Sep 29, 2018
RAY: This puzzler was sent in by a fellow named Ed Cash.
Ed writes, "One of the ways that allied agents in World War II used to get microfilm past German guards was to hide it in hollow coat buttons-- not the kind that you have on your shirt, where the thread goes through, but the kind with the loop in the back like you'd have on a coat. The top of the buttons screwed on and off like a jar lid.
"This worked for a while, but somehow the Germans became aware of this particular trick and they started giving a twist to the buttons on the coat of anyone they weren't sure of, to see if it unscrewed.
"When the allies found out the trick had been discovered, the people in charge of preparing clothing for new undercover agents had to make a change.
"They made one change, and none of those hollow buttons were ever discovered again. "
What DID they do?
RAY: There were a lot of things they could have done. They could have applied some adhesive making them difficult to turn or they could have put some kind of a locking pin. But what they thought of was even better. They made the threads.
TOM: Left hand thread.
RAY: So when the Germans twisted the buttons, they in fact didn't come off, they got tighter. And after they failed in a few attempts, they gave up on it because they just figured out, they're not using that trick anymore.