nearly perpendicular walls, broken in their continuity, every here
and there, by large projecting dykes, formed by the injection of
more recent lavas into fissures rent in those which had previously
become consolidated. Below the perpendicular walls is a rapid
slope, composed of fine ashes or sand, descending to the floor of
the crater, which is, for the most part, nearly flat. It is much
rent by fissures, which during the night are seen to glow with a
ruddy glare, emanating from the hot materials beneath, and giving
to the floor the appearance of being overspread with a fiery
tissue, like a spider's web. From the bottom there usually rise one
or two small craters of eruption, whence continually issue
sulphurous fumes, and which, at pretty regular intervals, discharge
showers of stones heated to whiteness.

The exterior of the cone is composed entirely of loose cinders,
ashes, and stones, so that the ascent is very laborious. The region
of the mountain beneath the cone presents no difficulties, and that
part of the ascent may be performed on donkeys or mules. The view
from the top is magnificent. The contrast between the desolate
aspect of the interior of the crater, and the smiling prospect
which may be seen from its edge, has been well compared to looking
out of Tartarus into Paradise.

Near Puzzuoli, in the Bay of Baiae, and not far from Monte Nuovo,
stand the ruins of the Temple of Serapis, so interesting to
geologists. These remains, consisting chiefly of the shafts of
three marble columns, still erect, though with a slight inclination
sea-ward, afford distinct proofs, confirmed by other phenomena in
the neighbourhood, that, since the beginning of the Christian era,
the level of the coast in relation to that of the sea has changed