Rick was reasonably sure the Blue Ghost appeared in a carbon-dioxide cloud, and he was beginning to have an inkling of how this was accomplished—in principle, if not in specific terms. There were, after all, he reasoned, only a few ways of creating a visible image. He was going through the list of possibilities, eliminating them one by one.
If the Frostola man was connected with the ghostly appearances, it was only necessary to keep track of that tall individual. This was Rick's plan, necessarily postponed because of the storm.
"Wish we had a radio," he said. "I'd like to get a weather report."
Scotty grinned sympathetically. He knew that Rick was impatient when there was detecting to be done.
"We really should have a battery radio," Dr. Miller said. "Power here is not very dependable in stormy weather. I think I'll get one, although that won't help now."
"What we need is a radio that doesn't depend on power," Jan Miller said. "Then it would always be ready."
Rick stared at the girl, not really seeing her. A radio without power. He remembered a long talk with Dr. John Gordon of the Spindrift staff about the principles of radio. Dr. Gordon had sketched a circuit that needed no power, and then had told Rick of how American ingenuity had produced what soldiers called a "foxhole radio."
"I saw an old transformer in the woodshed," he said suddenly. "May I have it, Dr. Miller?" At the scientist's nod, he addressed Jan. "I'll bet you can find me a cardboard tube. Then, if I can have an old razor blade and permission to take the receiver off the telephone for a while, I can make a radio!"
The scientist, the girls, and Scotty looked at him with disbelief. "He's gone off his rocker at last," Scotty muttered. "How can anyone make a radio out of junk?"
"I'll need a pencil stub, a few screws, and a piece of board," Rick added. "A safety pin would help, too."