"No, thanks," said Charlie, "my curiosity is quite satisfied."
They retreated as cautiously as they had advanced, followed by the melancholy roar from below.
"It's the water that makes that noise," said Brown. "The water down there is evidently still in a disturbed state, and is regularly set in motion, and rushes up some sort of a blow-hole."
"Do you think it has any connection with that hot swamp and lake down south?"
"Without any doubt; perhaps we shall find that lake all burst up when we go down there."
They retraced their steps, and, by the aid of the surcingles held by the blacks above, emerged once more into the open air. They rested most of the day, and started back to what they now considered their main camp as soon as the evening grew cool.
Columbus and the other four blacks were there, and everything as they had left it.
"That was a smart trick," said Brown.
"What was?"
"In our hurry to start after Charlie, we left the journal and the copies we had made lying loose in the tent. If the grass had taken fire, or the niggers looted the camp, we should have lost all our work."