speeding wheels of the new industrial production. The railroad 
was needed to cope with mechanized production, as much as 
to span the great distances of the continent. The steam 
railroad as an accelerator proved to be one of the most 
revolutionary of all extensions of our physical bodies, creating a 
new political centralism and a new kind of urban shape and 
size. It is to the railroad that the American city owes its 
abstract grid layout, and the nonorganic separation of 
production, consumption, and residence. It is the motorcar 
that scrambled the abstract shape of the industrial town, 
mixing up its separated functions to a degree that has 
frustrated and baffled both planner and citizen. It remained for 
the airplane to complete the confusion by amplifying the 
mobility of the citizen to the point where urban space as such 
was irrelevant. Metropolitan space is equally irrelevant for the 
telephone, the telegraph, the radio, and television. What the