Mr. Penton sprang from the bench where he was just composing himself for a sleep.
"Did you hear that!"
"Yes, sir; we heard it," answered Rush.
"What was it?" questioned Bob, his head inclined in a listening attitude.
"It sounded like an explosion," said Steve.
"It was an explosion. That was dynamite, boys. Something is going on here. There should be no blasting in the mines to-night."
Mr. Penton ran to the telephone to find out what the explosion meant.
"It looks as though our work were cut out for us, Steve," said Jarvis in a low tone.
"I am beginning to think so myself," answered Steve, after listening intently for a moment.