The theoretical interest of studying the Parisian passage revolves around the arrangement of pedestrian networks. Can a pedestrian network be augmented by inserting additional links of equivalent length? Can the observed use of these particular spaces be explained by a graph-theoretic interpretation of the urban pedestrian network or is there more to pedestrian behaviour? In this respect, the literature on the Parisian passage returns insistently to the themes of place: the social life and customs, the shop-owners, artisans, residents and habitués, the architectural frame and the goods on offer [Lemoine, 1989]. The on-going restoration of the passages is inspired by this rich social and literary history and guided by the imperative to preserve the architecture, but has so far failed to reproduce a brief but glorious hey-day (Figure 33.1). Is the passage primarily an urban room, a public space for exchange, commerce and social life, or does its use depend mostly on the movement of people from one street to another, incidentally passing through the short-cut provided? It has been claimed that it was usually a failure to provide a natural channel for existing movement patterns in the city and specifically to shorten one's trip from place to place that led to the failure of many of them [Geist, 1962].