"Just as man is composed of earth, water, air and fire, so this body of the earth is similar. Whereas man has bones within himself, the supports and framework of the flesh, the world has rocks, the supports of the earth; if man has within himself the lake of blood, wherein the lungs expand and contract in breathing, the body of the earth has its ocean, which also expands and contracts every six hours with the breathing of the world; as from the said lake of blood arise the veins, which spread their branches through the human body; likewise the ocean fills the body of the earth with an infinite number of veins of water.
The same cause which moves the humorous in every species of animate bodies against the natural law of gravity also propels the water through the veins of the earth wherein it is enclosed, and distributes it through small passages. And as the blood rises from below and pours out through the broken veins of the forehead, as the water rises from the lowest part of the vein to the branches that are cut, so from the lowest depth of the sea the water rises to the summits of the mountain, where, finding the veins broken, it pours out and returns to the bottom of the sea."
— Leonardo da Vinci, 1490 (via iyatan)