Page:Popular Science Monthly Volume 1.djvu/240

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230
THE POPULAR SCIENCE MONTHLY.

have referred to the valley or ravine between the two mountains, the first descent to which on the side of Vesuvius is a sheer precipice. A great stream of lava, about 200 feet in width, issuing from the crater, took the direction of this ravine, and on arriving at the edge of the precipice fell heavily over it, forming a magnificent fiery cascade about 1,000 feet in height. On reaching the valley beneath, it wended its way through the woods, consuming the trees in its course, and destroying several villages through which it flowed. A grander sight than this cascade of fire must have presented, it would be difficult for the human mind to imagine.

Monnier says that, "since 1850, springs of lava have opened near the base of the cone in the ravine which separates the two mountains; they are seen springing from the lava much as the water of rivers flows from a glacier. In 1855 and 1858 it rolled slowly through the ravine like the Thames in flames. To be really startling, the lava must be seen, not from above, but coming directly toward the spectator, as I saw it in 1855. Then it was no longer a river, but a burning, moving rampart. This wall was at least a mile wide and 20 feet high. It came slowly, irresistibly, covering the ground, burning the trees and houses; you could walk backward before it as a captain does before his company.

"The lava, as it issues from the crater of Vesuvius, is perfectly liquid, and glows with an intense white brilliancy, like that of molten silver; but, as it descends, it begins to cool at the top, and a quantity of broken slag is formed on the surface of the stream, becoming ere long a continuous coating. The speed of the current, very rapid at first, gradually slackens, until, on the level at some distance from the mountain, its progress is scarcely perceptible."

Vesuvius is much more active in modern times than in ancient; several grand eruptions having taken place within the present generation. The recent convulsion has been marked by the usual impressive features, but comparisons with former eruptions must be accepted with hesitation, for, where the imagination is so powerfully affected, and the data are so uncertain, the judgment may be much at fault. The following description of the present display was telegraphed from Naples, April 29th:

"The view of Mount Vesuvius from this city is now the grandest that has been witnessed since the year 1631. Many persons have taken advantage of the panic among the people of the towns which were threatened with destruction, to take whatever goods they could find, and the government has been compelled to order troops to those places to prevent the stealing of abandoned property. In this city the Bourse has closed, and business is almost entirely suspended. The people use umbrellas to protect themselves from the falling ashes.

"A sound as of thunder accompanies the discharges. The wind was blowing in this direction this morning, carrying dense clouds of