VESUVIUS IN 1737.
10,237,096 cubic meters; enough to cover a square mile twelve and a half feet in depth. Immense quantities of white ashes were thrown out, and the entire mountain was filled with rents and fissures, from which poured volumes of noxious vapors that suffocated man and beast. The quantity of ashes thrown out doubtless exceeded the volume of lava. In 1766 occurred another unusual convulsion, the mountain continuing vigorously active from March till December, vomiting lava streams and huge volcanic “bombs.” These last are masses of lava enclosing a bubble of gas, which is set free by the breaking of the bomb as it falls. In 1779 the lava streams for a time threatened Naples itself.
Sir William Hamilton, long time English ambassador in Italy, has left a careful record of the eruption of 1793-94. Passing by such features as, common to all its eruptions, we have noted elsewhere, we may note the more striking particulars: Millions of heated stones were thrown high in the air, and fell in beautiful curves about the cone. It might be likened to the bursting stars of our pyrotechnic displays. Nearly half Vesuvius was covered with fire. “Huge masses of white smoke were vomited forth by the disturbed mountain, and formed themselves at a height of many thousands of feet above the crater into a huge, ever-moving canopy, through which, from time to time, were hurled pitch-black jets of volcanic dust, and dense vapors, mixed with cascades of red-hot rocks and scoriæ. The rain from the cloud canopy was scalding hot.”
“As the lava rushed forth from its imprisonment it streamed a liquid, white and brilliantly pure river, which burned for itself a smooth channel through a great arched chasm in the side of the mountain. It flowed with the clearness of honey in regular channels, cut finer than art can imitate and glowing with all the splendor of the sun.” Various were the effects of stones thrown in. “Light bodies of five, ten or fifteen pounds weight, made no impression; but bodies of sixty, seventy and eighty pounds were seen to form a kind of bed on the surface of the lava and float away with it. A stone of three hundred weight that had been thrown out by the crater, lay near the source of the current of lava. I raised it up on one end and then let it fall in upon the liquid lava, when it gradually sank beneath the surface and disappeared. If I wished to describe the manner in which it acted upon the lava, I should say that it was like a loaf of bread thrown into a bowl of very thick honey, which gradually involves itself in the heavy liquid and then slowly sinks to the bottom.”
As it flowed down the mountain the brilliant whiteness disappeared. Then it began to wrinkle, where flowing slowly, like the cream on a pan of milk when poured off. Crusts formed, which were speedily cracked to pieces, as the current underneath pressed on. On such crusts a person may cross the stream, if not particular as to singeing his boots. Being cooled when near the bottom, yet forced on by the pressure behind, the whole mass “resembled nothing so much as a heap of unconnected cinders from an iron foundry, rolling slowly along and falling with a rattling noise over one another.”
This eruption continued from February, 1793, to July, 1794. Rocks were hurled two thousand feet into the air. The lava flowed from fifteen different sources, and pouring in one stream from twelve to forty feet thick, flowed three hundred and eighty feet into the sea, requiring but six hours from the time of the outbreak to reach the shore. The sea boiled for one hundred yards around. The town of Torre del Greco was destroyed, and a number of persons were killed. The natives insisted, when the paroxysm was over, on rebuilding on the old site. The Neapolitans have a jest concerning their own exemption from the calamities which Torre has endured: “Naples sins and Torre is punished.” The lava of this discharge is estimated at about twenty-one million cubic metres.
Several eruptions of Vesuvius have occurred during the present century. Of these, the most notable are those of 1822 and 1872. They have given us exact information upon a point where formerly there was only conjecture, viz: the height which the material thrown out may reach.