Examples of Iron Buildings: Church al an example of an iron building- in the construction of which stone would have been de cidedly preferable not only' for practical reasons, but also from considera tions of beauty, the reader is referred to Figure 29 (pi. 4), which repre sents the church for the fortress at Diinaburg. It was constructed in 1866, of wrought iron, by Von Struve, under whose directions it was put together after having been transported in sections to its place of destination. This little building—intended for one hundred and fifty people only—is said to fulfil its purposes in every respect; its interior is attractive, calling to mind the Gr:.-cco-Russian style of architecture.
Garden Pemilian and of various iron structures that do not require full side-walls are shown on Plate 6 (figs. 1-3). Figure shows an elegant ornamental cast-iron pavilion per fected in a highly. characteristic manner; it was opened to the public in 1834, in the Botanical Garden at Munich. It was from the plans of the architect Bergmann, and was cast at the ducal Salm Iron-works. Figure 2 shows the cast-iron Friedrich-Atigust Tower, erected in 1854, on the Lobauer Berg, in Saxony. From an octagonal ground-plan it rises in prismatic form to a height of 93 feet, with a diameter of 147 feet; its walls are entirely. of open-work, and on its upper half are three galleries, which run all the way around and are reached by an open-work spiral staircase of one hundred and twenty steps, occupying the whole interior. The vari ous sections are connected by flanges and screws in the usual manner.
3 represents the cast-iron tower-like col umn of the artesian well at Grenelle, on the Place de Bretenil, in Paris; it is peculiarly graceful and characteristic in form, as well as ingenious and correct in construction. The broad substructure, which is partly of stone, and the tapering of the column, impart to the whole an appearance of g-reat stability. In the centre is the essential part—namely, a hollow cylinder, 26 feet in diameter, which is made of a number of pieces set together, and which serves as a casing to protect the stand- and supply-pipes of the well. Six uprights take the place of outer walls. Between these and the cylin der is a winding staircase which affords access to the three balconies of the column and firmly unites the chief interior and exterior parts. The six uprights on the exterior, moreover, are connected by the stair-railing and held together by the balconies. The open-work steps rest at either end upon suitable supports cast in the same substance as the inner cylinder and the pillars. The column is nearly No feet high, and weighs 167 tons. It is connected with the stone substructure by thirty-six bolts of inches thickness. All the portions of the construction are so calculated and dis posed as to resist the most violent winds.
Caibitol example of a building in which iron is used in imi tation of stone is given in Figure 4 (pl. 6). It is the dome of the Capi tol at Washington, work of this kind being frequently used in America.
The substructure—not given in the Figure—is of stone, as is also a portion of the inner circular base of the dome. The total height from the level of the street to the top of the Figure is 28734 feet, of which, however, 69 feet are upon the stone substructure. The octagonal base has an extreme diameter of 135 feet, while that of the upper hemispherical exterior part is 1o4 feet, and that of the rotunda in the clear is 94 feet: Thirty-two wrought-iron girders of lattice-work, tapering toward the top, form the chief supports of the " lantern," as well as of the three domes, placed one over the other; the innermost dome lias sunken panels and is left open above, so that the frescos on the vertex of the second dome, which is open at the sides, may be visible. The girders are so held together by a strong iron ring at their base that they cannot occasion any horizontal thrust. The various parts of the construction—for example, cornices, columns, balustrades, etc.—are all of hollow iron, and some are stiffened on the interior by lattice- and web-work. The dome and the wings of this immense building were designed and erected by Thomas U. Walter.
In regard to the above-mentioned iron building,rs in hall-form, the reader is referred to Figures 5 and 8 to t, which include three most inter esting examples.
The at Lyons, built by Desjardins in 1858, is represented in perspective cross-section in Figure 5. This building, which is beauti fully carried out, resembles a basilica—not merely because the whole in terior is divided into three aisles by arcades of columns, but also because the height of the middle aisle is greater than that of the sides; the middle aisle also, as is generally seen in the Roman basilicas, is twice as wide as either of the side aisles—that is, 39 feet, as against 19 feet of the sides; so that the total width in the clear is 78 feet. In its longitudinal measure ment we find in each row twenty-one columns, spaced feet from one another, which corresponds to a total length of 433 feet. The columns themselves are connected, both crosswise and lengthwise, by cast-iron open arches, and the angles left between the arches and the roof are filled in with web-work. A p.-,00d idea of this arrangement, as well as of the con nection of the various parts by flang-es and screws, is given in Figure 6; it also shows the characteristic and attractive forms, while Figure 7 shows the details, of the columns. The roof-framing is of wood, except that a saddle of iron rods and glass is set over the middle aisle, to serve as a sky light. In addition to the illumination obtained by this, and the glazed side-walls and ends, light is also admitted through glass in the higher side-walls of the middle aisle, and corresponding ventilation is afforded. There is a cellar under the whole. The weight of the iron-work is three hundred and fifty tons; the total cost was one hundred and ten thousand dollars.