It rose, it died away again, and then once more swelled to an amazing extent, after which it finally stopped as suddenly as it had begun.
Five scouts stared at each other. Billy rubbed his eyes as though he really began to believe he must be asleep, and passing through a vivid dream bordering on the nightmare.
"Hugh! what can it be?" demanded Alec, a bit pale with sudden excitement, for which in truth he could not be at all blamed under the circumstances.
For once the scout master seemed puzzled himself. He shook his head in a way that brought new consternation to the heart of Billy Worth.
"You've got me up against a hard proposition when you ask me that, Alec!" was what Hugh declared.
"Then you can't even give a guess, can you, Hugh?" Billy besought him.
"We all heard the racket, that's sure," muttered Stallings, as though he had possibly begun to suspect he might be a victim of some delusion, and wished to make certain the others were in the same boat as himself.
"And it sounded just like a dozen, yes, three dozen men shouting like anything," Arthur assured him.
"I wonder——-" began Billy, starting up eagerly.
"If you've got an idea hurry and tell us what it is!" urged the impatient Alec. "I'll be hanged if I can grapple anything, it's given me such a bad shock."