"I've got a book that tells how some boys had a garden in summer, and sold vegetables enough to buy all the sleds and skates and caps and mittens they needed for the next winter," said Johnny.

"Oh, ho! I can have all such things without having a garden."

"But they couldn't, and it's real interesting to read how they managed their little farm."

"Farm? I thought you said it was a garden."

"It was such a large garden that they called it their farm: it was an acre of ground."

"How much is an acre?"

"You know how many acres there are in the park?"

"How should I know?"

"You know it is a quarter of a mile on each side, don't you?"

"What of that?"