Down and down the adventurers went, through some underground passage, it was evident.
“Are we all here?” called Jerry, his voice sounding strange and muffled in the chamber to which they had come.
“I’m here and all right, but I don’t exactly know what has happened,” replied the professor.
“The same with me,” put in Ned, and Bob echoed his words.
Just then the automobile came to a stop, having reached a level and run along it for a short distance.
“Well, we seem to have arrived,” went on Jerry. “I wonder how much good it is going to do us?”
“Supposing we light the search-lamp and see what sort of a place we are in,” suggested Professor Snodgrass. “It’s so dark in here we might just as well be inside one of the pyramids of Egypt.”
The acetylene gas lamp on the front of the auto was lighted, and in its brilliant rays the travelers saw that they were in a large underground passage. It was about twenty feet high, twice as broad and seemed to be hewn out of solid rock.
“This is what makes it so dark,” observed the professor. “I knew it must be something like this, for it was still daylight when we tumbled into the hole and we haven’t been five minutes down here. Run the auto forward, Jerry.”
The car puffed slowly along surely as strange a place as ever an automobile was in. The boys looked eagerly ahead. They saw nothing but the rocky sides and roof of the passage.