These fiery currents ran
through the snow to a distance of three miles, melting it as they
flowed. The consequence was, that a tremendous torrent of water rushed
down the sides of the mountain, carrying with it vast quantities of
sand, volcanic cinders and blocks of lava, with which it overspread the
flanks of the mountain and the plains beneath, which it devastated in
its course.
The volume of water was estimated at 16,000,000 cubic feet, it forming
a channel two miles broad and in some places thirty-four feet deep,
and flowing at the rate of two-thirds of a mile in a minute. All the
winter's snow on the mountain could not have yielded such a flood,
and Lyell considered that it melted older layers of ice which had been
preserved under a covering of volcanic dust.
ETNA IN 1819
Another great eruption took place in 1819, which presented some
peculiarities. Near the point whence the highest stream of lava
issued in 1811, there were opened three large mouths, which, with loud
explosions, threw up hot cinders and sand, illuminated by a strong glare
from beneath. Shortly afterwards there was opened, a little lower down,
another mouth, from which a similar eruption took place; and still
farther down there soon appeared a fifth, whence there flowed a torrent
of lava which rapidly spread itself over the Val del Bove. During the
first forty-eight hours it flowed nearly four miles, when it received a
great accession. The three original mouths became united into one large
crater, from which, as well as from the other two mouths below, there
poured forth a vastly augmented torrent of lava, which rushed with great
impetuosity down the same valley.
Pages:
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315