"I T is not late yet, Uncle," said Jules; "you ought to tell us about those terrible mountains, those volcanoes that the showers of ashes come from."
At the word "volcano," Emile, who was already asleep, rubbed his eyes and became all attention. He too wanted to hear the great story. As usual, their uncle yielded to their entreaties.
"A volcano is a mountain that throws up smoke, calcined
"An eruption is generally announced beforehand by a column of smoke that fills the orifice of the crater and rises vertically, when the air is calm, to nearly a mile in height. At this elevation it spreads out in a sort of blanket that intercepts the sun's rays. Some days before the eruption the column of smoke sinks down on the volcano, covering it with a big black cloud. Then the earth begins to tremble around Vesuvius; rumbling detonations under the ground are heard, louder and louder each moment, soon exceeding in intensity the most violent claps of thunder. You would think you heard the cannonades of a numerous artillery detonating ceaselessly in the mountain's sides.
"All at once a sheaf of fire bursts from the crater to the
height of 2000 or 3000 meters. The cloud that is floating
over the volcano is illumined by the redness of the fire;
the sky seems inflamed. Millions of sparks dart out like
lightning to the top of the blazing sheaf, describe great
arcs, leaving on their way dazzling trails, and fall in a
shower of fire on the slopes of the volcano. These sparks,
so small from a distance, are incandescent masses of stone,
sometimes several meters in dimension, and of a sufficient
momentum to crush the most solid buildings in their fall.
"It is both terrible and beautiful," said Jules. "Oh! how I should like to see an eruption, but far off, of course."
"And the people who are on the mountain?" questioned Emile.
"'They are careful not to go on the mountain at that time;
they might lose their lives, suffocated by the smoke or
crushed by the shower of
"Meantime, from the depths of the mountain, through the
volcanic chimney, ascends a flux of melted mineral
substance, or lava, which pours out into the crater and
forms a lake of fire as dazzling as the sun. Spectators who,
from the plain, anxiously follow the progress of the
eruption, are warned of the coming of the
"The flow of lava comes to an end, sooner or later. Then subterranean vapors, freed from the enormous pressure of the fluid mass, escape with more violence than ever, carrying with them whirlwinds of fine dust that floats in sinister clouds and sinks down on the neighboring plain, or is even carried by the winds to a distance of hundreds of leagues. Finally, the terrible mountain calms down, and peace is restored for an indefinite time."
"If there are towns near the volcanoes, cannot those streams of fire reach them? Cannot those clouds of ashes bury them?" asked Jules.
"Unfortunately all that is possible and has happened. I will
tell you about it