Happily for me, a recent visit to London coincided with the showing of “Turner and the Masters” at the Tate Gallery, Millbank. The exhibition ends there on January 31 but then travels on to Paris (Grand Palais, February 22 to May 24) and Madrid (Prado, June 22 to September 19). Although the show is intended to be thematic—or even didactic—dealing with the influence other major painters had on Turner’s development and the feelings of professional rivalry he is believed to have felt towards many of them, any exhibition involving the great Joseph Mallord William Turner is guaranteed to be a…