John Constable is one of the greatest painters of the English weather. His depictions of the sky are essential components of all his landscape paintings, from famous works such as The Hay Wain and Salisbury Cathedral from the Meadows to his numerous cloud studies painted on Hampstead Heath, culminating in paintings in which the landscape beneath the ever-changing sky is completely absent. Constable kept a weather diary and was endlessly fascinated by the sky. In a letter written in 1821 to friend John Fisher, Bishop of Salisbury, Constable commented, ‘That landscape painter who does not make his skies a very material part of his composition, neglects to avail himself of one of his greatest aids ... It will be difficult to name a class of landscape in which the sky is not the key note, the standard of scale, and the chief organ of sentiment.’