nal
forces which was presently to follow.

(_k._) _Eruption of 1872._--The grand eruption of 1872, of which a
detailed account is given by Professor Palmieri,[10] commenced with a
slight discharge of incandescent projectiles from the crater; and on the
13th January an aperture appeared on the upper edge of the cone from
which at first a little lava issued forth, followed by the uprising of a
cone which threw out projectiles accompanied by smoke, whilst the
central crater continued to detonate more loudly and frequently. This
little cone ultimately increased in size, until in April it filled the
whole crater and rose four or five metres above the brim. At this time
abundant lavas poured down from the base of the cone into the Atria del
Cavallo, thence turned into the Fossa della Vetraria in the direction of
the Observatory and towards the Crocella, where they accumulated to
such an extent as to cover the hillside for a distance of about 300
metres; then turning below the Canteroni, formed a hillock without
spreading much farther.

In October another small crater was formed by the falling in of the
lava, which after a few days gave vent to smoke and several jets of
lava; and towards the end of October the detonations increased, the
smoke from the central crater issued forth more densely mixed with
ashes, and the seismographical apparatus was much disturbed. On the 3rd
and 4th November copious and splendid lava-streams coursed down the
principal cone on its western side, but were soon exhausted; and in the
beginning of 1872 the little cone, regaining vigour, began to discharge
lava from the summit instead of the base as heretofore.

In the month of March 1873, with the full moon, the cone opened on the
north-west side--the cleavage being indicated by a line of
fumaroles--and lava issued from the base and poured down into the Atria
as far as the precipices of Monte di Somma. On the 23rd April (another
full moon) the activity of the craters increased, and on the evening of
the 24th splendid lava-streams descended the cone in various directions,
attracting on the same night the visits of a great many strangers. A
lamentable event followed on the 26th. A party of visitors, accompanied
by inexperienced guides, and contrary to the advice of Professor
Palmieri, insisted on ascending to the place from which the lava issued.
At half-past three on the morning of the 26th they were in the Atria del
Cavallo, when the Vesuvian cone