40G 



INDEX. 



208 ; on the magnetic chain of 

 rings, 50. 



Polar light. See Aurora. 



Polarity, the force of, unknown to 

 the Greeks and Romans, 50. 



Poles, magnetic, traditions regard- 

 ing, 55 ; Halley's variation 

 chnrt, 59. 



Polybius, his knowledge of Stron- 



gyle, 257. 

 oly 



Polynesia and similar divisional 

 terms, objected to, 389. 



Pomarape, volcano of, 287. 



Popocatepetl, a volcano, 251 ; 

 meaning of the name, 239 ; de- 

 terminations of the height of, 

 458. 



Porphyries of America, 475. 



Porphyry of the Puy de D6me, 

 its peculiar character, 450. 



Portobello, hot springs of, 193. 



Pozzuoli, eruption from the solfa- 

 tara of, 423. 



Procida or Prochyta, 265. 



Proclus on earthquakes, 179. 



Pulu Batu, lava-sti-eams of, 382. 



Pumex Pompeianus, 430. 



Pumice not found at Jorullo, 319; 

 abundant in Lipari, 340; the 

 pumice quarries of Lactacuuga, 

 342 ; of Cotopaxi, 343 ; isolated 

 eruptions of, 344 ; found in 

 Madagascar, 384 ; and in the 

 island of Amsterdam, 387; Hum- 

 boldt's view of its formation, 

 483. 



Pumice eruption of the Eifel, 236. 



Punhamuidda, volcano of, 290. 



Pusambio, the river, acidified by 

 sulphur, 202. 



Pyrenees, highest summits of the, 

 230, 231. 



Pyriphlegethon, Plato's geognostic 

 myth, 35, 268. 



Quelpaert's island, a volcano, 376. 

 Quesaltenango, Volcan de, 277. 

 Quetelet on daily variations of 



temperature, 38. 

 Qaludiu. See Azufrol de Quindiu. 



Quito, observations on the older 

 rocks of the volcanic elevated 

 plains of, 444. 



Quito and New Granada, the 

 group of volcanoes of, 281. 



Rainier (or Regnier) Mount, an 

 active volcano, 418. 



Rains, regions of summer, autumn, 

 and winter, 188. 



Raking of mountain chains ex- 

 plained, 294. 



Rammelsberg's analysis of the 

 Chimborazo rock, 461. 



Ranco, volcano of, 290. 



Rapilli, 234. 



Raton Mountains, extinct volca- 

 noes of the, 413. 



Regnier, Mount, an active volcano, 

 418. 



Rehme, the Artesian well at, 36. 



Reich's experiments to determine 

 the density of the earth, 31; the 

 subject more lately investigated 

 by Airy, vii. 



Results of observation in the tel- 

 luric portion of the physical 

 description of the universe, 8. 



Revillagigedo, volcanic islands of, 

 281. 



Ribbed formation of the volcanoes 

 of the island of Java, 303 ; ana- 

 logous phenomena of the mantle 

 of the Sornma of Vesuvius, 

 305. 



Richer, observations on the pen- 

 dulum, by, 19. 



Rigaud, Professor, on the propor- 

 tion of water and terra firm a, 

 388. 



Riudjana, a volcano, its height, 

 881. 



Riobamba, terrible earthquake at, 

 167, 172, 173. 



Rio Vinagre, described, 202. 



Rock-debris, 331. 



Rocky Mountains, the chain de- 

 scribed, 411; traces of ancient 

 volcanic action, 414 ; parallel 

 coast ranges, still volcanic, 4 1 Jv 



