To begin with a paradox, the feature of Chicago is its featurelessness. There is scarcely any capital, ancient or modern, to which the site supplies so little of a visible reason of being. The prairie and the lake meet at a level, a liquid plain and a plain of mud that cannot properly be called solid, with nothing but the change of material to break the expanse. Indeed, when there is a breeze, the surface of Lake Michigan would be distinctly more diversified than that of the adjoining land, but for the handiwork of man. In point of fact, Chicago is of course explained by the confluence here of the two branches of the Chicago River. These have determined the site, the plan, and the building of the town, but one can scarcely describe as natural features the two sinuous ditches that drain the prairie into the lake, apparently in defiance of the law that water runs, and even oozes, down hill. Streams, however narrow and sluggish they may be, so they be themselves available for traffic, operate an obstruction to traffic by land; and it is the fact that for some distance from the junction the south fork of the river flows parallel with the shore of the lake, and within a half-mile of it, which establishes in this enclosure the commercial centre of Chicago. Even the slight obstacle interposed to traffic by the confluent streams, bridged and tunnelled as they are, has sufficed greatly to raise the cost of land within this area, in comparison with that outside, and to compel here the erection of the towering structures that are the most characteristic and the most impressive monuments of the town.