“Maybe, he did,” agreed Frank. “I didn’t feel like hitting it up with him this morning, felt kind of lazy, as if I had spring fever. It would be just my luck to have him make a discovery on the one morning I wasn’t along with him.”

Bob’s figure disappeared in a fold in the sandhills, and Frank remembering Jack’s disgust over interference in the radio receivers, began to question him about it while waiting for Bob to arrive.

“What was it like this time, Jack?” he asked.

“Just the same, only worse,” answered Jack. “Tune up to 1,375 meters for receiving and then comes that snarling, whining, shrieking sound. It’s steady, too. If it were dot and dash stuff, I might be able to make something out of it. But somebody somewhere is sending a continuous wave, at a meter length, too, that is practically never used. From 1,100 meters to 1,400 meters, you know, is reserved and unused wave territory.”

“I wonder what it can be,” said Frank. 7

Bob by now had approached within calling distance, and he was so excited that he began to run.

“What’s the matter?” called Frank.

“Somebody chasing you?” asked Jack, as the big fellow ploughed through the sand and halted before them.

Bob grinned tantalizingly.

“What would you give to know?”