“No, sir,” said Hardock, with a chuckle. “What do you say it is, Master Joe?”
The lad listened in silence for a few moments, and then said slowly,—
“Well, if I didn’t know that it was impossible, I should say that we were listening to the waves breaking on the shore.”
“It aren’t impossible, sir, and that’s what you’re doing,” said Hardock; and the boys started as if to make for the foot of the shaft.
“What’s the matter,” said Hardock, chuckling. “’Fraid of its bursting through?”
“I don’t know—yes,” said Gwyn. “What’s to prevent it?”
“Solid rock overhead, sir. It’s lasted long enough, so I don’t see much to fear.”
“But it sounds so horrible,” cried Joe, who suddenly found that the gallery in which they were standing felt suffocatingly hot.
“Oh, it’s nothing when you’re used to it. There’s other mines bein’ worked right under the sea. There’s no danger so long as we don’t cut a hole through to let the water in; and we sha’n’t do that.”
“But how thick is the rock over our heads?”