This phenomenon was of course completely inexplicable to the ancient philosophers, and Aristotle is even said to have drowned himself in the Euripus in a fit of despair, since, with all his prodigious sagacity, he could not possibly solve the mystery. For us, who know that peculiar formations of the sea-bed and coasts are capable of considerably augmenting the force of the floods, and that tidal waves rushing into a narrow channel in opposite directions, and at different times, must necessarily produce irregular fluctuations of the waters, the phenomenon of the Euripus has ceased to be a mystery. CHAP. IV. MARINE CAVES. Effects of the Sea on Rocky Shores.--Fingal's Cave.--Beautiful Lines of Sir Walter Scott.--The Antro di Nettuno.--The Cave of Hunga.--Legend of its Discovery.--Marine Fountains.--The Skerries.--The Souffleur in Mauritius.--The Buffadero on the Mexican Coast. Whoever has only observed the swelling of the tide on the flat coasts of the North Sea, has but a faint idea of the Titanic power which it develops on the rocky shores of the wide ocean. Even in fair weather, the growing flood, oscillating over the boundless expanse of waters, rises in tremendous breakers, so that it is impossible to behold their fury without feeling a conviction that the hardest rock must ultimately be ground to atoms by such irresistible forces. Day after day, year after year, they renew their fierce attacks, and as in the high Alpine valleys the tumultuous torrents rushing from the glaciers tear deep furrows in the flanks of the mountains, thus it is here the sea which stamps the seal of its might on the vanquished rocks, corrodes them into fantastic shapes, scoops out wide portals in their projecting promontories, and hollows out deep caverns in their bosoms. Here, also, water appears as the beautifying element, decorating inanimate nature with picturesque forms, and the sea nowhere exhibits more romantic scenes than on the rocky shores against which her waves have been beating for many a millennium. How manifold the shapes into which the rocky shores are worn! how numberless the changes which each varying season, nay, every hour of the day with its constant alternations of ebb and flood, of cloud and sunshine, of storm or calm, produces in their physiognomy! Our coasts abound in beauties such as these; but pre-eminent above all other specimens of Ocean's fantastic architecture is Fingal's Cave, which may well challenge the world to show its equal.