Sir C. Lyell on the Conical Form of Volcanoes. 225 
Etna been melted instantaneously, they could not have furnished 
enough water for the deluge. He, therefore, concluded that 
the water was vomited forth from the summit crater itself. Sir 
ople o a, he n 
ner in which the frontal wall of lava, 80 feet high, and inclined 
at an angle of 37°, had crept slowly over green pastures and 
1852-53 in the scenery of the Val del Boye, and in that of the 
lower Valley of Calanna, in the interval since 1828, when the 
both in a northeast stance 
of six miles, with a breadth in each case of two miles, and having 
been piled u the other in some places (as at the Por- 
pl td one over the o ( ae loo ao? hdl Vani 
: ‘on the surface of this nev 
field are from 20 to 70 feet high; and there is now a 
