Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1875-12-29
vESUVIUS.

~
COmm0tiOns Of the Burning aOun-
taln-rhe .'aetsmOgraPh, or Earth
Naples correspondence American (Paris)
Register.lO
Probably before this letter reaches the
Register you will have already inserted
in your eoIUDns the notice from Prof
Palmieri, who watches high up in the
observatory on the slopes Of Vesuvius
that the old volcano is showing signs Of
an eruption. The daily Pungolo of
Naples is the ordinary medium of the
Professor announcements Of the threat.
ening OF the historic land, for all that,
prehistoric) fire mountain that rears its
graceful form above the Bay Of Naples.
Before the Bourbon regime had ceased
observations were established in the
meteorological observatory referred to,
with the end in view Of recording the
phenomena connected with Vesuvius,
and, If possible, to give warning Of ap-
preaching eruptions. This has been par.
TALLY successful, for that most frequently
recurring phenomenon in connection
with volcanoes-the earthquakes i'm
mediately detected by an instrument
called
THE sEIsMoGRAPH
Earthquake writer); the slightest shock
is readily indicated by the sensitive
mechanism. This instrument is the in
vention Of Palmieri, who is professor
in the University of Naples, and one of
the most eminent physicists living. No
proper description could be given with
out engravings Of the seismograph, by
which the Professor feels the puIsations
of earthquakes; but Robert Mallet, the
first authority on earthquakes and vol
canoes, states the general principle to
be one =" in which wave movements are
indicated by the displacement, relative
or absolute, of columns Of mercury in
glass tubes. II is a self-recording in
strument, composed of two distinct por.
for record of horizontal, or
rather what ara called uudulatofy
shocks; the other for vertical shocks"
Now, while the seismograph has been
most successful in recording the earth
quake movements, as foreteller of
eruptions it cannot be said to be perfectly
reliable when taken alone; but il its re-
cordings are taken in conjunction with
careful observations of the igneous and
other indications OF Vesuvius an erup-
ton can pretty surely be foretold. Such
a conjunction has just occurred, which
has caused the communication to the
Pungolo, and we learn from Professor
Palmieri that Vesuvius gives unmistaka-
Bile symptoms OF an approaching erup-
ton.
THE CRATER
formed by the terrible eruption Of 1872
has been falling in on the southeast, or,
to use the exact language of the Profess
sor, has been becoming bottomless,
with emanations Of black smoke. The
instruments at the observatory are
slightly agitsted. There is no telling
when igneous results will follow these
indications. But in the month of De.
cember, 1854, similar phenomenon
manifested itself in the crater, and the
eccentric eruption, with copious floods
of lava, took place in May, 1855" /"
THE PROFESSOR DOES NOT PREDICT
with absolute certainty when the next
eruption will take place. Indeed, he
cannot, for we must remember that
Monte Nuovo, in the sixteenth century
was thrown up between Pozzuolo (Pu-
teolil and Baia in single night; and, as
Mallet has well observed, "a small fusi.
lade may 90 on for months, and yet,
without an hours notice by any pre-
monitory sign, may waken up with
roar, and darken the air with ashes and
lapilli, such as those which overwhelmed
Pompeii, One eruption may blow forth
little but dust and ashes (so-called). and
another may pour out rivers Of lava and
little else.
The ERUPTION OF 1850
took place in February of that year,
when l happened to be travelling in
Southern Italy. | was just finishing my
student days, aud my mind was very
open to impressions. Sihes that time /
have gazed not only upon Sromboli and
Etna, but upon the loitiest volcanoes of
South America; but for the display Of
awful power---of awful sublimity and
after scene impressed me
more soleLlnly and deeply than this
Of Mount Vesuvius, when the
mountain, ceasing to ejeco volcanic mat.
tef from its ordinary channel, opened
far below two craters on the very side
the southeastern-which is now giving
indications The new crater
in 1850 shot forth three streams of lava.
The most considerable was that which
took the direction of Bosoo Reale, viii
lage just above Pompeii. Indeed, the
lava, If it had flowed little more than
a mile further, would have utterly de.
stroyed what the ashes left Of Pompeii
1900 years ago. This lava stream, in
rushing toward the village Of Bosoo
Reale, marched through wood Of oak,
lick and ash As it inclosed the trees
the heat engendered steam in the eavi.
ties OF the roots aud trunks, the loud
detonAtions of bursting trees and the
immediate blaze which followed formed
q pyrotechnic display of the most bril-.
liant character.
THE NUMBER OF RECORDED ERUPTIoNs
from the first century to the seventeenth
inclusive was nineteen, little more
than the average of one per CEN
tury. During the eighteenth century
there were twenty-three, one on the aver.
age Of about four and half years.
Up to the present time in this century
there have occurred twenty-five erup-
tions or an average of one in every three
years. AS the last took place in April,
1872, we may confidently soon look for
another.
An Ant shop in Paris.