226 = Sir C. Lyell on the Conical Form of Valcanoes. 
One branch of this lava of 1852 cascaded over a precipitous 
declivity 500 feet high, at the head of the Valley of Calanna, and 
consolidated at angles of 35°, 45°, and even 49°. The scoriace- 
ous crust having been partially washed off, the surface of a con- 
tinuous crystalline and stony mass is exposed to view, onl 
1819, which passed down the same steep cliff, and which has at 
some points a dip of more than 40°. ; 
he author continues with facts and reasonings similar to 
what is published in his paper of last year (this Journal, vol. 
XXvi, p. 214)]: 
In conclusion, the lecturer gave a brief sketch of the series of 
geological events which he supposed to have occurred on the site 
of Etna since the time of the earliest eruptions, events which may 
have required thousands of centuries for their development. 
The first eruptions are believed to have been submarine, occur- 
ring probably in a bay of the sea, which was gradually converted 
into land by the outpouring of lava and scoria, as well as by 
a slow and simultaneous upheaval of the whole territory. e 
b salts, and other igneous products of the Cyclopean Islands 
were formed contemporaneously in the same sea, the molluscous 
formed at successive heights. The remains of elephants, and 
are found in these old 
uffs 
first the cone of Trifoglietto, and probably the lower part of the 
o 
cone of Mongibello, was built up; still later the cone last-men 
tion coming the sole centre of activity, overwhelmed the 
: vari forma- 
tions, including the truncation of its summit, and the formation 
of the V; 
