“It’s a radio receiving set for hikers. It contains three ‘peanut’ tubes, Jack. See? And A and B batteries. I snap it around my waist. Like this. See?”

There it was. A complete receiving set. Around the bottom of the broad belt ran a shelf bracketed at right angle, and on it were the batteries, the three little tubes, and the various dials.

“Here,” said Frank, pointing, “I hook on the head-phone. As for aerial, this little loop turns the trick.” Lifting out what seemed to be the bottom of the cabinet, he disclosed a tiny loop beneath, laid in a shallow drawer. “And, Jack, you think you’re some punkins with your experiments in long-distance receptivity. Well, how far do you think I can receive?”

“I give up,” said Jack, laughing. “How far?”

“Two or three hundred miles,” Frank replied. “Pretty good, eh, what?”

“Certainly is,” said Jack. “Let me try it. Maybe, someone is broadcasting now.”

“No use,” said Frank. “I took a look at the local paper this morning and read the broadcasting program. Nothing on until 4 o’clock. And by then we’ll be at the bull fight.”

“All right,” said Jack. “Take it along, and we’ll try it there. I want to know whether it’ll work. If it does, we ought to get some fun out of it.”

Frank promised to do so, and the set was replaced in the box. Then Mr. Hampton and Mr. Temple returned, and the matter was forgotten in the more important matter of explaining Don Ferdinand’s telegram and repeating what Captain Cornell had learned about Ramirez from the former Ranger.

“Hope nothing has happened to my old friend,” said Mr. Hampton thoughtfully. “Didn’t give the address of the friends he’s staying with, did he, Jack? No? Well, we can’t look him up there, then. Some rich Mexican family living on the American side of the Border, I suppose.”