Here on Earth you live in a world you call three dimensions—length, breadth and thickness. By that, you mean your bodies, and all material objects comprise three dimensions. Perfectly right. But you live on the surface of a globe. In general—with exceptions of course—your actions take place in but two dimensions. Your birds move in three dimensions more than you do. And your fishes.
Fishes! There you see my point! In the Marinoid world of water, to move vertically came as naturally as the horizontal movement. Hence, I say the bottom of the city, for Rax had a vertical dimension almost as great as either of its others.
The city was, I should estimate, of roughly circular form some quarter of a mile long and nearly as broad. Like a huge, low cylinder standing on end.
It was a fibrous city of growing sea-vegetation! Huge stalks planted like a thick forest of trees in the sandy ooze of the water-bottom, grew straight upward a thousand feet or more. Broad, leaf-like branches spread from them at the top, sustained in an upright position by air-bladders.
These upright stalks were the vertical girders upon which the fabric of the city was built. For eight hundred feet up they were pruned of their branches. Parasite growing vines had been guided laterally to connect the vertical stalks. And upon these, other rope-like vegetation was woven. The result was a series of tiers some twenty feet apart—one above the other—forty of them from top to bottom of the city.
The tiers were further cut up into segments which served as houses. I shall describe one in detail presently—the one they gave Nona and me at the time our great event took place.
Throughout the city there were both vertical and horizontal streets at intervals—up and down and along which the inhabitants swam or drifted. And occasionally there was cubical open space—a sort of three-dimensional park. One of these, the largest, occupied the exact center of the city, with the ruler’s home contiguous to it.
Have I made myself clear? The fabric of this entire city—the very walls and rooms of its honeycombed houses—was living, growing vegetation of the sea. It grew rapidly. It was easily trained to grow in desired directions. A third of a man’s lifetime, no more, would grow such a city as this.
One species of vegetation? No, there seemed a hundred—each one of them had its specific use and adaptability. It was curious stuff. You have marine vegetation in your great oceans of Earth. You may conceive what this was like. Tough, smooth, somewhat slimy main stalks. But porous—like the stalk of your banana tree. The leaves were intricate and beautifully shaped; and there were millions of tiny air-pods growing everywhere.