The Cosmic Model In the cosmic model, the assertion is that the form of a permanent settlement should be a magical model of the universe and its gods. Such a crystalline city has all of its parts fused into a perfectly ordered whole and change is allowed to happen only in a rhythmically controlled manner. To achieve such form, specific phenomena are included, such as returning, natural items, celestial measurement, fixing location, centeredness, boundary definition, earth images, land geometry, directionality, place consciousness, and numerology. These are acknowledged in creating the city's form by devising methods for finding a good site, making boundaries, subdividing land, determining a center, connecting to celestial forms, fixing coordinates, controlling change, determining social structure, codifying rules, coordinating physics and metaphysics, and reinforcing form through ritual. The debates about the origin of cities: the spiritual significance in city genesis, argued by Adams, Rykwert, and Mumford, for example, versus the materialist arguments, such as those of Childe, Sjoberg and Jacobs, are discussed in the light of the cosmic model. Examples of the cosmic model are examined in the cases of Roman and Middle Eastern cities (Jerusalem and Babylon) and in cities in China (from the Han to Ming dynasties), India (the significance of the texts on habitation, the mandala form, Jaipur and Madurai), and in Mesoamerica (Teotihuacan, Tenochtitlan and the Mayan cities). Machine Model The concept of the city as analogous to a machine has a long history: it occurs often when there is no long-term goal in mind but the settlement has to be created hurriedly and its future growth will be determined by still unforeseen forces. Its form requires a few simple rules in order to get on with the urbanizing task and the outcome is factual, functional and without any attachment to the mystery of the universe. Among its attributes are convenience, speed, flexibility, legibility, equality, and speculation. These are explored in a set of cases from the 3rd century BC to contemporary times. The workers' dwellings built rapidly close to Egyptian mortuary sites are gridded in a per strigas form, "monotonously alike…, the very pattern of mechanically devised industrial dwelling." Unlike the form of their capital city, the Greek colonial trading cities of the 5th to 3rd centuries BC are made up of equalized rectangular blocks to allow a democracy of lots to its settlers and, according to Mumford, to provide the legibility necessary in a new climate of commercial trade. Despite Rykwert's assertions of the role of metaphysics in Roman city building, rules of castramentation (the cardo and decumanus alignments and equal lots) and centuriation (the fusing of urban and rural land geometries) dominate the creation of the 5,267 settlements built by the Romans. The 13th century colonial expansion of the 177 Bastide towns in south-western France follow an orthogonal order of a pair of double axes marking a center and surrounding equal-sized chequers. Perhaps the most complete and widely imposed practical handbook of city building instructions come from the colonization of the Americas by Spain according to the Laws of the Indies proclaimed in 1573. These laws govern site selection, street and block layout, orientation, central plaza, public buildings, walls, common lands, the distribution of lots, and even the style of buildings. The American land expansion, both religious and commercial, to the west is examined in the light of "grids of expediency", as is the 19th century expansion of the Manhattan grid as a system which "is the most cheap to build and the most convenient to live in." The assertions of Mumford and Sennett of the capitalist/grid relationship are challenged in this discussion. Finally, many of modern machine appropriations in city form, such as linearity, are explored as are many of the metaphorical attempts to link the form of cities, Archigram, for instance, to those of machines. Organic Model The third great normative model, which claims the city to be analogous to a living organism, is more recent, arising with the growth of biology in the 18th and 19th centuries. Its advocates are often critical of other models: the German urbanist, Hans Reichow, in his 1948 book on organic city planning, architecture, and culture, for instance, condemns "simple grids" or "products of the Grand Manner" as "static." The theory of the organic city rests on a number of assumptions about the nature of organisms. Among these is the assertion that an organism is an autonomous individual, that it has a definite boundary and is of a specific size. It does not change merely by adding parts but through reorganization as it reaches limits or thresholds. It contains differentiated parts but form and function are always linked. The whole organism is homeostatic, self-repairing and regulating toward a dynamic balance. Cycles of life and death are normal to organisms as is rhythmic passage from one state to another. From this flows the notion of the form of the organic city. It is a separate spatial and social unit made up internally of highly connected places and people. A healthy community is heterogeneous and diverse, as in balance as the nuclear family. The micro unit is the neighborhood, a small residential area, defined by Clarence Perry in 1929 as the support area for an elementary school, to which children, the most vulnerable of the human species, can safely walk. Like organisms, settlements are born, grow and mature, and if further growth is necessary, a new entity has to be formed. Thus there are states of optimum size, beyond which pathological conditions ensue. Greeenbelts not only ensure an intimate contact with nature but enclose healthy growth. This model has typical physical forms, among which radial patterns, anti-geometrical layouts, and a proclivity for natural materials. Often the organic idea is extended regionally to connect settlements to valleys, trails and other extended natural systems. There is an attraction to small-scale modes of production or services as opposed to large-scale synthetic processes. Often the model aligns itself with a socio-economic philosophy that sees increases in urban value as the result of communal rather than individual endeavor. Three cases are examined to locate these principles in practice. In the first case, the ideas and projects of Patrick Geddes are surveyed including his synoptic vision (folded paper, Valley Section, and plan for the Hebrew University), the need for civic inclusion (Outlook Tower), and the benefits of conservative surgery and cultural retention (Indian projects). The second case covers the work of Ebenezer Howard and his attempts to balance country and city, the garden city idea in the plans of Letchworth and Welwyn Garden city, and the details of density, landscape and site planning in the association of the organic with the picturesque. The third case covers the regionalism of the American plans of the early 20th century, the ideas of heterogeneous balance and Georgian socio-economic philosophy in the urban projects of Stein and Wright, including Mayer's plan for Chandigarh. Source: MITOpenCourseWare: Theory of City Form
Saturday, April 14, 2007
Understanding City Forms: Theoretical Discussion
According to faculty members at MIT, three core models have given form to cities throughout history. These are discussed below briefly. (Click on map to left to enlarge it.) The point of including this article on Conscious Communities is that we need to be aware of the "form" of communities.