INDEX. 



495 



Oeynhausen, temperature of the 



salt spring at, 36. 

 Oisans, natural amphitheatre of, 



its vast extent, 231. 

 Oligoclase, 471. 



Olot, extinct volcanoes of, 433. 

 Olympus, Mount, in America, 



418. 



Omato, Volcan de, 286. 

 Ometepec, an active volcano, 273. 

 Orinoco, high temperature of its 



waters at certain seasons, 186. 

 Orizaba, a volcano, measurement 



of the peak of, 251 ; lava field 



of, 3-24. 

 Oron, fresh-water lake of, seals 



found in the, 437. 

 Orosi, the volcano, 273. 

 Orthoclase, 480. 

 Osomo, volcano of, 290. 

 Overweg's researches on volcanic 



phenomena in Africa, 355. 

 Ovid, volcanic phenomena clearly 



described by, 229. 

 Owhyhee. See Haivaii. 



Pacaya, eruptions of, 276. 



Pacific Ocean, the term "Grand 

 Ocean," improperly applied to 

 the, 404; comparatively small 

 number of active volcanoes, 

 388 , grouping of its islands by 

 Dana, 390. See also South 

 Pacific Ocean, South Sea. 



Panguipulli, Volcan de, 290. 



Papagayos, remarkable storms so 

 called, 271. 



Paramos, their elevation and vege- 

 tation, 294. 



Paramagnetism exhibited by oxy- 

 gen gas, 49 ; importance of the 

 discovery, 78, 82, 99. 



Parasitic craters of the Moon, 

 449. 



Parinacota, volcano of, 287. 



Passuchoa, the extinct volcano of, 

 337. 



Patricius, the bishop, his theory of 

 central heat, 196. 



Paul, St., volcanic island of, 384. 



Pele's hair, volcanic glass so called, 

 392. 



Pelileo, eruption of the Maya of, 

 172,216. 



Pendulum, vibrations of the, ap- 

 plied to determine the figure of 

 the earth, 1 9 ; Sabine's expedi- 

 tion, 22 ; other observers, 23 ; 

 the form of the earth not ex- 

 actly determinable by such 

 means, 25 ; Airy's experiments 

 at Harton, vii. 



Pentland, his discovery of lava- 

 streams in the eastern chain of 

 the Andes, 295. 



Perlite, 344. 



Pertusa, hot springs of, 196. 



Peru and Bolivia, series of voles- 

 noes of, 292. 



Peshan, volcano of, 356, 434. 



Peteroa, volcano of, 289. 



Peterman's notices from Overweg, 

 of volcanic phenomena in Africa, 

 355. 



Phaselis, flame of the Chimgera, 

 near, 212. 



Philippines, volcanoes of the, 243. 



Phlegreean fields, ancient descrip- 

 tions of the, 428. 



Pic de Xethou, the highest sum- 

 mit of the Pyrenees, 230. 



Pic of Timor, formerly an ever- 

 active volcano, 382. 



Pichincha, remarkable form of, 

 241 ; ascent of, by Humboldt, 

 242 ; visited by Wisse, 242 ; its 

 height, 250. 



Pichu-Pichu, Volcaii de, 286. 



Pico, the volcano, 247 ; eruptions 

 of other volcanoes in the Azores 

 apparently dependant on, 351. 



Piedmont, trembling of the earth 

 in, 183. 



Pill a, on the leucite-crystals of 

 Kocca Monfina, 466. 



Pisoje, basalt-like columns of, 

 456. 



Pithecusse, Bokh on the, 266. 



Pitt, Mo\mt, in America, 417. 



Plato, on the Pyriphlegethon, 35, 



