Others shut their teeth together harder than ever, and these more determined fellows, it might be noticed, tightened the grip they had upon their sticks.

All eyes were turned again upon Elmer, who had listened to these remarks with an amused smile.

"Hold on your horses, boys," he said, raising his hand just then to still the rising dispute.

"Shut up, everybody; Elmer's got something more to tell us," Lil Artha cried.

The hubbub died away, and an eagerness to listen took its place; for every one of them was anxious to pick up points concerning the clever way their leader figured things out.

It was an important part of a scout's duty to learn how to read signs, not only when following a trail, but at all times.

And especially valuable would this qualification become when confronted by a baffling mystery such as the Hickory Ridge troop was now up against.

"Those who occupied this shack were four in number," Elmer began.

"How did you find that out?" asked Red.

"By the various tracks. So far as I could see there were just four separate kinds leading up to this place, and each one different."