The Painter of Air Copenhagen, 1868. A boy named Henry Jacob Knudsen watches the water and the ships with an intensity that foreshadows a life spent chasing horizons. He enters the Royal Danish Academy of Fine Arts in 1884, but the halls of academia cannot contain his restlessness. By 1886, lacking the recognition he seeks, he turns away from the classroom and toward the sea. The transition is sudden. He becomes a sailor, then a capta…