ABSTRACT
The continuous urban aggregates in western Europe have been defined, officially and unofficially, in various ways in different countries. Since we want a common standard of measure we shall take the data provided by the International Urban Research Group in its book on The World's Metropolitan Areas. 1 Their definition of an urban aggregate, described as a metropolitan area, is as close as possible to that of the standard metropolitan area according to the United States Census. These areas have over 100,000 inhabitants, with at least one city over 50,000, plus the contiguous administrative divisions which have over two-thirds of the population engaged in non-agricultural occupations, or, alternatively, a density of population at least one-half of the density of the central urban core, or at least twice the density of the next ring of divisions at a greater distance from the urban core. On this basis, Europe, excluding the Soviet Union, had fifty agglomerations each with over one million inhabitants.
