"Because of the smash down below. The whole affair will go rushing down, mile after mile, at a headlong pace at last. It would be knocked to pieces on the bottom if it wasn't for that cord. But the weights will hit the bottom, and directly they do, the buoyancy of the sphere will come into play. It will go on sinking slower and slower; come to a stop at last, and then begin to float upward again. "That's where the clockwork comes in. Directly the weights smash against the sea bottom, the rod will be knocked through and will kick up the clockwork, and the cord will be rewound on the reel. I shall be lugged down to the sea bottom. There I shall stay for half an hour, with the electric light on, looking about me. Then the clockwork will release a spring knife, the cord will be cut, and up I shall rush again, like a soda-water bubble. The cord itself will help the flotation." "And if you should chance to hit a ship?" said Weybridge. "I should come up at such a pace, I should go clean through it," said Elstead, "like a cannon ball. You needn't worry about that." "And suppose some nimble crustacean should wriggle into your clockwork"-- "It would be a pressing sort of invitation for me to stop," said Elstead, turning his back on the water and staring at the sphere. * * * * * They had swung Elstead overboard by eleven o'clock. The day was serenely bright and calm, with the horizon lost in haze. The electric glare in the little upper compartment beamed cheerfully three times. Then they let him down slowly to the surface of the water, and a sailor in the stern chains hung ready to cut the tackle that held the lead weights and the sphere together. The globe, which had looked so large on deck, looked the smallest thing conceivable under the stern of the ship. It rolled a little, and its two dark windows, which floated uppermost, seemed like eyes turned up in round wonderment at the people who crowded the rail. A voice wondered how Elstead liked the rolling. "Are you ready?" sang out the commander. "Ay, ay, sir!" "Then let her go!" The rope of the tackle tightened against the blade and was cut, and an eddy rolled over the globe in a grotesquely helpless fashion. Someone waved a handkerchief, someone else tried an ineffectual cheer, a middy was counting slowly, "Eight, nine, ten!" Another roll, then with a jerk and a splash the thing righted itself. It seemed to be stationary for a moment, to grow rapidly smaller, and then the water closed over it, and it became visible, enlarged by refraction and dimmer, below the surface. Before one could count three it had disappeared. There was a flicker of white light far down in the water, that diminished to a speck and vanished. Then there was nothing but a depth of water going down into blackness, through which a shark was swimming.