagos Islands, volcanic action in, p. 385 and Note 527. 

 Galera Zaml>a, submarine eruption at, p. 215 and Note 294. 

 Gaseous springs and exhalations, p. 206221 ; Italian, p. 209 and 420, Note 289; 



Icelandic, p. 210 and 420 ; American, p. 211 ; Chinese, p. 216 and 336; Javan, 



p. 217; general remarks on volcanic gases, p. 420 421. 

 Gauss, terrestrial magnetism, p. 64, 75 and 86, 93, 485487, 494. 

 Gay-Lussac, p. 104 and 118; earthquakes, Note 239. 

 Gay (Claudio), p. 81. 

 Geothermal lines, p. 189. 

 Gerolstein, p. 230. 

 Gey sir, p. 200, Note 274. 

 Gilliss, p. 82, Note 154 and 155. 



Gilbert (William), on terrestrial magnetism, p. 5859, and Note 59. 

 Gilpin, p. 64. 



Graham, early observations on magnetic variations, p. 126, and Note 151. 

 Granite, fusion-temperature of, p. 244, and Note 464. 

 Greenwich magnetic observations, p. 83. 

 Grenelle, Artesian well of, p. 35. 



Haidberg, magnetic rock of the, p. 160, and Note 224. 



Halley, terrestrial magnetism, p. 6061, Aurora, 135, and Note 167. 



Hallmann, temperature of springs, p. 205, and Note 284. 



Hansteen, terrestrial magnetism, p. 68, 69, 72, 119 ; movement of magnetic lines, 



p. 152. 



Hawaii, Island of, p. 374377. 

 Heat, internal, of the earth, p 3448, and Note 234. 

 Hecla, p. 241, 250, and 329. 

 Himalaya, p. 282. 



Hopkins, on the depth of the solid crust of the globe, Note 234. 

 Hornblende, p. 439. 



Hornitos, the, of Jorullo, p. 296-298, 302. 



Ho-tsing, Chinese " fire-springs" of combustible gas, p. 216217. 

 Humboldt, magnetic observations, p. 65-67, 71, 73, 77, 94-96, 103, 118124, 



and Notes 1 1 1 and 128. 

 Hypsometric tables, of volcanoes, p. 245248 ; of Mexican volcanoes, p. 269 ; of 



places in Mexico, p. 392 ; in the Rocky Mountains, p. 400402. 



