Turning to the main central growth of cities, a successful business at or near the city centre which requires more space can secure it either by acquiring adjoining ground, by building higher in the air, or by moving away from the centre. To build higher in the air solves the problem in a banking and office district, but not in a retail shopping district, where ground floor frontage on traffic streets is required. Whether an adjoining lot is acquired or the shopkeeper himself moves, the result is the same, which is the starting of the movement away from the centre, a slow but endless procession. The fact that land is cheaper away from the centre has a slight tendency to further promote the outward movement, which continually evidences the unstable equilibrium between the centripetal force of economy in the transaction of business and the centrifugal force of cheap land. The uniform tendency as a city grows is toward greater concentration in the business centre and greater dispersion in the residence sections, and as long as there is an outward movement, so long is there certain to be a continual readjustment at the business centre to conform to it.

Utilization of shallow harbor for warehouses and railroads. Duluth.

Utilization of shallow harbor for warehouses and railroads. Duluth.

The various embryonic sections gathered closely together in the first small area of the city, in expanding largely influenct the location of utilities. Whatever the new building to be erected, whether retail or wholesale, shop or residence, It can either be placed next to similar buildings or apart from them. With this choice, buildings are usually placed adjacent to others of a similar kind, so that the general tendency for all sections is to extend continuously, expanding in breadth as the centre is left. One expensive residence, if not overcome by unfavorable factors, may be sufficient to attract similar buildings and create the most fashionable residence street in a city, as in a more marked way the royal palaces in Paris and London have created the most fashionable residence districts in those cities. This, however, does not mean that individual enterprise or whim can run counter to the orderly evolution of a city.

Union Railroad Depot, Toledo. An exceptional case of non utilization of frontage opposite an important depot due to railroad ownership of land. Many thousands of dollars of income thrown away by not making short time ground leases.

Union Railroad Depot, Toledo. An exceptional case of non-utilization of frontage opposite an important depot due to railroad ownership of land. Many thousands of dollars of income thrown away by not making short-time ground leases.

When the best residence district is determined, the main growth of the city is quite certain to follow it, as note the movement of retail stores after the best residences on Fifth Avenue in New York; on Boylston Street in Boston; on Michigan Avenue in Chicago; on Olive and Locust Streets in St. Louis; on Madison, Monroe and Jefferson Streets in Toledo; on Morrison and Washington Streets in Portland, Ore.; on St. Charles, Ca-rondelet and Baronne Streets in New Orleans, etc. The reason the best residence district rather than the largest residence district draws the city, is doubtless that the far higher percentage of purchasing power of the wealthy more than offsets the superior numbers of the poorer classes, and to the further fact that the shops patronized by the wealthy become fashionable, and hence sought by all classes as far as their means permit.

Clark Street, Chicago, in 1857. Showing raised buildings and sidewalks, as city level was altered.