TRUE VOLCANOES. 367 



blackish-gray, and more trachytic than basaltic, lavas of the 

 summit abound in feldspar. The extraordinary fluidity of 

 the lavas of Mouna Loa, whether issuing from the summit 

 crater (Mokua-weo-weo) or from the sea of lava (on the east- 

 ern declivity of the volcano, at a height of only 3969 feet 

 above the sea), is testified by the glass threads, sometimes 

 smooth and sometimes crisped or curled, which are dispersed 

 by the wind all over the island. This hair glass, which is 

 likewise thrown out by the volcano of Bourbon, is called 

 Pele's hair by the Hawaiians, after the tutelary goddess of 

 the country. 



Dana has ably demonstrated that Mouna Loa is not the 

 central volcano of the Sandwich Islands, and that Kilauea is 

 not a solfatara.* The basin of Kilauea is 16,000 feet (about 

 2 geographical miles) across its long diameter, and 7460 feet 

 across its shorter one. The steaming, bubbling, and foaming 

 mass w r hich forms the true lava pool does not, however, under 

 ordinary circumstances, fill the whole of this cavity, but mere- 

 ly a space whose long diameter measures 14,000 feet and its 

 breadth 5000 feet. The descent to the edge of the crater is 

 graduated. This great phenomenon produces a wonderful 

 impression of silence and solemn repose. The approach of 

 an eruption is not here indicated by earthquakes or subterra- 

 nean noises, but merely by a sudden rising and falling of the 

 surface of the lava, sometimes to the extent of from 300 or 

 400 feet up to the complete filling of the whole basin. If, 

 disregarding the immense difference in size, we were to com- 

 pare the gigantic basin of Kilauea with the small side craters 

 (first described by Spallanzani) on the declivity of Stromboli, 

 at four fifths of the height of the mountain, the summit of 



the insurgents in the year 1789, an eruption of hot ashes, accompanied 

 by an earthquake, enveloped the surrounding country in the darkness 

 of night (p. 183). On the volcanic glass threads (the hair of the god- 

 dess Pelc, who, before she went to settle at Hawaii, inhabited the now 

 extinct volcano of Hale-a-Kala or the House of the Sun on the isl- 

 and of Maui) see p. 179 and 199-200. 



* Dana, p. 205. " The term Solfatara is wholly misapplied. A sol- 

 fatara is an area with streaming fissures and escaping sulphur vapors, 

 and without proper lava ejections ; while Kilauea is a vast crater with 

 extensive lava ejections and no sulphur, except that of the sulphur 

 banks, beyond what necessarily accompanies, as at Vesuvius, violent 

 volcanic action." The structural frame of Kilauea, the mass of the 

 great lava basin, consists also, not of beds of ashes or fragmentary 

 rocks, but of horizontal layers of lava, arranged like limestone. Dana, 

 p. 193. (Compare Strzelecki, Phys. Descr. of New South Wales, 1845, 

 p. 105-111.) 



