Hampton ranch
again?"

Jack interrupted excitedly.

"No, Frank, don't you see!" he said. "Bob is thinking of the radio
here in the cave. Aren't you, Bob? I'm a simpleton not to have thought
of it before."

"Well," said Bob, "we've all been so excited, that's not to be
wondered at. But while I mounted guard here during your breakfast, I
had a chance to calm down and do some thinking."

Bob was eager to use the radio telephone at once, but Jack persuaded
him to eat breakfast first. The big fellow literally bolted his bacon,
bread and coffee, and then accompanied by Jack, while Frank mounted
guard, he retired to the inner room where the radio outfit was
located.

"Let's have a look around here before we try to telephone," said Jack.
"It will take us only a few minutes. And we ought to know what we have
captured. What say?"

"Fair enough," Bob agreed.

A cursory inspection quickly convinced Jack that the station was not
of recent installation, but had been put in about the year 1918. Much
of the equipment, while of the best at the time it was put in, had
been antiquated since by improved parts.

It was a complete two-way installation, however, comprising a
generator of practically sustained waves, a good control system to
modulate the output, and a ground system for radiating a portion of
the modulated energy as well as a receiver and a good amplifier.

"Here is this chimney in the rock about which Tom spoke," Jack pointed
out. "They have hooked up through this. And the antenna, I suppose, is
on top of the rock above us.

"This arc," he continued, advancing to the coils, "looks pretty strong
and seems to have a rather elaborate water-cooling system. I think it
is of foreign design, probably German. The Germans were early in the
field with radio telephony development, you know."

"All right," said Bob, who was beginning to grow impatient, "I'll take
your word for it. But what I want to know is, can we telephone my
father at your ranch?"

"Say, Bob, I'm sorry," Jack said quickly. "You know how crazy Dad and
I are over this radio telephone. But, of course, you are anxious to
get your father. Come on, let's try. I'll throw on the generator."

Suiting action to words, Jack shortly had the generator at work, while
Bob began calling through the air for his father.

"Be careful to use our code," Jack warned him. "You know Rollins said
these fellows had a powerful radio station at the Calomares ranch, and
if they