The distinctive background view across Lake Geneva to the Le Môle peak in The Miraculous Draught of Fishes by Konrad Witz (1444) is often cited as the first Western rural landscape to show a specific scene. The landscape studies by Dürer clearly represent actual scenes, which can be identified in many cases, and were at least partly made on the spot; the drawings by Fra Bartolomeo also seem clearly sketched from nature. Dürer's finished works seem generally to use invented landscapes, although the spectacular bird's-eye view in his engraving Nemesis shows an actual view in the Alps, with additional elements. Several landscapists are known to have made drawings and watercolour sketches from nature, but the evidence for early oil painting being done outside is limited. The Pre-Raphaelite Brotherhood made special efforts in this direction, but it was not until the introduction of ready-mixed oil paints in tubes in the 1870s, followed by the portable box easel, that painting en plein air became widely practiced.