By means of weight, the sun, the moon, the planets, yes, and even the countless multitudes of stars, are kept in their paths; in each case the inward pulling being counterbalanced by the impetus and outward pulling of a rapid rush. By means of weight, houses, rocks, stones rest firmly on the earth; by means of weight, the atmosphere is bound to the earth, the Ocean to its bed. Had sea-water no weight it might be scattered as fine water-dust through Space. A larger and heavier Earth would bind down the ocean yet more strongly, while a smaller and lighter Earth would have a weaker grip. Easily as the sea is now stirred by every passing breeze, an ocean such as ours on a little world like the Moon or Mercury would be more rapidly agitated. The waves would leap higher with less cause. So the Ocean, like the Land, is subject to law, knowing neither repose nor action except in obedience to Nature’s forces. When ocean-waters lie still as a mill-pond, they do so through an exact _poise_ of contending powers. When waves rush high and currents pour strongly, each movement is still in strict obedience to governing forces, which are themselves governed by law. Each movement is due to a long series of past movements; and each in turn helps to bring about a long series of future movements. There are no breaks in the chain. Every effect is also a cause. Currents here and drifts there; breezes here and hurricanes there; all these disturb the calm of the sea. Only for a brief spell, in one part or another, is the pull of opposing forces so far balanced that the water can lie still. And at most the stillness is comparative. Even in a so-called “dead calm” gentle heavings to and fro will be found. Absolute placidity in the ocean is a thing unknown. Even when the waters are at their stillest they are always being drawn steadily towards Earth’s centre. A perfectly level ocean would mean each portion of its surface being equally distant from that centre. The ocean ever strives after this ideal, but never attains to it; yet, century after century that aim is pursued, with a perseverance which might afford a lesson to ourselves. Despite all this change and restlessness, we talk of the ocean having a “level” surface. We picture it to our minds as being in outer shape the same as that of the Earth--a sphere. But this is not strictly true to fact. If we could look upon the Earth, with large far-seeing eyes, from a few thousands of miles off, we should find curious irregularities in the watery outline. Instead of showing all round a smooth surface, the ocean would be found to rise here and sink there, to be in one part higher, in another part lower. A man roving over the ocean, all about the Earth, would have in places to ascend undulations like hills, almost high enough sometimes to be called mountains, in other parts to descend declivities.