ave varied in intensity from time to time.

It has been observed that the violence of its eruptive force has a
certain dependence on the weather--being always most intense when the
barometer is lowest. From the position of the crater, it is possible to
ascend the mountain and look down upon it from above. Even when viewed
in this manner, it presents a very striking appearance. While there is
an uninterrupted continuance of small explosions, there is a frequent
succession of more violent eruptions, at intervals varying in length
from seven to fifteen minutes.

HOFFMAN AT STROMBOLI

Several eminent observers have approached quite close to the crater,
and examined it narrowly. One of these was M. Hoffman, who visited it in
1828.

This eminent geologist, while having his legs held by his companions,
stretched his head over the precipice, and, looking right down into the
mouth of one of the vents of the crater immediately under him, watched
the play of liquid lava within it. Its surface resembled molten silver,
and was constantly rising and falling at regular intervals. A bubble of
white vapor rose and escaped, with a decrepitating noise, at each ascent
of the lava--tossing up red-hot fragments of scoria, which continued
dancing up and down with a sort of rhythmic play upon the surface.
At intervals of fifteen minutes or so, there was a pause in these
movements. Then followed a loud report, while the ground trembled, and
there rose to the surface of the lava an immense bubble of vapor. This,
bursting with a crackling noise, threw out to the height of about 1200
feet large quantities of red-hot stones and scoriae, which, describing
parabolic curves, fell in a fiery, shower all around. After another
brief repose, the more moderate action was resumed as before.

Lipari, a neighboring volcano, was formerly more active than Stromboli,
though for centuries past it has been in a state of complete quiescence.
The Island of Volcano lies south of Lipari. Its crater was active before
the Christian era, and still emits sulphurous and other vapors. At
present its main office is to serve as a sulphur mine. Thus the peak
which gives title to all fire-breathing mountains has become a servant
to man. So are the mighty fallen!

CHAPTER XXIII.

Skaptar Jokull and Hecla, the Great Icelandic Volcanoes.

The far-northern island of Iceland, on the verge of the frozen Arctic
realm, is one of the most volcanic countries in the wor