t outbreak of especial violence took place in 1779, when what
seemed to the eye a column of fire ascended two miles high, while cinder
fragments fell far and wide, destroying the hopes of harvest throughout
a wide district. They fell in abundance thirty miles distant, and the
dust of the explosion was carried a hundred miles away.

In 1793 the crater became active again, and in 1794 after a period of
short tranquillity or comparative inaction, the mountain again became
agitated, and one of the most formidable eruptions known in the history
of Vesuvius began. It was in some respects unlike many others, being
somewhat peculiar as to the place of its outburst, the temperature of
the lava, and the course of the current. Breislak, an Italian geologist,
observed the characteristic phenomena with the eye of science, and his
account supplies many interesting facts.

BREISLAK ON THE ERUPTION OF 1794

Breislak remarked certain changes in the character of the earth's
motions during this six hours' eruption, which led him to some
particular conjecture of the cause. At the beginning the trembling was
continual, and accompanied by a hollow noise, similar to that occasioned
by a river falling into a subterranean cavern. The lava, at the time
of its being disgorged, from the impetuous and uninterrupted manner in
which it was ejected, causing it to strike violently against the walls
of the vent, occasioned a continual oscillation of the mountain. Toward
the middle of the night this vibratory motion ceased, and was succeeded
by distant shocks. The fluid mass, diminished in quantity, now pressed
less violently against the walls of the aperture, and no longer issued
in a continual and gushing stream, but only at intervals, when the
interior fermentation elevated the boiling matter above the mouth. About
4 A. M. the shocks began to be less numerous, and the intervals between
them rendered their force and duration more perceptible.

During this tremendous eruption at the base of the Vesuvian cone, and
the fearful earthquakes which accompanied it, the summit was tranquil.
The sky was serene, the stars were brilliant, and only over Vesuvius
hung a thick, dark smoke-cloud, lighted up into an auroral arch by the
glare of a stream of fire more than two miles long, and more than a
quarter of a mile broad. The sea was calm, and reflected the red glare;
while from the source of the lava came continual jets of uprushing
incandescent stones. Ne