On we drove, down the sloping sand. The green water rose about the windows. In a moment the periscope screen showed that we were entirely under water. We crawled steadily over the bottom of the sea, deeper and deeper. All the wonders of the hidden sea-life lay about us, bright corals and strange shrubs, curious rocks, and beautiful dells between them, through which silvery fishes and stranger monsters of the deep were moving. It grew darker, and Sam turned on the powerful searchlights. We moved on down into stranger regions. But I must not take space for that, for we were hastening toward a world that was weirder by far! In half an hour we closed the valves, which had been left open to let the water flood the tanks, and started the pumps. We were lifted above the ocean floor. We stopped the caterpillar tread, and set the screws into motion. In a few minutes the Omnimobile rose above the surface and splashed back into the blue waves like a gigantic dolphin of silver metal! I climbed out on the deck. The Florida coast was a bright green line in the west. The serene blue vault of the heavens was illimitable above us, and the deeper blue expanse of waters lay about in a flat, measureless plain. The machine throbbed almost imperceptibly with the motors, and the prow sent out two white wings of water. The plates were wet and slippery with the spray. I thrilled to feel again the motion of a powerful craft beneath me, to smell the salty tang of the air, and to feel the tingle of the salt mist upon my skin. We were making a good fifty knots, and I had to brace myself against the cool, damp wind of our progress. Thanks to her gyro-stabilizers, the vessel was perfectly steady. I stood there a long time, gripping the low rail, and lost in the wonders of sea and sky. I felt very much a part of all that splendid, sunlit world. I felt a deep, poignant regret at leaving it. But I found myself feeling--with a little surprise--that I could be willing enough to give up my life to save it! At last I went back into the conning-tower. Sam stood alert at the controls, with an odd, exultant light in his eyes, and with a smile of joy and confidence on his lean face. With his hands on the levers, he turned to me and said: "The little old machine's a wonder, Mel! She runs on sea, land, or air! It's a great feeling to drive her! She'd go anywhere! You know, I wish we had time to make a trial for the moon!" "There's no hurry about that!" I assured him heartily. "The moon will keep!" Presently I took the controls. Sam fixed dinner, and brought my meal in on a tray. Then he went to his stateroom. I enjoyed my spell at the controls. Indeed, as Sam had said, the handling of the machine gave one a strange sensation of power, of omnipotence, almost. It was the same feeling of unconquerable, careless power that a god might have enjoyed. I was almost sorry when Sam came to relieve me in the evening, and I had to go to my bunk.