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 were to pick up your call and listen in there’d be trouble.”

“Right,” said Bob.  “But if Dave answers the signal, I’ll have to ask for father, because Dave doesn’t understand the code.”

It was Dave Morningstar who answered, the other ex-cowboy employed as mechanic and guard at Mr. Hampton’s radio plant in New Mexico.  And when he had tuned to the proper pitch to hear distinctly and Bob’s voice greeted him he was so surprised he stuttered and was incapable for a moment of coherent speech.  Then he began to pour a flood of questions at Bob, wanting to know where he was, how he happened to be able to radio, what had happened to the boys, why Tom Bodine, his partner, had failed to return, and so on.  But Bob cut him short.

“Stop it, Dave,” he said.  “We may be overheard.  Call father to the telephone, so I can speak in code.  Then I’ll explain.”