“They come from the sea.”
“Is the sea very large?”
“So large that in certain parts it takes ships whole months to go from shore to shore. They are fast vessels, too, especially the steamships. They go almost as fast as a locomotive.”
“And what is to be seen at sea?”
“Overhead, the sky as here; all around, a large, blue, circular expanse, and beyond that nothing. One travels leagues and leagues, and yet is always in the middle of that blue circle of waters, as if one had not advanced. The rounded form of the earth, and consequently of the seas covering the greater part of it, is the cause of this appearance. The eye can take in only a small extent of the sea, an extent bounded by a circular line on which the dome of the sky appears to rest; and as the circle of the waters is ever being renewed while keeping the same appearance as one advances, it seems as if one remained stationary in the center of the circle where the blue of the sky merges into the blue of the sea. However, by dint of this continued advance one finally perceives a little gray smoke on the line that bounds the view. It is land beginning to show. Another half-day’s journey, and the little gray smoke will have become rocks on the coast or high mountains in the interior.”
“The sea is larger than the earth, the geography says,” remarked Jules.
“If you divide the surface of the terrestrial globe into four equal parts, land will occupy about one of these parts, and the sea, taken all together, the other three.”
“What is under the sea?”
“Under the sea there is ground, the same as under the waters of a lake or stream. Under-sea ground is uneven, just as dry land is uneven. In certain parts it is hollowed out into deep chasms that can scarcely be sounded; in others it is cut up with mountain-chains, the highest points of which come up above the level of the water and form islands; in still others, it extends in vast plains or rises up in plateaus. If dry, it would not differ from the continents.”
“Then the depth is not the same everywhere?”