"Because you had the side stone on the other edge."

"I don't think I did!" argued Sandy.

The boys puzzled over the situation for a few moments, and then
proceeded down the chamber looking for the tramway rails.

They passed from chamber to chamber and finally came to a place where
the slope was upward.

"I guess we've struck it at last!" Sandy exclaimed.

"But there are no rails here!" Tommy argued.

"Then we're on the wrong track again," admitted Sandy.

He bent down to the rock with his searchlight and pointed out
evidences that the passage had once been laid with rails.

"When they strip a chamber or a counter gangway," he said, "they take
away the rails. It seems that we are now in a part of the Labyrinth
mine which has been worked out."

"I know what to do!" exclaimed Tommy. "I'll give the call of the
Beaver Patrol and tell those ginks who have been giving the call of
the pack that we're lost! That ought to bring them out of their
holes."

The Beaver call was given time after time, but no reply came.