'I have done a great deal of skying - I am determined to conquer all difficulties...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.' (Constable in a letter to John Fisher, 23 October 1821)
Dating to circa 1822, this vivid study of storm clouds is an important addition to a series of en plein air sketches that Constable executed on Hampstead Heath during the summers and autumns between 1820 and 1823. This intense period of study was to prove fundamental to the development of his large-scale landscape paintings, in which the skies formed the 'key note, the standard of scale and the chief organ of sentiment'. Having started as a means of enriching his landscape paintings however, Constable's study of the sky became for him both a subject of scientific curiosity and an emotional obsession.
Constable first rented a house in Hampstead in the late summer of 1819. Over the next few years this expansive open terrain would prove crucial both to the improvement of his wife's health and to the advancement of his art. Hampstead had attracted painters from as early as the beginning of the 18th century, when Willem van de Velde the younger is known to have made sky studies on the Heath. By the early 19th century it was host to a number of landscape artists, including John Linnell, who had lodgings at the North End from 1822 and later moved to Collins Farm on the Heath itself, and the watercolour artist Frederick Nash, who erected his own observatory to study the sky in 1822 at his house off Hampstead Road.
A few Hampstead oil studies survive from October of 1820, however it was not until the summer of the following year that Constable was able to concentrate fully on his study of the sky. From his lodgings at Lower Terrace, which allowed him easy access to the western end of the Heath, Constable set about recording the ever-changing conditions and formations of the sky in an almost obsessive manner. Constable clearly relished the artistic challenges inherent in capturing this most elusive and volatile of subjects and was scrupulous in his approach, often annotated his sketches with the precise location, date, time of day and prevailing weather conditions. On a sketch dated 'Sepr. 10. 1821.' for example, Constable noted 'Noon. gentle Wind at West. Very sultry after a heavey [sic] shower with thunder. accumulated thunder clouds passing slowly away to the south East. very bright and hot. all the foliage sparkling and wet' (Cloud Study with Tree Tops and Building, private collection; Constable's Clouds, exhibition catalogue, Edinburgh and Liverpool, 2000, no. 36). Constable would often paint on consecutive days and sketches surviving from the 10th, 11th, 12th and 13th of September 1821 show that his approach could be as varied as the weather (ibid., nos. 36-9). On occasions he would even execute several studies in a single day, for instance on 27 September 1821 when he made sketches at ten in the morning, at noon and at four in the afternoon (G. Reynolds, The Later Paintings and Drawings of John Constable, New Haven and London, 1984, nos. 21.53-55), as if gathering proof not only of the different cloud formations created by the fluctuating weather conditions, but also of the speed of their transition. Constable was eager to gain a scientific understanding of these complex cloud configurations in order to depict them as accurately as possible; he followed contemporary studies in meteorology, notably Thomas Forester's Researches About Atmospheric Phaenomena (1813) and Luke Howard's essay on the classification of clouds in The Climate of London (1818-20).
In this study the sky is being swept along at great speed; dark blue and grey storm clouds, driven by a strong westerly breeze, threaten to engulf the billowing 'cumulus congestus' clouds and in turn the sun-filled sky beyond, while sheets of rain fall in strong diagonals from below the clouds. The energy of the brushwork conveys the speed of execution, as Constable hastens to record this transient effect. The overt (arc-shaped) scuff to the surface upper left may in fact have been caused by the artist as he hurried to pack his brushes and escape the ensuing rain. Constable noted on a study of 3 September 1821 'very sultry, with large drops of rain falling on my palette' (Study of Sky and Trees, Victoria and Albert Museum, London; Constable's Clouds, op. cit., fig. 21).
This study is remarkable for its scale, only four works of comparable size (measuring approximately 47.5 x 58 cm.) survive from 1822, now in Tate Britain, Birmingham Museum and Art Gallery, the Ashmoleon Museum (ibid., nos. 52, 53 and 58 respectively) and a further sheet dated 1 August (location unknown; G. Reynolds, op. cit., no. 22.17), however these are all on paper. While Constable used heavy millboard of this type throughout his career, he rarely employed it for cloud studies, opting rather for paper, which was often subsequently laid down on canvas or board. The slightly rough surface of the millboard adds a texture and energy to this study, especially in the dark storm clouds to the right where Constable has applied the paint very thinly.
Another significant feature of this sketch is the reserve that has been left along the lower edge for the foliage, which has helped to clarify an important aspect of Constable's working practice, namely that he painted the sky before filling in the landscape. This is of course in keeping with Constable's belief that the sky governed the chiaroscuro and entire mood of the landscape below. This sketch also falls at a key transitional moment, when Constable was shifting the balance of foliage and sky, and moving towards pure sky studies. As Timothy Wilcox describes in the exhibition catalogue Constable's Clouds: 'soon leaving the ground behind, he would appear to telescope into the heavens' (op. cit., p. 77). Study of Altocumulus Clouds in the Yale Center for British Art, New Haven, which is dated 13 September 1821, is believed to be the earliest extant cloud study to dispense with any vestige of tree or building (ibid., no. 39).