On the banks of the Hudson one day in 1807, crowds gathered to watch Robert Fulton, an artist-turned-engineer, show off his steamboat. They called it "Fulton's Folly." Last week in Danbury, Conn, the scene was repeated with variations. The occasion: the first flight of the "Airphibian," a 150-h.p. light plane which can be bisected into an aluminum-bodied automobile.* The builder & demonstrator: Robert Edison Fulton Jr., an architect-turned-engineer and a descendant (he doesn't know the exact relation) of steamboat-builder Fulton.
The plane can carry two passengers (and 50 pounds of baggage) 400...