This drawing shows the western end of Westminster Bridge over the River Thames. Work is still taking place on the parapet, and a barricade prevents access to the roadway. It is probably based on studies made shortly after Canaletto's arrival in England in the summer of 1746, but may have been executed later. The main structure of the drawing is provided with black chalk underdrawing, and incised arcs outlining the arches are visible in a raking light. The appearance of the drawing is distorted by the fact that the brown ink used for outlines has eaten into the paper and shows as light lines in the darker shadows. However, the bold composition remains impressive.The close focus on a relatively small part of a major public structure would have surprised a contemporary audience. Urban views were expected to be descriptions of important architectural features or of noteworthy events, or they were amusing depictions of street life. Canaletto's acute observations of previously unconsidered detail must have puzzled the average picture buyer, and fascinated fellow artists.