Science, however, at length enabled us to overcome this disadvantage of saltness. By the process of distillation, men soon managed to procure enough water at least to save their lives. One captain of a ship, by accident, lost all his fresh water; and, before he could put into port to replenish, a gale of wind, which lasted three weeks, drove him far out to sea. He had no distilling apparatus on board, and it seemed as if all hope of the crew escaping the most horrible of deaths were utterly taken away. In this extremity the captain's inventive genius came to his aid. He happened to have on board an old iron pitch-pot, with a wooden cover. Using this as a boiler, a pipe made of a pewter plate, and a wooden cask as a receiver, he set to work, filled the pot with sea water, put an ounce of soap therein to assist in purifying it, and placed it on the fire. When the pot began to boil, the steam passed through the pipe into the cask, where it was condensed into water, minus the saline particles, which, not being evaporable, were left behind in the pitch-pot. In less than an hour a quart of fresh water was thus obtained; which, though not very palatable, was sufficiently good to relieve the thirst of the ship's crew. Many ships are now regularly supplied with apparatus for distilling sea water; and on the African coasts and other unhealthy stations, where water is bad, the men of our navy drink no other water than that which is distilled from the sea. The salts of the ocean have something to do with the creating of oceanic currents; which, in their turn, have a powerful influence on climates. They also retard evaporation to some extent, and have some effect in giving to the sea its beautiful blue colour. The ocean covers about two-thirds of the entire surface of the Earth. Its depth has never been certainly ascertained; but from the numberless experiments and attempts that have been made, we are warranted in coming to the conclusion that it nowhere exceeds five miles in depth, probably does not quite equal that. Professor Wyville Thompson estimates the average depth of the sea at about two miles. Of the three great oceans into which the sea is naturally divided--the Atlantic, the Pacific, and the Arctic--the Atlantic is supposed to be the deepest. There are profundities in its bosom which have never yet been sounded, and probably never will be.