"I have some matches, in a waterproof case, if I didn't lose it out of my pocket," said Nort, feeling in his soaking trousers. "Here they are," he went on a moment later. And as his hands were drier than those of Bud or Dick, Nort opened the box and managed, after one or two failures, to strike a light.
As the little taper flared up the three boys on the rock saw, standing upright about in the centre of the large boulder a great handle, or lever, of copper. The metal gleamed dully red in the flickering light.
"What is it?" asked Bud, as Nort struck another light.
"I don't know," was the answer from Nort. "I discovered it when I was crawling about and feeling around. I thought, if worst came to worst, I could hold to this if the waters rose."
"They seem to be as high as they're going to get," said Bud. "But this sure is queer! Hold your match closer, Nort."
Another of the tapers was lighted, and across the pool came the voice of Snake Purdee, asking what was going on.
"There's some sort of a handle, or lever, here," answered Bud, as he examined it more closely. "It moves, too," he added as he laid his hands on it and pulled it toward him.
"Look out!" cautioned Dick, but it was too late.
Bud had pulled the copper lever toward him, and, in spite of its size and weight, it moved easily in what appeared to be a slot in the rock. It clicked slightly, as though connected with hidden mechanism.
Then, with a suddenness that was startling, a low but ever-increasing roar seemed to fill the cavern in which was the black pool. The roar grew louder and louder, and the very rock beneath their feet seemed to tremble.