Thus, on the first of November, 1170, the storm-flood, bursting through the dykes, submerged all the land between the Texel, Medenblik, and Stavoren, formed the island of Wieringen, and enlarged the openings by which the Zuiderzee communicated with the ocean. The inundations of 1232 and 1242 caused, each of them, the death of more than 100,000 persons, and that of 1287 swept away more than 80,000 victims in Friesland alone. The irruption of 1395 considerably widened the channels between the Flie and the Texel, and allowed large vessels to sail as far as Amsterdam and Enkhuizen, which had not been the case before. Whilst reading these accounts, we are led to compare the inhabitants of the Dutch lowlands with those of the fertile fields and vineyards that clothe the sides of Vesuvius: both exposed to sudden and irretrievable ruin from the rage of two different elements, and yet both contented and careless of the future; the first behind the dykes that have often given way to the ocean, the latter on the very brink of a menacing volcano. The tides which sometimes cause such dreadful devastations on the shores of the North Sea are, as is well known, inconsiderable, or even hardly perceptible in the Mediterranean, and thus many years passed ere the Greeks and Romans first witnessed the grand phenomenon. The Phœnicians, the merchant princes of antiquity, who at a very early period of history visited the isolated Britons,-- "Penitus toto divisos orbe Britannos,"-- and sailed far away into the Indian Ocean, were of course well acquainted with it; but it first became known to the Greeks through the voyage of Colæus, a mariner of Samos, who, according to Herodotus, was driven by a storm through the Straits of Hercules into the wide Atlantic 600 years before Christ. About seventy years after this involuntary discovery, the Phoceans of Massilia, or Marseilles, first ventured to follow on the track of Colæus for the purpose of trading with Tartessus, the present Cadiz; and from that time remained in constant commercial intercourse with that ancient Phœnician colony. With what eager attention may their countrymen have listened to the wondrous tale of the alternate rising and sinking of the ocean! Such must have been the astonishment of our forefathers when the first Arctic voyagers told them of the floating icebergs, and of the perpetually circling sun of the high northern summer. Thus the tides became known to the Massilians about five centuries before Christ, but in those times of limited international intercourse, knowledge travelled but slowly from place to place; so that it was not before the conquests of Alexander, which first opened the Red Sea and the Persian Gulf to Grecian trade, that the great marine phenomenon began to attract the general attention of philosophers and naturalists.