The wheel made the road, and moved produce faster from fields to settlements. Acceleration created larger and larger centers more and more specialism, and more intense incentive, aggregates, and aggressions. So it is that the wheeled vehicle makes its appearance at once as a war chariot, just as the urban center, created by the wheel, makes its appearance as an aggressive stronghold No further motivation than the compounding and consolidating of specialist skills by acceleration of the wheel is needed to explain the mounting degree of human creativity and destructiveness. Lewis Mumford calls this urbanization "implosion," but it was really an explosion. Cities were made by the fragmenting of pastoral modes. The wheel and the road expressed and advanced this explosion by a radiational or center-margin pattern. Centralism depends on margins that are accessible by road and wheel. Maritime power does not assume this center-margin structure, and neither do desert and steppe cultures. Today

The wheel and the road are centralizers because they accelerate up to a point that ships cannot. But acceleration beyond a certain point, when it occurs by means of the automobile and the plane, creates decentralism in the midst of the older central ism. This is the origin of the urban chaos of our time The wheel, pushed beyond a certain intensity of movement, no longer centralizes. All electric forms whatsoever have a decentralizing effect, cutting across the older mechanical patterns like a bagpipe in a symphony. It is too bad that Mr. Mumford has chosen the term "implosion" for the urban specialist explosion "Implosion" belongs to the electronic age. as it belonged to the prehistoric cultures. All primitive societies are implosive, like the spoken word. Rut "technology is explicitness." as Lyman Bryson has said; and explicitness, or

An airline executive who is much aware of the implosive character of world aviation asked a corresponding executive of each airline in the world to send him a pebble from outside his office. His idea was to build a little cairn of pebbles from all parts of the world. When asked, "So what?" he said that in one spot one could touch every part of the world because of aviation. In effect, he had hit upon the mosaic or iconic principle of simultaneous touch and interplay that is inherent in the implosive speed of the airplane. The same principle of implosive mosaic is even more characteristic of electric information movement of all kinds. Centralism and extension of power by wheel and written word to the margins of empire are creative of the direct force, outside and external, to which men do not necessarily submit their minds. But implosion is the spell and incantation of the tribe and the family, to whi

Under technological explicitness, even of the urban centralist structure, some men managed to break out of the charmed circle of tribal magic. Mumford cites the words of the Chinese philosopher Mencius as a comment on this situation: When men are subdued by force they do not submit in their minds, but only because their strength is inadequate. When men are subdued by power in personality they are pleased to their very heart's core and do really submit. As the expression of new specialist extensions of our bodies the congregating of people and supplies in centers by wheel and road called for endless reciprocal expansion in a spongelike action of intake and output, which has entrapped all urban structures everywhere in place and time. Mumford observes: "If I interpret the evidence correctly, the cooperative forms of urban