Thanks to the efforts of photographers such as Charles Marville, Eugène Atget, and others, we have a rich record of Paris and its mid-nineteenth-century transformation. At street level, cameras documented the ubiquity of advertising. Looking skyward, photographers recorded such feats as the construction of the Eiffel Tower. From balloons, they captured a birds-eye view of the city’s changing structure. Photography’s “mechanical eye” fostered new ways of seeing that were later expanded in cinema.