Landscape with Waterfall. Secondly, many 17th-century landscape paintings are unsigned and could be from pupils or copyists. Finally, fraudsters imitated Ruisdaels for financial gain, with the earliest case reported by Houbraken in 1718: a certain Jan Griffier the Elder could imitate Ruisdael's style so well that he often passed them off as genuine Ruisdaels, especially with figurines added in the style of the artist Wouwerman. There is no large-scale systematic approach to ascertaining Ruisdael's attributions, unlike the forensic science used to find the correct attributions of Rembrandt's paintings through the Rembrandt Research Project. Legacy Ruisdael has shaped landscape painting traditions from the English Romantics to the Barbizon school in France, and the Hudson River School in the US, as well as generations of Dutch landscape artists. Among the English artists influenced by Ruisdael are Thomas Gainsborough, J. M. W. Turner, and John Constable. Gainsborough drew, in black chalk and grey wash, a copy of a Ruisdael in the 1740s—now both paintings are housed in the Louvre in Paris. Turner made many copies of Ruisdaels and even painted fantasy views of a nonexistent port he called Port Ruysdael. Constable also copied various drawings, etchings and paintings by Ruisdael, and was a great admirer from a young age. "It haunts my mind and clings to my heart", he wrote after seeing a Ruisdael. However, he thought Jewish Cemetery was a failure, because he considered that it attempted to convey something outside the reach of art. In the 19th century, Vincent van Gogh acknowledged Ruisdael as a major influence, calling him sublime, but at the same time saying it would be a mistake to try to copy him. Van Gogh had two Ruisdael prints, The Bush and a Haerlempje, on his wall, and thought the Ruisdaels in the Louvre were "magnificent, especially The Bush, The Breakwater and The Ray of Light". His experience of the French countryside was informed by his memory of Ruisdael's art. Van Gogh's contemporary Claude Monet is also said to be indebted to Ruisdael. Similarly, Piet Mondrian's early abstract compositions the eventually led to the founding of De Stijl have been traced back to Ruisdael's panoramas. Among art historians and critics, Ruisdael's reputation has had its ups and downs over the centuries. The first account, in 1718, is from Houbraken, who waxed lyrical over the technical mastery which allowed Ruisdael to realistically depict falling water and the sea. In