“Of course not; and yet whole populations have their hearts frozen with fear at the inoffensive fall of a whirlwind of pollen or red dust. They believe themselves visited with plagues, precursors of the end of the world. Ignorance is a pitiful thing, my dear children, and knowledge is a fine thing, even if it only served to deliver us from stupid terrors.”
“In future,” said Jules, stoutly, “it can rain sulphur or blood; if any one is afraid, it will not be I.”
“There can also fall from the sky, with or without rain, various mineral substances, such as sand, for example, or powdered chalk, or dust from the roads. There is even mention of showers of small animals, caterpillars, insects, and very young toads. The marvelous feature of these rains disappears if one considers that a violent blast of wind can carry with it all light substances encountered in its course, and can transport them long distances before letting them fall again.
“At other times a rain of insects is due to something else besides transportation by the wind. Some kinds of grasshoppers, for example, gather together in immense swarms to go to another district when nutriment fails them. The emigrating band flies, as at a given signal, and passes through the air in the form of a great cloud that intercepts the daylight. The migration continues for days at a time, so numerous is the host. Then the voracious swarm alights, like a living storm, on the vegetation of some distant province. In a few hours grass, leaves of trees, grain, prairies—everything is browsed. The soil, as if ravaged by fire, hasn’t a blade of grass left. Sometimes the people of Algeria die of hunger. The grasshopper has devoured their harvests.
“Volcanoes cause cinder-showers. Volcanic ashes is the name given to the calcined dust thrown up to a great height by volcanoes at the moment of their eruption. These powdered substances form enormous clouds, which produce in the daytime a darkness like that of the darkest nights, and which, falling to earth at a greater or less distance, stifle animals and plants under their showers of dust.”
CHAPTER XLV
VOLCANOES
“IT 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 dust, red-hot stones, and melted matter called lava. The summit is hollowed out in a great excavation having the shape of a funnel, sometimes several leagues in circumference. That is what we call the crater. The bottom of the crater communicates with a tortuous conduit or chimney too deep to estimate. The principal volcanoes of Europe are: Vesuvius, near Naples; Etna in Sicily; Hecla in Iceland. Most of the time a volcano is either in repose or throwing up a simple plume of smoke; but from time to time, with intervals that may be very long, the mountain grumbles, trembles, and vomits torrents of fiery substances. It is then said to be in eruption. To give you a general idea of the most remarkable phenomena attending volcanic eruption, I will choose Vesuvius, the best known of the European volcanoes.