touches to the apparatus they emerged from the globe and Dr. Bird entered.
"Come on, Carnes," he called. "No backing out at the last minute."
Carnes stepped forward with a sickly smile and joined the Doctor in the huge sphere.
"All right, boys; close her up."
The mechanics swung the outer door into place with a crane. Both the edge of the door and the surface against which it fitted had been ground flat and were in addition faced with soft rubber. Bolts were fastened in the door which passed through holes in the main sphere, and Dr. Bird spun nuts onto them and tightened them with a heavy wrench. He and Carnes lifted the smaller inner door into place and bolted it tight. Dr. Bird stepped to the telephone.
"Lower away," he directed.
From a boom attached to the Minneconsin's forward fighting top, a huge steel cable swung down, and the latch at the end of the cable was closed over a vitrilene ring which was fastened to the top of the sphere. The cable tightened and the globe with the two men in it was lifted over the side of the battleship and lowered gently into the water. Carnes involuntarily ducked and threw up his hand as the waters closed over them. Dr. Bird laughed.
"Look up, Carnes," he said.
Carnes gasped as he looked up and saw the surface of the water above him. Dr. Bird laughed again and turned to the telephone.
"Lower away," he said. "Everything is tight."
THE globe descended into the depths of the sea. Darker and darker it grew until only a faint twilight glow filled the sphere. A dark bulk loomed before them. Dr. Bird snapped on one of his huge floodlights and pointed.
"The Arethusa," he said.
The ill-fated vessel lay on her side with a huge jagged hole torn in her fabric amidships.
"That's where her boilers burst," explained the Doctor. "Luckily we have a hard bottom to deal with. Let's see if we can locate any of Mitchell's sea serpents."
He turned on other flood lights and swept the bottom of the sea with them. The huge beams bored out into the water for a quarter of a mile, but nothing unusual was to be seen. Dr. Bird turned his attention again to the wreck.
"Things look normal from this side," he said after a prolonged scrutiny. "I'll have the Minneconsin steam around it while we look it over."
In response to his telephone orders the ship above them swung around the wreck in a circle, and Carnes and the Doctor viewed each side in turn. But nothing of a suspicious nature made its appearance. The sphere stopped opposite the hole in the side and Dr. Bird turned to Carnes.
"I'm going to put on a diving suit and explore that wreck," he said. "If there ever was any danger, it isn't apparent now; and I can't find out anything until I get inside."
"Don't do it, Doctor!" cried Carnes. "Remember what happened to the other divers!"
"WE don't know what happened to them, Carnes. No matter what it was, there is no danger apparent right now, and I've got to get into that ship before I can get any real information. We could have lowered an under-sea camera and learned as much as we have so far."
"Let me go instead of you, Doctor."
"I'm sorry to refuse you, old dear, but frankly, I wouldn't trust your judgment as to what you had seen if you went alone; and we can't both go."
"Why not?"
"If we both went, who would work the air to let us back in? No, this is a one-man job and I'm the one to do it. While I am gone, keep a sharp lookout, and if you see anything unusual call me at once."
"How can I call you?"
