The title of one of the pictures which Constable sent to the Royal Academy in 1817 was A Scene on a Navigable River. In all probability this was the landscape called Flatford Mill, on the River Stour, now in the National Gallery, No. 1273, which is signed and dated ” Jno. Constable f. 1817.” He had exhibited a picture of Flatford Mill in 1812, in which, Benjamin West told him, he had attained ” real excellence.” He was, in-deed, so much in the habit of painting a favourite subject over and over again, from different points of view, but under the same title, that it is not always easy to decide their exact chronological order. It was also his practice, when a picture was returned on his hands unsold from the exhibition, to paint upon it again from time to time, with the idea of improving it, so that the date finally placed upon it does not always indicate the year in which the work was first begun.