Following a suggestion by his patron Frederick Richards Leyland, Whistler used the musical term “Nocturne” to title more than thirty paintings of London after dark that he created in the 1870s. This one depicts barges moored to unload coal and other goods along the Chelsea docks; the chimneys and factories of Battersea appear in ghostly outline on the opposite shore. Whistler applied a brown underpaint to the coarsely woven canvas before covering the surface with thin layers of runny blue pigment. Later, he reworked the picture, and it is now more grey than blue, with touches of bright color to define the artificial urban light and its reflections on the river.