Dozens and Dozens of Cousins and Cousins

A young boy, Peter, and his pilot friend fly a homemade balloon to Canada to pick up Peter's twenty-four cousins, bringing them back to Peter's home in California for his birthday. Along the way, they rescue a goose in distress. On their return trip, with all the cousins, the balloon is endangered and they become lost, but the goose comes back to rescue them.