It is comparatively easy to secure a sheet-metal cornice to a wooden building, or even to woodwork which is spiked to brick buildings; but it is considerably more difficult to properly secure a cornice to brick, stone, terra cotta, or to the structural ironwork of the modern fireproof building.

Fig. 8 shows a system of bracing well adapted for a cornice at the top of a brick wall. The framework or bracing shown, which is mostly composed of angle irons, should be built into the wall. These frames should be placed from 2 to 4 feet apart, according to the projection. The cornice is sometimes bolted to the framework after the wall is finished.

The strongest and best plan, however, is to attach the iron frames to sections of the cornice about 14 feet long and hoist the sections up, and set them on the wall when it has been leveled at the required height as at a. When lined up and in proper position, the frames are tied temporarily in place to keep the cornice from toppling over until the brickwork b, b is all filled in and has set. This mass of brickwork must be sufficient to more than counterbalance the weight of the cornice. If there is any danger of the cornice being too heavy for the counterweight, the legs c must each be tied separately to some beam or other rigid part of the building.

16 Iron Supports 385

Fig. 8.

There are, of course, many kinds of iron supports for cornices other than that shown in Fig. 8, but with a little judgment the student should be able to design a lookout for any position. The principal points to be considered in such a design are: (1) to obtain a band of iron which will follow, in a general way, the contour of the cornice; (2) a means to brace this iron band and prevent it from changing its shape; (3) a means of rigidly securing the iron band to the building; iron beams, or columns, being preferable for anchoring points.