A Tommy wearing rain cape and carrying picket posts, 1917 (c)

Watercolour by Second Lieutenant Richard Tennant Cooper, 1918 (c).

This watercolour is a detailed study for one of the figures in the centre foreground of his painting 'The Working Party'. It shows how the artist worked up sketches before scaling them for inclusion in his finished work. Cooper displays his talent as an illustrator - his work for magazines would often be worked in tone rather than colour so that it could be easily translated to black and white engravings for the press.

This evocative sketch of a soldier with mud clinging to his boots shows the conditions that soldiers endured on the Western Front. Trench foot was common among troops in the trenches. This painful condition caused by long immersion in cold water or mud results in swelling, blisters and open sores, and can lead to worse infections and gangrene.