All was quiet after that. Hours must have passed. All the boys were sleeping at least fairly well when air and earth shook with a mighty explosion.
Instantly six bewildered high school boys leaped to their feet in alarm.
CHAPTER X
POWDER MILLS, OR JUST WHAT?
"If that's a thunderstorm," muttered Greg Holmes, barely half awake, "then it's going to be a dandy!"
But Dick seized him by one arm and shook him.
"Come to your senses, Greg! That wasn't thunder."
"No; but what was it?" wondered Dave.
"I'm going to dress and find out," rejoined Dick sturdily. He sat on the edge of his canvas cot and began to pull on his clothing.
BANG! All were awake enough now to appreciate fully the force of this second jarring explosion.