Sec. 8. But powerful as these centralising forces have been during the
last century and a half, we are not justified in assuming that they
will continue to operate with gathering momentum in the future, and
that the results which are assigned to them will increase in
magnitude. Such an assumption would ignore two groups of counteracting
forces which are beginning to manifest themselves in the more advanced
industrial communities.

The first of these groups consists of a number of directly
counteracting or decentralising forces.

As a town grows in size the value of the ground on which it stands
grows so rapidly that it becomes economically available only for
certain classes of industrial undertaking, in which the occupation of
central space is an element of prime importance. In all large
commercial cities the residential quarters are driven gradually
farther and farther away from the centre by incessant encroachments of
business premises. The city of London and the "down town" quarter of
New York are conspicuous examples of this displacement of residential
buildings by commercial. The richer inhabitants are the earliest and
quickest to leave. As the factory or the shop plants itself firmly
among the better-class dwelling-houses, these inhabitants pass in
large numbers to the outskirts of the town, forming residential
suburbs which, for some time at any rate, are free from the specific
evils of congestion. This encroachment of the factory and the shop at
first has little effect, if any, in thinning the residential
population of the district. While the shopkeepers and their employees
live in the neighbourhood, and the factory workers can afford to pay
the rent for houses or lodgings near their work, the central
population will grow denser than before. But as the city grows in size
and commercial importance, an increasing number of the most central
sites will pass from manufactory premises and shops into use for
warehouses and business offices, and for other work in connection with
distribution and finance. The workers on these premises will, in the
case of the wealthier, be unwilling, in the case of the poorer be
unable, to live near their work; where factories and shops remain, the
great mass of the employees will not be able to afford house-rents
determined by this competition of a more valuable commercial use of
land. So we find that the number of inhabitants of the city of London
diminishes in each recent census, an