In several of the great cities of the United States, the last few years have witnessed a novel and characteristic development of the use of iron in architecture. In many structures on the older continent, this material has been frankly and effectively employed, forming the obvious framework of the erection, even when the leading motive was quite other than a display of engineering skill. The Crystal Palace at Sydenham and other erections have been referred to, in which iron has taken its place as the main component of structures designed more or less to fulfil æsthetic requirements: the guiding principle in “tall office buildings” in the cities of the Western continent is, on the contrary, avowedly utilitarian. Iron has, of course, long been used in the form of pillars, beams, etc., in ordinary buildings, and it is only the extraordinary extension of this employment of it, after the lift or elevator had been perfected, and the ground-space in great commercial centres was daily becoming more valuable, that has led to the erection of structures of the “sky-scraper” class in American cities. For a given plot at a stated rent, a building of many stories, let throughout as offices, will obviously bring to its owner a greater return than one of few stories. The elevators now make a tenth story practically as accessible as a third storey, and the tall building readily fills with tenants. No claim for artistic beauty has been advanced for these structures, which aim simply at being places of business, and if provision be made for sufficient floor-space and daylight, and for artificial lighting, heating, and ventilation, together with the ordinary conveniences of modern life, and ready elevator service, nothing more is required by the utilitarian spirit, that seeks only facilities for money-getting. These tall buildings are usually erected on plots disproportionately small, and the architectural effect is apt to be bizarre and incongruous, especially when the structure shoots up skyward in some comparatively narrow street amid more modest surroundings. They are really engineering structures, but invested with features belonging to edifices of quite another order of construction. If they are necessities of the place and period, and are “come to stay,” it cannot be doubted but that decoration of an appropriate and harmonious character will, in course of time, be evolved along with them, when the conventionality that clings to architecture shall be broken through, and a new style appear, as consistent, and therefore as beautiful, in relation to the “tall office building,” as were those of the Greek temple and the Gothic minster in their free and natural adaptation. [Illustration: PLATE IV. THE AMERICAN TRACT SOCIETY BUILDING. ] [Illustration: FIG. 26_d_.—_St. Paul Building, N. Y._ ]