“I’ve got a dime in my pocket,” he began.

“I’ll bet it’s plugged,” put in Pee Wee.

“I have a dime in my pocket,” repeated Billy with dignity, “and I’ll give it to the fellow that can guess my joke before I can count twenty. That shows how good I think it is.”

As Billy had calculated, this secured the instant attention of the boys, for it was nearing the end of the term, pocket money was running low, and a dime—well, a dime was a dime.

“Let’s see it,” said Sparrow cautiously.

Billy promptly produced it.

“There it is,” he said. “Take a good look at it, for that’s the nearest any of you will ever get to it. You couldn’t guess this joke in twenty years let alone twenty seconds.”

“All right,” said Fred impatiently. “Go ahead! Shoot!”

Billy leaned forward impressively.

“What’s the quickest change of nationality on record?” he asked.