x 



24 



ETNA. 



[Ch. XXVI. 



approach of a fiery current, 2^ miles broad; when sud- 

 denly two small threads of liquid matter issuing from 



om the mam 



He 



a 



ran 



rapidly towards the hill, 

 escape when they saw the hill, which was 50 feet in height 

 . surrounded, and in a quarter of an hour melted down into the 



mass 



complete fasio 



immense 



rocky matter coming in contact with lava is of universal, or 

 even common occurrence. It probably happens when fresh 

 portions of incandescent matter come successively in contact 

 with fusible materials. In many of the dikes which intersect 

 the tuffs and lavas of Etna, there is scarcely any perceptible 

 alteration effected by heat on the edges of the horizontal 

 beds, in contact with the vertical and more crystalline mass. 

 On the site of Monpileri, one of the towns overflowed in the 

 great eruption above described, an excavation was made in 



labour the workmen reached, at the 

 depth of 35 feet, the gate of the principal church, where 

 there were three statues^ held in high veneration. One 

 of these, together Avith a bell, some money, and other articles, 

 were extracted in a good state of preservation from beneath 

 a great arch formed by the lava. It seems very extra- 

 ordinary that any works of art, not encased with tuff, like 

 those in Herculaneum, should have escaped fusion in hollow 

 spaces left open in this lava current, which was so hot at 

 Catania eight years after it had entered the town, that it was 

 impossible to hold the hand in some of the crevices. 



S'lihterranean caverns on Etna. — Mention was made of the 

 entrance of a lava stream into a subterranean grotto, whereby 

 the foundations of a hill were partly undermined. Sucb 



t> 



most 



on Etna, and may perhaps be caused by the sudden coii- 



eams 



by a fiery current. Great volumes of vapour thus produced 



may 



externally with a solid crust, and may cause the sides of 

 such passages as they harden to assume a very irregular 

 outline. Near Nicolosi, not far from Monti Eossi, one of 



mi _ » 



\ 



I 



CH' 



5; 



deep- 

 seen 



d 



va 



15 to 



y 



et e 



unkii' 



pos 



ed 



Tbec 



parts 



my 



fi: 



striki 

 oftb 



wlio 

 to Iii 

 as m 



islaiic 



TIk 



alread 



andd 

 ifliles , 

 a paiK 



n^oimt 

 Bove, 



visibl 



e 



111 



tlie 



J'eai-s 1 



til 



e 



ev 



a 



• 



