“That’s all right, then,” said Griggs cheerily. “Now, look here, I shall want you to lower it again so that I can press the bung-hole under water. Most likely I shall have to do this with my foot, because my hands will be wanted for holding on. You understand?”

“Oh yes, we see,” cried Chris.

“Then down I go,” said Griggs.

“Stop!” cried the doctor, and his companions drew a deep breath which sounded as if they were greatly relieved.

“What’s the matter? Knots loose?”

“No, but I don’t see that it is necessary for you to go down. We’ll let the barrel go into the water, and it will fill itself.”

“Not it,” said Griggs. “It will only be battered to pieces against the rocks there.”

“I don’t know,” said the doctor. “We’ll try. I don’t think we ought to let you go down save as a last resource.”

“Very well, then,” cried Griggs. “Suppose you try.”

The doctor had already joined the boys at the rope and helped to lower the barrel down to the surface once again, to be, as it were, literally seized by the current; and as those above held on there was a strange, hollow, echoing noise as it was banged from side to side for a minute or two, before Griggs cried—