"Your workers, they're escaping!" cries the visitor. "You've got to stop them."
"Don't worry, they'll be back," says the American. And indeed, at exactly one o'clock the whistle blows again, and all the workers return from their break.
When the tour is over, the manufacturer turns to his guest and says, "Well, now, which of these machines would you like to order?"
"Forget the machines," says the visitor. "How much do you want for that whistle?"