"Suppose it should be Jimmie Maynard and Dick Thomson?" asked Tommy.

"Then we'd have the case closed up in a jiffy!" was the reply.

Before leaving that particular chamber, Tommy selected a large round
piece of "Gob," placed it in the center of the open space, and laid
another small piece of shale on top of it.

"What are you doing that for?" demanded Sandy.

"Don't you know your Indian signs?" demanded the boy. "This means,
'this is the trail.' Now I'll put one stone to the right and that
will tell these imitation Boy Scouts to turn to the right if they want
to get out."

"I guess they can get out if they want to," suggested Sandy.

Thirty or forty feet further on, where, following the string, the boys
turned again, this time to the left, Tommy laid another signal which
showed the direction to be taken.

"There," he said with a grin, "we've started them on the right path.
If they don't want to follow it, that isn't our fault!"

"We must be getting pretty near the shaft," Sandy said, after the boys
had walked for nearly half an hour on the backward track.

"Pull on your string," suggested Tommy, "and see if it stiffens up
like only a short length of it remained out."