Andreas Schelfhout, 'Landscape with Cumulus Clouds', about 1839

In 2007 the National Gallery showed this sketch for the first time in years. For a long time, experts thought it was by the little-known Belgian artist Gilles-Francois-Joseph Closson. Then the American artist Susan Bull Riley connected it to Andreas Schelfhout’s Landscape near Haarlem (Victoria and Albert Museum, London). Both works share the same blue sky and buildings on the horizon. The tower in the centre of our picture could be the bell tower of the cathedral of Saint Bavo in Haarlem. Although Schelfhout and Closson were contemporaries, there is no evidence that they ever met. We do not even know if they were ever in the same place at the same time.

Artists working outdoors followed certain rules. Teachers told them to first sketch in the important elements of the subject in either pencil or charcoal. Then they should focus on the middle distance rather than showing areas of landscape in the foreground. Someone has followed this approach here. The foreground remains unfinished. We can see details of the underdrawing. Infrared photography has revealed an elaborate landscape sketched in pencil. We can make out distant mountains, a hill town on the edge of a cliff and a herd of cattle. We ignore why these sketches were rejected. Perhaps the artist felt they were not good enough. So the paper was reused for this sky study.

Schelfhout was a successful landscape painter known mostly for his winter scenes. However, he also created many summer scenes like this one. He travelled throughout Northern Europe and visited England to study works by John Constable. Constable shared Schelfhout’s fascination with clouds. Constable created many detailed oil sketches of clouds from life in Hampstead. He also knew the works of the amateur meteorologist Luke Howard (1772–1864). Perhaps the accuracy of Schelfhout’s clouds came from studying Constable’s sky sketches?

Schelfhout trained several Dutch artists. He strongly believed in the benefits of open-air sketching. Some of his students, especially Johan Jongkind, would later become associated with The Hague School. This group championed painting outdoors. Jongkind became a forerunner of Impressionism and later mentored the young Claude Monet.