"And he overthrew those cities and all the plain, and all the inhabitants of the cities, and that which grew upon the ground.
"But his wife looked back from behind him, and she became a pillar of salt.
"And Abraham gat up early in the morning to the place where he stood before the Lord:
"And he looked toward Sodom and Gomorrah, and toward all the land of the plain, and beheld, and lo, the smoke of the country went up as the smoke of a furnace." (Gen. xix, 23-28).
This is clearly the description of a volcanic eruption, for throughout the Bible things are described as they appear to be. When Moses speaks of brimstone and fire being rained upon Sodom and Gomorrah out of heaven, he is describing the phenomenon as it would appear to one looking at it. Of course, we know that in volcanic eruptions such things come to the earth through the crater of the volcano. The lava is thrown high into the air, and the hardening, but still red hot, ashes, rain down on the earth from the ash cloud that forms over the mountain. But, looked at from a distance they appear to fall or be rained down from the skies. In exactly the same way, Livy, the Roman historian, tells about showers of stones that fell from heaven on Mt. Albano near Rome for two whole days during the second Punic War. So, too, even Pliny, who had some pretensions to be considered a naturalist, in describing the appearance of Mt. Vesuvius during the terrible eruption of a. d. 79, when Herculaneum and Pompeii were destroyed, speaks of the red hot stones and ashes as falling from above. So, in reality, they did, although, as in the case of the cities of the plain, the materials forming the cloud came from the crater of the volcano below.
As to brimstone falling from the sky, this is by no means an unusual occurrence during many volcanic eruptions, since sulphur is a common material, often thrown out of the craters of some volcanoes.
Note also the statement that, when Abraham rose early in the morning and looked toward the place where Sodom and Gomorrah stood, he saw the smoke of the country go up like the smoke of a furnace. This was, probably, the smoke caused by the burning of the city, or even by the destruction of the crops in their fields, when ignited by the falling red hot ashes. It might also have been partly due to the burning of asphalt thrown out from the fissures in the ground, or to the showers of volcanic ashes that fell from the cloud formed during the eruption.
That the cities there were destroyed by a volcano far in the past appears from things outside of the Bible proper; for Strabo, the Greek geographer, refers to Jewish traditions that thirteen flourishing cities were swallowed up by a volcano, and this finds fair corroboration in the ruins along the western borders of the Dead Sea.
A writer referring to these eruptions says:
"The eruptions themselves have ceased long since, but the effects, which usually succeed them, still continue to be felt at intervals in this country. The coast in general is subject to earthquakes, and history notes several which have changed the face of Antioch, Laodicea, Tripoli, Berytus, Tyre, and Sidon. In 1793 there happened one which spread the greatest ravages. It is said to have destroyed in the valley of Balbec upwards of 20,000 persons."