5The days are getting shorter as summer's end approaches, which means it's time for the Harvest Festival, the last big event of the season, held by Mamie Fish, wife of millionaire railroad tycoon Stuyvesant Fish, at their grand "cottage," Crossways. The neocolonial mansion is decked out in artificial autumn splendor, and an extravagant scavenger hunt will be held. But the crowning jewel of the evening will be the guest of honor, Prince Otto of Austria.