Page:Popular Science Monthly Volume 4.djvu/201

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tinents. Three-fourths of the surface of our globe is covered with water. The terra firma is divided chiefly into three great islands or continents, one extending from east to west, and constituting Europe and Asia; the second, situated to the south of Europe, in shape like a V with rounded angles, is Africa; the third is on the opposite side of the earth, and lies north and south, forming two V's, one above the other. If to these we add the minor continent of Australia, lying to the south of Asia, we have a general idea of the configuration of our globe.

It is different with the surface of Mars, where there is more land than sea, and where the continents, instead of being islands emerging from the liquid element, seem rather to make the oceans mere inland seas—genuine mediterraneans. In Mars there is neither an Atlantic nor a Pacific, and the journey round it might be made dry-shod. Its seas are mediterraneans, with gulfs of various shapes, extending hither and thither in great numbers into the terra firma, after the manner of our Red Sea.

Fig. 2.
PSM V04 D201 Mars surface chart.jpg
Chart of the Surface of Mars, showing the Distribution of Land and Water.

The second character, which also would make Mars recognizable at a distance, is that the seas lie in the southern hemisphere mostly, occupying but little space in the northern, and that these northern and southern seas are joined together by a thread of water. On the entire surface of Mars there are three such threads of water extending from the south to the north, but, as they are so wide apart, it is but rarely