"Somebody signaling?" stammered Merritt.
"That's it—watch!"
The smoke, which had not been visible for some seconds, now emerged from the stone chimney once more and the boys, fascinated, watched it closely with burning eyes. There was no doubt whatever about it now. It was signaling.
Four short puffs.
"Four dots—that's H," exclaimed Rob, trembling with excitement.
The smoke ceased.
"Here comes some more," shouted Merritt.
One short puff from the chimney.
"E, one dot, that's E sure enough," translated Rob.
The others stood like figures carved in stone as their leader read off the strange signals.