"There may be another opening at the other end," said Tom. "It is certainly quite long."
They had advanced fully a hundred feet, and now found themselves in a chamber forty or fifty feet square. The ceiling was arched and so high that they could not touch it without jumping up.
"This is as good as a house," said Tom, "See how dry the flooring is. That proves that it is waterproof."
From the large chamber there were several passageways, all leading toward the bay.
"Which shall we investigate first?" asked Sam.
"Let us start at the right."
"All right, Tom; the right ought to be right," answered Sam lightly.
On they went once more, the flooring now sloping before them. Here there was considerable moisture, and they had to walk with care for fear of slipping down.
Suddenly a number of bats flew out of a hole nearby, dashing against the torches and against the boys themselves. The rush was so unexpected that each youth dropped his light and put up his hands to protect himself.
"Get out! Let me alone!" spluttered Sam.
