Artists had made 'plein-air' or open-air studies of the sky since the 17th century. It was recommended practice that artists should sketch the changing patterns in the sky at several times of day and in various weather conditions, in order to capture it in all its moods. Here Cels has painted billowing clouds against a blue sky, with two birds wheeling in the breeze.
The inscription on the reverse indicates that the pigment was thinned with a kind of turpentine.
The National Gallery has endeavoured to make as many images of the collection as possible available for non-commercial use. However, an image of this painting is not available to download. This may be due to third party copyright restrictions.
If you require a license for commercial use of this image, please use the National Gallery Company's Online Picture Library or contact them using the following: