“What do you suppose it is, and where do you suppose it comes from?” put in Gif.
No one could answer those questions. All was now silent, but presently they heard another series of explosions, and then the tapping continued steadily for several minutes. Then, however, the sounds died away.
“That’s got me guessing,” declared Jack, after the crowd had left the cavern. “We’ll have to tell Randy about this, and maybe we had better tell Captain Dale, too.”
Monday proved an exceedingly sultry day. The thermometer went so high that drills and exercises in the sun were all curtailed.
“Looks to me as if this was a weather breeder,” remarked the young captain to the others.
“Well, I don’t care what it does, if only it cools off,” grumbled Randy. “Why, I feel as if I was living in a bake oven!”
He had been told of the strange noises heard in the cavern at the bay front, and had been much interested. The boys had also spoken to Captain Dale, who had promised an investigation.
When the hour came for the cadets to retire the sky was so overcast that not a star was showing. A breeze had sprung up, and this was growing brisker every minute.
“I think we are in for a storm, and a good big blow with it,” announced Captain Dale. And then he told Major Ralph Mason to give orders that all the tent fastenings should be looked to.
“I’m sure our tent is down tight enough,” announced Randy, after he and his tent-mates had made an investigation.