A watercolour showing volunteers building a pontoon bridge over the River Thames at Datchet. The river is shown in the foreground, with the bridge shown in the centre. Boats are shown on the water and a crowd is shown gathered on the far bank behind. Trees and buildings are shown in the background.
Inscribed on verso: Pcess Louise, Ponton Bridge across the Thames at Datchet, 1869

Princess Louise joined her mother, Queen Victoria, to watch a military review near WIndsor Castle on 26 June 1869. They started the day by watching the construction of a pontoon bridge over the Thames before watching field exercises in the Great Park.