Earliest Knowledge of Volcanoes--Their Influence on Mythology and Superstition--Part taken by Volcanic Rocks in Scenery--Progress of the Denudation of Volcanoes--Value of the Records of former Volcanoes as illustrating Modern Volcanic Action--Favourable Position of Britain for the Study of this Subject. Among the influences which affected the infancy of mankind, the most potent were those of environment. Whatever in outer nature stimulated or repressed courage, inventiveness, endurance, whatever tended to harden or to weaken the bodily faculties, whatever appealed to the imagination or excited the fancy, became a powerful factor in human development. Thus, in the dawn of civilization, the frequent recurrence of earthquakes and volcanic eruptions throughout the basin of the Mediterranean could not but have a marked effect on the peoples that dwelt by the borders of that sea. While every part of the region was from time to time shaken by underground commotion, there were certain places that became specially noteworthy for the wonder and terror of their catastrophes. When, after successive convulsions, vast clouds of black smoke rose from a mountain and overspread the sky, when the brightness of noon was rapidly replaced by the darkness of midnight, when the air grew thick with stifling dust and a rain of stones and ashes fell from it on all the surrounding country, when streams of what looked like liquid fire poured forth and desolated gardens, vineyards, fields and villages--then did men feel sure that the gods were angry. The contrast between the peacefulness and beauty of the ordinary landscape and the hideous warfare of the elements at these times of volcanic fury could not but powerfully impress the imagination and give a colour to early human conceptions of nature and religion. It was not only in one limited district that these manifestations of underground convulsion showed themselves. The islands of the Ægean had their volcanoes, and the Greeks who dwelt among them watched their glowing fires by night and their clouds of steam by day, culminating now and then in a stupendous explosion, like that which, in prehistoric time, destroyed the island of Santorin. As the islanders voyaged eastward they would see, on the coast of Asia Minor, the black bristling lavas of the "Burnt Country," perhaps even then flowing from their rugged heaps of cinders. Or when, more adventurously still, they sailed westward into the Tyrrhenian waters, they beheld the snowy cone of Etna, with its dark canopy of smoke and the lurid nocturnal gleam of its fires; while from time to time they witnessed there on a still more stupendous scale the horrors of a great volcanic eruption.