Technique and condition
This colour beginning was executed on white wove paper in overlapping washes of yellow and blue applied initially to very wet paper, creating bright mixed greens. Graphite pencil drawing can be seen in the clouds, to emphasise the forms already created by painting. The highlights of the river were left blank, while the less dazzling lights in the river were washed out with a brush-load of plain water. The bright blue of the sky was applied later to dried paper, which is the reason that these washes have very hard edges. Completing the sky last was Turner’s normal practice in oil paintings, and he quite often did the same in watercolour, especially in more developed compositions.
The bright blue of the sky is likely painted with Prussian blue, while yellow and brown earth pigments can be seen in the foreground washes. Mixing these gave a range of vivid greens for the landscape, which would have been difficult to achieve with the more traditional blue indigo.