The Wonder Book of Volcanoes and Earthquakes

by Edwin J. Houston

The following letter from the younger Pliny, describing his flight with his mother from Misenum, is quoted from Dana's "Characteristics of Volcanoes."

"It was now seven o'clock [on the morning of August 25th], but the light was still faint and doubtful. The surrounding buildings had been badly shaken, and although we were in an open spot cloud, which was broken by zigzag and rapidly vibrating flashes of fire, and yawning showed long shapes of flame. These were like lightning, only of greater extent....

"Pretty soon the cloud began to descend over the earth and cover the sea. It enfolded Capreæ and hid also the promontory of Misenum." ... The flight was continued. "Ashes now fell, yet still in small amount. I looked back. A thick mist was close at our heels, which followed us, spreading out over the country, like an inundation." ... Turning from the roar in order to avoid the fleeing, terror-stricken throng, they rested. "Hardly had we sat down when night was over us—not such a night as when there is no moon and clouds cover the sky, but such darkness as one finds in close-shut rooms. One heard the screams of women, the fretting cries of babes, and shouts of men....

"Little by little it grew light again. We did not think it the light of day, but a proof that the fire was coming nearer. It was indeed fire, but it stopped afar off; and then there was darkness again, and again a rain of ashes, abundant and heavy, and again we rose and shook them off, else we had been covered and even crushed by the weight.... At last the murky vapor rolled away, in disappearing smoke or fog. Soon the real daylight appeared; the sun shone out, of a lurid hue, to be sure, as in an eclipse. The whole world which met our frightened eyes was transformed. It was covered with ashes white as snow."

Young Pliny and his mother returned to Misenum, and survived the perils to which they were exposed.

It was during this eruption that a large part of the old crater was blown off the mountain by the tremendous force at work.

There have been many eruptions of Vesuvius since the great eruption of a. d. 79. One of these occurred during the reign of Severus, a. d. 203. It was during this eruption that an additional part of the old crater of Somma was blown away.

Another great eruption occurred a. d. 472. Then great quantities of volcanic dust were thrown up into the air, and falling, covered practically all parts of Europe, producing darkening of the sun and great fear as far as the city of Constantinople.

But what was perhaps a still greater eruption occurred during December of 1631. This eruption spread great quantities of ashes over the country for hundreds of miles around, and great streams of mud rushed down the slopes of the mountain. Buccini gives the following account of this eruption:

"The crater was five miles in circumference, and about 1,000 paces deep. Its sides were covered with brushwood, and at the bottom there was a plain on which cattle grazed. In the woody parts wild boars frequently harbored. In one part of the plain, covered with ashes, were three small pools, one filled with hot but bitter water; another with water saltier than the sea, and a third with water that was hot but tasteless. But at length these forests and grassy plains were consumed, being suddenly blown into the air and their ashes scattered to the winds. In December, 1631, seven streams of lava poured at once from the crater and overflowed several villages, on its flanks, and at the foot of the mountain. Reisna, partly built over the ancient city of Herculaneum, was consumed by the fiery torrent. Great floods of mud were as destructive as lava. This is no unusual occurrence during these catastrophes for such is the violence of the rains produced by the evolution of aqueous vapors that torrents of water descend the cone and become charged with impalpable volcanic dust, and rolling among ashes, acquire sufficient consistency to deserve the ordinary appellation of aqueous lava."