In passing out of the chamber into another passage the boys were obliged to stoop low in order to avoid what is called a dip.
After passing under the dip so close to the ceiling that the boys were obliged to lie down in the boat in order to protect their heads, they came to a large chamber which seemed to be fairly dry save in the center, where there was a depression of considerable size.
"Nothing doing here!" Will exclaimed as he flashed his searchlight around the place. "This chamber looks as if there hadn't been an ounce of coal mined here for a hundred years."
"Then let's get out," George proposed, "and make our way back to the shaft if possible. If we can't, we'll make noise enough to attract Canfield's attention and let him come and lead us out."
"Here we go, then," cried Will, giving the boat a great push toward the dip. "We can't get out any too fast."
The boat came up against a solid projection of rock!
"I don't seem to see any way out!" George exclaimed.
"Well, it's there somewhere!" declared Will.
"I see it now!" cried George. "It's under water!"
"Under water?" repeated Will.