d cautiously. He was working as fast
as he could, and he realized that more than a minute of his precious
four--or, at best, four and a half--had passed. And he had only begun.
Could he stand it? Could he hold his breath long enough to make the
rescue?

"I will do it! I will!" Joe told himself down there under the water.

Several times he put all the weight he could bring to bear on the iron
bar, and Joe was well muscled. But the foot was still held fast. Joe
was afraid of using too much force for fear of making a hole in the
boot, or of causing the diving suit to leak. But the foot would not
stir.

Joe wished he had a longer bar, so he could get more leverage, but
there was no time to signal for one. Nor could Tom Rand help him by
pressing on the end. The diver could not lean forward far enough.

"I've got to do it all by myself," thought Joe grimly.

Again and again he pried with all the force he dared use. Something
tapped him on the shoulder. He looked around to see the diver beckoning
to him. Joe leaned back and saw, by the motions made by Rand's fingers,
that the diver was trying to tell him to pry on the valve itself.

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