The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1866-10-27
The Inactive Oraters of VesuVlus.
BY PROFESSOR D. T, ANsrED, F. R s.


There exist around Naples so many volcanic
cones, and these are in conditions 80 different in
some respects, and so similar in Others that
they are objects of very special interest to the
geoloaioal traveller. But they are hardly less
interesting to those who have no special interest
in geology, for most of them may be brought
into direct association with the historical events
for which this part OF Italy is SO remarkable.
The written history Of the eruptions with which
they are connected hardly commences much
before the Christian era but after this they mark,
by some corresponding event, almost every GEN.
tury as Il passed away Some of them, no
doubt, are very much older than any recorded
historical events for under other appearances
perhaps these, as we'll as the old cones and
craters of vesuvius itself, have seen many
human revolutions, even il they have not ante
dated the human race. The whole country,
however, is full Of interest. We turn from a
modern lava current to look at the steps of old
lava on which st. Paul trod when landing at
Puteoli, on his way to Rome. After examining
craters long since extinct, and serving as the
foundation of many an early pagan legend, we
find close by the grand substructions of an am.
phitheasre, in which old paganism, still ram-
pant though almost in its dying agonies, at
religion, by forcing its advocates to fight with
each other, or with wild beasts better taken
care of than the human victims. There are
hundreds of such points, where the interests OF
science and history are so mixed together that
it Is difficult to separate them, or forget either
one or the other.
All the important cTaters near Naples not
actually forming part OF vesuvius ITSELF are on
The western side OF the city, in the district of
the Phlegrean fields, and the islands beyond.
The nearest 10 Naples, one OF the largest and
one OF the most remarkable, il that In which is
placed the celebrated monastery of the Canal
doni. Within this is the lake of Agnano, q
newer cone and crater, where is the well-known
GroHo del cane. Beyond is the grand crater
of the Astroni, and next it the familiar Solfatara
These are succeeded by the smaller cones of the
Maranisi and the Cieliano The Monte Barbara,
with its Campiolione, a large and deep
crater, next follows, and near it is the Monte
Muovo. Beyond this again is the Lake
Avernus, while the Monte Grillo and Monte
hosso near Cum@, are Immediately
adjacent: The islands of Nisita, Procida, and
Ischia also afford ample proof of the extension
OF the line of volcanic action in very recent
times TO considerab e distance beyond its pre-.
sent apparent limits, N1slta being indeed very
perfect crater. The whole coast abounds with
all kinds of indications OF subdued volcanic
activity. These consist of eruptions of hot air
ana steam, numerous thermal springs, cele-
Drated In ancient as well as modern times,
gaseous emanations, and occasional sulphur
springs. The ground has been and still is sub
Ject 10 elevation and depression to an extent
suflclent to affect seriously buildings near the
shore. The celebrated temple of Jupiter Serapis.
at Pozzuoh affords ample proof OF these move
ments, and the whole coast has evidently under
gone great change in comparatively recent
times. Ii is doubtless still moving.
:, The lake OF Agnano is a good introduction to
tne Phenomena usually presented by these
sllent volcanoes, and it is very accessible
1rom 1 Naples. 1t is surrounded by hills en-
fnfa nah
down by the weather, and these walls Of ash
form large crater, depressed to about the level
OF the sea; IT is doubtless DID, though newer than
other tutaceous hills round Naples. In the
Roman times its shores seem to have been
already covered with vegetation, and its bed
was not, as it is now, filed with water. 1t was.
mains OF masonry and brickwork on a large |
scale are still to be seen at the bottom of the |
HILL near the edges OF the lake, and on the sides
of the crater. There are also marks of tunnels,
probably like that of Posllipo, which have led
into this crater to avoid the trouble of mount
ing and descending the HILL These are now
avoided by an open cutting, which exhibits the
structure OF the cone to the level of the water.
As far as this point the whole is tufa and there
seems to be no lava. The lake of Agnano is a
delicious specimen of characteristic volcanic
landscape. The volcanic ash has been very
easily decomposed, and readily converted into
good soil, and thus the whole of the inclosing
hills are richly clothed with vegetation,
There are many small but picturesque
villas and pretty gardens around it, The outer
circumference OF the inclosing hills is nearly
three miles, showing large crater, aud the
greater part OF the bottom Is now occupied by
water. The inclosng walls are less regular than
most OF the detached cones of any size, and are
comparatively low and open towards the north.
The flat, covered by water, is very unhealthy,
and measures are in progress to drain the lake,
1t may gain in salubrity what is lost in pictu-
rescue beauty. On the southeast side of the lake
rs a building with the remains of old stufe
or chambers where hot vapor issues at q
very nigh temperature, and Immediately be-
hind this are very extensive runs, probably
of Roman baths. The hot vapor issues at a
temperature of $50 deg. Fahrenheit, and is sui
is the well-known Grouo del Cane, where is an
issue of carbonic acid gas and hot air with
steam. The heavy carbonic acid gas, the choke
damp OF mines and wells, remains on the floor
of the small cavern in quantity sufficient to
asphy kate dogs or other small animals forced to
remain near the ground in this atmosphere.
The experiment might be tried with equal sue
cess, and greater convenience, in a brewers vat
These emanations OF g rs are, however, interest
ing, as proving the existence of subdued and
partial volcanic activity in this spot, which has
apparently remained in the same place, and to
the same extent, for the last two thousand years
III the visitor desires to satisfy himself of the
state OF the case without sitting the dog let
HIM dip his hat into the gas at the bottom oil the
cavern, and approach it 10 his mouth to drink
or breathe the gas.
Beyond the lake of Agnano to the west is
a valley intervening between the old cone of
Agnano and that of the Solfatara. In this val
ley, and just under the walls OF the cone of the
Astroni, which rises Immediately to the north,
are the hot stufe or vapor baths, OF the Piscia-
relli, prod uced by fumeroles in the rocks form
ing the back OF the crater of the Solfatara.
The whole of the lava OF the hills on the east of
the Solfatara crater will be found converted
into CHINA clay. The ground Is covered with