s been numerous--more
especially during the intervals when Vesuvius was inactive--there being
a sort of alternation between the periods of great activity of the two
mountains; although there are not a few instances of their having been
both in action at the same time.

SIMILARITY IN ETNA'S ERUPTIONS

There is a great similarity in the character of the eruptions of Etna.
Earthquakes presage the outburst, loud explosions follow, rifts and
bocche del fuoco open in the sides of the mountain; smoke, sand, ashes
and scoriae are discharged, the action localizes itself in one or more
craters, cinders are thrown up and accumulate around the crater and
cone, ultimately lava rises and frequently breaks down one side of the
cone where the resistance is least; then the eruption is at an end.

Smyth says: "The symptoms which precede an eruption are generally
irregular clouds of smoke, ferilli or volcanic lightnings, hollow
intonations and local earthquakes that often alarm the surrounding
country as far as Messina, and have given the whole province the name
of Val Demone, as being the abode of infernal spirits. These agitations
increase until the vast cauldron becomes surcharged with the fused
minerals, when, if the convulsion is not sufficiently powerful to force
them from the great crater (which, from its great altitude and the
weight of the candent matter, requires an uncommon effort), they explode
through that part of the side which offers the least resistance with a
grand and terrific effect, throwing red-hot stones and flakes of fire to
an incredible height, and spreading ignited cinders and ashes in every
direction."

After the eruption of ashes, lava frequently follows, sometimes rising
to the top of the cone of cinders, at others disrupting it on the least
resisting side. When the lava has reached the base of the cone it begins
to flow down the mountain, and, being then in a very fluid state, it
moves with great velocity. As it cools, the sides and surface begin to
harden, its velocity decreases, and after several days it moves only
a few yards an hour. The internal portions, however, part slowly with
their heat, and months after the eruption clouds of steam arise from the
black and externally cold lava-beds after rain; which, having penetrated
through the cracks, has found its way to the heated mass within.

THE ERUPTION OF 1669

The most memorable of the eruptions of Etna was that which elevated the
double c