The first are active volcanoes, around which there may be established
many secondary active mouths of eruption, always in connection with some
principal crater. The second are disposed like the chimneys of furnaces,
along fissures extending over considerable distances. Twenty, thirty,
and even a greater number of volcanic cones may rise above one such rent
in the earth’s crust, the direction of which will be indicated by their
linear course. The Peak of Teneriffe is an instance of a central
volcano; the long rampart-like chain of the Andes, presents, from the
south of Chili to the north-west coast of America, one of the grandest
instances of a continental volcanic chain; the remarkable range of
volcanoes in the province of Quito belong to the latter class. Darwin
relates that on the 19th of March, 1835, the attention of a sentry was
called to something like a large star which gradually increased in size
till about three o’clock, when it presented a very magnificent
spectacle. “By the aid of a glass, dark objects, in constant succession,
were seen in the midst of a great glare of red light, to be thrown up
and to fall down. The light was sufficient to cast on the water a long
bright reflection--it was the volcano of Osorno in action.” Mr. Darwin
was afterwards assured that Aconcagua, in Chili, 480 miles to the north,
was in action on the same night, and that the great eruption of
Coseguina (2,700 miles north of Aconcagua), accompanied by an earthquake
felt over 1,000 miles, also occurred within six hours of this same time;
and yet Coseguina had been dormant for six-and-twenty years, and
Aconcagua most rarely shows any signs of action.[25] It is also stated
by Professor Dove that in the year 1835 the ashes discharged from the
mountain of Coseguina were carried 700 miles, and that the roaring noise
of the eruption was heard at San Salvador, a distance of 1,000 miles.
[25] Darwin’s “Journal,” p. 291, 2nd edition.
In the sea the _series_ of volcanoes show themselves in groups of
islands disposed in longitudinal series.
Among these may be ranged the volcanic series of Sunda, which, according
to the accounts of the matter ejected and the violence of the eruptions,
seem to be among the most remarkable on the globe; the series of the
Moluccas and of the Philippines; those of Japan; of the Marianne
Islands; of Chili; of the double series of volcanic summits near Quito,
those of the Antilles, Guatemala, and Mexico.
Among the central, or isolated volcanoes, we may class those of the
Lipari Islands, which have _Stromboli_, in permanent activity, for
their centre; _Etna_, _Vesuvius_, the volcanoes of the _Azores_, of the
_Canaries_, of the _Cape de Verde_, of the _Galapagos_ Islands, the
_Sandwich_ Islands, the _Marquesas_, the _Society_ Islands, the
_Friendly_ Islands, _Bourbon_, and, finally, _Ararat_.
[Illustration: Fig. 10.--Existing crater of Vesuvius.]
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