This poster was commissioned by the Underground Electric Railway Company to promote travel to the summer sales of 1925. Mary Koop's vibrant design depicts a sea of brightly coloured umbrellas moving towards the entrance of a shop. The tall shop doorway mimics the form of a tunnel or bridge. As the assorted umbrellas pass underneath, they are closed until the journey home. The umbrella was used in numerous London Underground posters, particularly in the 1920s. Its pleasing symmetry lent itself perfectly to the bold geometric style of the time. It also presented an apt metaphor for the Underground as a refuge from the English climate. Koop's flamboyant umbrellas provide an injection of colour and a humorous slant on the unpredictability of the British summer.