29th
September, the earth sunk down about 14 feet in that place where the
volcanic orifice now appears, and there issued forth a small stream of
water, at first cold, and afterwards tepid. At noon, on the same day,
the earth began to swell up in the same spot where it had sunk down 14
feet, so as to form a hill. About this time fire issued forth, and gave
rise to the great gulf, "with such a force, noise, and shining light,
that I, who was standing in my garden, was seized with terror. Forty
minutes afterwards, although unwell, I got upon a neighboring height,
from which I saw all that took place, and by my troth it was a splendid
fire, that threw up for a long time much earth and many stones, which
fell back again all round the gulf, in a semicircle of from one to three
bow-shots in diameter, and, filling up part of the sea, formed a hill
nearly of the height of Monte Morello. Masses of earth and stones, as
large as an ox, were shot up from the fiery gulf into the air, to a
height which I estimate at a mile and a half. When they descended, some
were dry, others in a soft muddy state." He concludes by alluding again
to the sinking of the ground, and the elevation of it which followed,
and says that to him it was inconceivable how such a mass of stones and
ashes could have been poured forth from the gulf. He also refers to the
account which Porzio was to draw up for the Viceroy.

On comparing these four accounts, recorded by eye-witnesses, there
appears to be no real discrepancy between them. It seems clear that the
ground first sunk down 14 feet on the site of the future volcano, and
after having subsided it was again propelled upwards by the lava mingled
with steam and gases, which were about to burst forth. Jets of red-hot
lava, fragments of fractured rock, and occasionally mud composed of a
mixture of pumice, tuff, and sea-water, were hurled into the air. Some
of the blocks of stone were very large, leading us to infer that the
ground which sank and rose again was much shattered and torn to pieces
by the elastic vapors. The whole hill was not formed at once, but by an
intermittent action extending over a week or more. It seems that the
chasm opened between Tripergola and the baths in its suburbs, and that
the ejected materials fell and buried that small town. A considerable
part, however, of the hill was formed in less than twenty-four hours,
and in the same manner as on a smaller scale the mud cones of the air
volca