Exceptions to this progression are due chiefly to topography, business remaining on a level if possible and climbing hills only under great pressure. A further exception to the normal would be where two or more good residence districts are located on opposite sides of the. main business section so as to balance each other, as in Fort Wayne and Knoxville.
Probably the most important movement within a city as it grows is the gathering together of those carrying on the same kind of business into special districts. This tendency was common in Rome and Constantinople thousands of years ago, and is in harmony with the law of evolution, that increasing differentiation is accompanied by increased integration. Retail stores cluster together at convenient points for their customers and not because they do business with each other. The chief attracting power of such a retail section seems to be the insurance to customers against failure to find within the section what they seek. Undoubtedly the selection within this special district is normally better than that in all the rest of the city combined, and shoppers are saved the time, trouble and uncertainty of seeking through scattered shops. While one shop may attract a customer and another make the sale, such an interchange of customers is probably in the long run closely balanced. The personal factor, or the business ability of managers to advertise and develop a business, is most influential in causing gradations of values in adjacent business locations. A successful shop continually enlarges the area from which it draws custom and diverts special currents of travel towards it. This attracts the notice of other shops in the same line of business, who, reasoning either that the location has helped their successful rival or that by moving near them they can secure some of their customers, move close to the successful store. Formerly it was held that the further a retail store was removed from a competitor the better, but this has been found to hold true only of those small stores which depend for business on the immediate neighborhood.
Example of absence of influence of public building. Post office in Chattanooga, erected twelve years ago, away from business center, has attracted no business.
Perry Street, Montgomery, Ala. A curious example of the most fashionable residence street ending abruptly in a meadow, only-three blocks from fine houses. Of course axial strength is not necessary for residence streets.
In many forms of business the clustering together of those transacting it finally crystalizes into an Exchange, which forms the centre of the district. Since the Exchanges are the result and not the cause of the special districts in which they are located, we must look back of them to find the causes for the location of various utilities. For example, the. leather district in fact that thirty or forty years ago Hanover Square was the centre of the dry-goods trade.
New York, was located in Beekman Swamp, on account of the wet ground suitable for tanning pits, and similarly in Philadelphia, the leather district was located on both sides of Dock Creek. There were banks on Wall Street long before the Stock Exchange was established, the location of the. banks and of the United States Sub-Treasury and Assay Office attracting the Stock Exchange, which in turn drew further Banks, Trust Companies and Brokers. The location of the Cotton Exchange apart from the dry-goods district would seem strange except for the