Nineteenth-century Paris is a laboratory for novel administrative and visualization techniques. After the end of the Ancien Régime, the city is no longer defined by the representation of a monarch, but by the movements and actions of the population and their relationship to a multitude of things. With extensive data collection and innovative technologies, the Parisian authorities attempt to respond to social crises, uprisings, and epidemics, and to regulate the urban complex of people and things. The phantasm of complete governability of the urban environment triggers imaginative processes that both utopically elevate and simultaneously destabilize administrative representations. This results in a complex dialectic of technology and imagination. In 19th-century Paris, these procedures and strategies are also developed.