海上云拱

When travelling back from Venice in 1840, Turner made sketches at Passau and Burg Ilz in a 'roll' sketchbook which was slightly smaller than those he generally carried with him. As well as the seven topographical views, the book contained three watercolour sky studies. In this subject, the expanse of water could represent the River Danube, but it is perhaps more probable that this was an effect he saw while crossing the Channel at the end of the tour.