to drop several degrees in an instant. Everyone
drew a long breath, faces were pressed against windows and expressions
of delight were heard in many parts of the sleeper.

They had entered a forest of tall pines, so tall that the lads were
obliged to crane their necks to see the tops.

"This is the beginning of the beginning," announced Professor Zepplin
somewhat enigmatically. "This is the forest primeval."

"I don't know," replied Chunky, peering through a car window. "It
strikes me that we've left the evil behind and got into the real thing."

"What is it, Professor?" asked Tad Butler.

"As I have said, it is a primeval forest. This great woodland stretches
away from the very base of the San Francisco mountains southward for a
distance of nearly two hundred miles. We are taking a short cut through
it and should reach Flagstaff in about an hour from now."

"Hurrah! We're going to see the Flagstaff in an hour," cried Stacy,
his face wreathed in smiles.

"A further fact, which is no doubt unknown to you, is that this enormous
forest covers an area of over ten thousand square miles, and contains
six million, four hundred thousand acres."

The boys uttered exclamations of amazement and wonder.

"If you'd said ten acres, I'd understand you better," replied Stacy.
"I never could think in such big figures. I'm like a rich fellow in
our town, who doesn't know what money is above a certain sum."

"Well, what about it?" demanded Tad.

"Up to fifty dollars, he knows how much it is, but for anything above
that it's a check," finished Chunky, looking about him expectantly.

No one laughed.

"Speaking of checks," said Ned Rector after an interval of silence, "did
you bring along that snaffle bit, Tad?"

"What snaffle bit?"

"The one we were going to put on Stacy Brown to hold him in check?"

A series of groans greeted Ned's words. Chunky grumbled something about
making a checker board of Ned's face if he didn't watch out, after
which the Professor turned the rising tide into other and safer
channels by continuing his lecture on the great Arizona forest.

As the train dashed on the Pony Riders were greeted with occasional
views of a mountain differing from anything they ever had seen. One
peak especially attracted their attention. Its blackened sides, and
its summit bathed in a warm glow of yellow sunshine, gave it a most
striking appearance.

"What is it, Professor?" asked Tad, with an inquiring gaze