"I guess this is about as hard as working in a coal mine," said Don. "I hope the rocks come to an end soon."
"This flooring has been thrown up by an earthquake," observed Bobert Menden. "We must be careful, or somebody may fall through some fissure. And don't wander away, whatever else you do."
The boys promised to be careful. But Menden's warning was not needed, for in that gloomy spot they were perfectly willing to keep close to one another and could not have been hired to separate.
"I believe we are coming to the end of this branch," said Dick, half an hour later.
"There is a small opening to the left," replied the Englishman. "We will try that;" and as before, he led the way. A narrow passageway was passed, and they came into a round chamber fifty feet or more in diameter. From overhead the water dripped constantly, and curious spiders and black bugs ran hither and thither, as the party approached with their torches.
"Oh, my! Look!"
The cry came from Don, and was taken up by several of the others.
"We've struck a cemetery of bones," said Bob; and he was right. On all sides of the chamber
