Why, did you know that if a beaver two feet long with a tail a foot and a half long can build a dam twelve feet high and six feet wide in two days, all you would need to build Boulder Dam is a beaver sixty-eight feet long with a fifty-one-foot tail?" "Where would you find a beaver that big?" grumbled the Humbug as his pencil point snapped. "I'm sure I don't know," he replied, "but if you did, you'd certainly know what to do with him.