30 



ETNA. 



[Ch. XXVI. 



formed together with b at the base of the great precipice at 

 the head of the Val del Bove was about 500 feet high on 

 its eastern side at the end of 16 days. So great was the 



of fire. 



Lolten matter 

 ; Gemmellaro 

 September ii 



a 



before mentioned. In its descent over the precipice it 



sounded 

 broken. 



metallic and glassy substances were bein 



streams 



November 



2 miles 



and .6 



long. They continued to issue with some intermissions for 

 more than nine months until May 1853. The depth of 

 sinerle streams was from 8 to 16 feet, but when piled ovf^v 



Fig. 83. 



The two cones formed in the Val del Bove by the eruption of 1852. 



A, Lower part of Griannicola Grrande. 

 b. Upper or western cone. 



c. Lower cone called Centenario. 



d. Commencement of current of lava of 1852. 



one another they were from 30 to 50 feet thick, and at one 

 point near the Portella or lower entrance of the valley of 



seemed 



150 feet. 



have attained a thickness of 



An unusual event, and one of no small geological interest, 

 occurred some weeks after May 27th, when to all appearance 

 the flowing of lava had entirely ceased, and when all tlie 

 currents had become encrusted over with so firm a covering 

 of scoriae that the inhabitants could walk upon them with 

 safety. Within a certain area six or seven hundred yards in 

 diameter, and situated between Zafarana and Ballo, all tlie 

 fruit-trees and vines w^ere struck dead as if by lightning. 

 The ground exhaled no hot gases,and the vegetation did 

 not suffer in the space intervening between the parched-np 



and the recent lava, which was only a few hundred 

 yards distant. Dr. Giuseppe Gemmellaro has suggested, as 

 the most natural explanation of the phenomenon, that the 

 lava had gradually made its way through underground pas- 



area 



r 



Ci' 



lS 



bore 



a 



J 



tlie 



lllO 



tiiiies 



fuse 



di 



pressui 

 times ■ 



legist V 

 clue to 



8 



k 



r 



\ . 





^ 



9 



(, 



e. 



Tnl) 

 out col 

 .eiallr ; 



a 



into lo 



tlie bot 



It 



seen 



•Jesolat, 

 Pi'oduct 

 Pictm 



wa 



a 



^^^^k St 



^^^§' any 



