Poseidon, or Neptune, is represented in Greek mythology as a sea-god; but he is figured as standing in a war-chariot drawn by horses. The association of the horse (a land animal) with a sea-god is inexplicable, except with the light given by Plato. Poseidon was a sea-god because he ruled over a great land in the sea, and was the national god of a maritime people; he is associated with horses, because in Atlantis the horse was first domesticated; and, as Plato shows, the Atlanteans had great race-courses for the development of speed in horses; and Poseidon is represented as standing in a war-chariot, because doubtless wheeled vehicles were first invented by the same people who tamed the horse; and they transmitted these war-chariots to their descendants from Egypt to Britain. We know that horses were the favorite objects chosen for sacrifice to Poseidon by the nations of antiquity within the Historical Period; they were killed, and cast into the sea from high precipices. The religious horse-feasts of the pagan Scandinavians were a survival of this Poseidon-worship, which once prevailed along all the coasts of Europe; they continued until the conversion of the people to Christianity, and were then suppressed by the Church with great difficulty. We find in Plato's narrative the names of some of the Phoenician deities among the kings of Atlantis. Where did the Greek, Plato, get these names if the story is a fable? Does Plato, in speaking of "the fruits having a hard rind, affording drinks and meats and ointments," refer to the cocoa nut? Again: Plato tells us that Atlantis abounded in both cold and hot springs. How did he come to hit upon the hot springs if he was drawing a picture from his imagination? It is a singular confirmation of his story that hot springs abound in the Azores, which are the surviving fragments of Atlantis; and an experience wider than that possessed by Plato has taught scientific men that hot springs are a common feature of regions subject to volcanic convulsions. Plato tells us, "The whole country was very lofty and precipitous on the side of the sea, but the country immediately about and surrounding the city was a level plain, itself surrounded by mountains which descended toward the sea." One has but to look at the profile of the "Dolphin's Ridge," as revealed by the deep-sea soundings of the Challenger, given as the frontispiece to this volume, to see that this is a faithful description of that precipitous elevation. "The surrounding mountains," which sheltered the plain from the north, are represented in the present towering peaks of the Azores. Plato tells us that the destruction of Atlantis filled the sea with mud, and interfered with navigation. For thousands of years the ancients believed the Atlantic Ocean to be "a muddy, shallow, dark, and misty sea, Mare tenebrosum." ("Cosmos," vol. ii., p. 151.)