estured to the haywire
apparatus with some pride. "Behold. Where there was junk is now a
radio."

Jan Miller said, "I don't believe it!"

Rick had to laugh. "I'm not sure I do, either. But let's try." He sat
down at the table and held the receiver to his ear. With the other hand
he began the laborious job of locating a sensitive spot on the razor
blade.

Dr. Gordon had told him that only an occasional spot on a blade will
work. Some blades have no such spots. Others have many.

Rick was beginning to think that he had one of the no-spot kind, or that
the whole idea was wrong, when he heard what he thought was a voice. He
hastily concentrated on the spot, and in a few seconds music flooded
into the earphone. He had caught a disk jockey in the process of
introducing a record. For a long moment he listened, then held out the
earphone with a broad grin. "Anyone care to listen?"

Everyone did. They took turns, with each application of the phone to an
ear accompanied by expressions of astonishment.

Barby looked at her brother with new respect. "It's just fantastic! How
on earth does it work?"

Dr. Miller chuckled. "I'm sure you don't want a full course in
electronics, Barby. Actually, it's simple enough. The signal from the
radio station is an alternating current that sets up a corresponding
current in the antenna wire. This current goes through the coil and is
rectified--that is, it's turned into pulsating direct current--by the
razor blade. The receiver then converts it into audible sound."

Barby sighed. "I'll just have to take your word for it. But it's a
miracle!"

"It may seem like one, but it's really the same kind of circuit you find
in a crystal set," Rick explained. "The razor blade acts like the
crystal. That's all."

The young people took turns listening to the station, located in a town
nearby. Within the hour there was a weather report promising clearing
skies before the end of the day. Later, in a roundup of local
announcements, they heard that the annual Sons of the Old Dominion
feast, postponed because of the storm, would be held the next night.

"That means we start keeping an eye on the ice-cream man tomorrow
afternoon," Rick said.

Scotty nodded. "First, we'd better make a survey of the terrain. He has
to approach by the road, but there are a million places he could go once
he got into the mine area."

Rick looked out the window. "The rain has stopped. Maybe we can
reconnoiter this aftern