With his hands in his pockets, the captain stood a few moments and thought, and then he went to work.  From the useless little vessel which, had belonged to the Rackbirds he gathered some bits of old rope, and having cut these into short pieces, he proceeded to pick them into what sailors call oakum.

Early the next morning, his two canvas bags filled with this, he started for the caves.  When he reached the top of the mound, and was just about to hold his lantern so as to take a final glance into its interior, he suddenly turned away his head and shut his eyes.

“No,” he said.  “If I do that, it is ten to one I’ll jump inside, and what might happen next nobody knows.”

He put the lantern aside, lifted the great lid into its place, and then, with a hammer and a little chisel which he had brought with him from the tools which had been used for the building of the pier, he packed the crevices about the lid with oakum.  With a mariner’s skill he worked, and when his job was finished, it would have been difficult for a drop of water to have found its way into the dome, no matter if it rose high above it.

It was like leaving behind a kingdom and a throne, the command of armies and vast navies, the domination of power, of human happenings; but he came away.

When he reached the portion of the cave near the great gap which opened to the sky opposite the entrance to the outer caves, the captain walked across the dry floor to the place where was situated the outlet through which the waters of the lake had poured out into the Rackbirds’ valley.

The machine which controlled this outlet was situated under the overhanging ledge of the cave, and was in darkness, so that the captain was obliged to use his lantern.  He soon found the great lever which he had clutched when he had swum to the rescue of Ralph, and which had gone down with him and so opened the valve and permitted egress of the water, and which now lay with its ten feet or more of length horizontally near the ground.  Near by was the great pipe, with its circular blackness leading into the depths below.

“That stream outside,” said the captain, “must run in here somewhere, although I cannot see nor hear it, and it must be stopped off by this valve or another one connected with it, so that if I can get this lever up again, I should shut it off from the stream outside and turn it in here.  Then, if that fellow comes back, he will have to swim to the mound, and run a good chance of getting drowned if he does it, and if anybody else comes here, I think it will be as safe as the ancient Peruvians once made it.”

With this he took hold of the great lever and attempted to raise it.  But he found the operation a very difficult one.  The massive bar was of metal, but probably not iron, and although it was not likely that it had rusted, it was very hard to move in its socket.  The captain’s weight had brought it down easily, but this weight could not now be applied, and he could only attempt to lift it.