"This. What makes a miller wear a white hat?"
Laddie thought over this for a moment or two and then said:
"He wears a white hat so the flour dust won't show so plain."
"Nope; that isn't it," Russ declared.
"Is it because nobody would sell him a black hat?" asked Laddie.
"Nope. Shall I tell you the answer?"
"No. Let me guess!" begged the smaller boy.
He gave several other answers, none of which, Russ said, was right, and at last Laddie murmured:
"I give up! Why does a miller wear a white hat?"
"To keep his head warm, same as anybody else!" laughed Russ. "Tom told me that riddle, too," he added.