Constable, John (1776-1837). English. Medium: oil on canvas. Date: 1824. Barges passing a lock on the Stour; in the private collection of Baroness Carmen Thyssen Bornemisza, it has been sold only once since it was acquired from the artist. When bought at auction in 1990 for �10.8 million, it became the most valuable British painting ever sold at the time ? a record it held for 16 years; Provenance: Museo Thyssen-Bornemisza, Madrid, Spain.