Joe turned back to his work again. His heart was beating like a hammer now. Every muscle ached with the strain and his head felt as if it would burst. Joe knew he must have passed the four-minute period. How much longer could he stay under?
Not long, he feared. He had about reached his limit in this depth of water. He felt that he simply must let out a breath and draw in——
No! He couldn't do that. To breathe in now would mean slow suffocation. He must hold out.
He put the pointed end of the iron lever in a crack in the valve. He pressed with all his available strength. Nothing gave. Again Joe shoved down. His head seemed to swim, and it was black before his eyes. Still the imprisoned foot was caught.
Once more Joe pressed, and then, to his joy, he felt something give way. So suddenly did it happen that the bar fell from his hand. Then came a great rush of water. Joe had opened the valve so wide that the water was flowing out in a great volume.
He felt himself being sucked forward. Desperately he forced himself back. His foot, held under the root, seemed as if it would be torn from his leg.
Then he felt great arms about him. He knew them to be those of the diver. In the light of the electric lamp Joe saw the man pull his leg loose, and then, while consciousness almost left Joe, he felt himself being carried toward the surface.
The diver had been able to free himself when Joe opened the valve. In an instant he had signaled to be pulled up, and as he shot toward the surface, seeing Joe's great danger he had clasped him in his arms. Together the rescuer and rescued were pulled up, and an instant later Joe, who felt that he simply could not hold his breath another fraction of a second, found himself in the air and gulped in great mouthfuls of it. Oh, what a relief it was! For a moment, in the great need of it, he forgot what he had done.
But others did not forget it, and no sooner was it seen that the diver, alive, was out of the underwater trap, and that Joe, in his arms, had also come up, than a great cheer was shouted forth.
Eager hands lifted Joe and the diver to the top of the dam, and while some supported Joe, who was quite weak, others began to loosen the diver's helmet, for, until this was done, it was necessary to pump air to him.