The Twenty-One Balloons

Professor William Waterman Sherman, a retired schoolteacher, sets out to fly across the Pacific Ocean aloft 21 balloons. But when one of his balloons is punctured by a seagull, he goes off course and lands on the volcanic island of Krakatoa. The island is inhabited by 20 families sharing the wealth of a diamond mine. When the volcano erupts, the families scatter, and Professor Sherman is rescued by steamship who sees him floating in the ocean.