Roman Vault showing Tile Construction and Wooden Center. From a Drawing by Professor Hamlin. (Fig. 11.) Brick Arch Ribs connected through Tiles. Drawing by Professor Hamlin. (Fig. 12.) struction of great domes and vaults of very great width it was necessary to build a framework of brick ribs. (Fig. 12.) These ribs were supported during erection by wooden cen Theater of Marcellus, Rome. (Fig. 13.) ters and were united at frequent intervals by large tiles making a skeleton of cellular form. These cells were then filled with concrete and the whole shell covered with the same material. A vault or dome constructed as described formed a homogeneous mass, exerting no side or diagonal thrusts, but rested upon the supporting walls and piers like a huge hollowed lintel. When the core of the monument was thus completed the task of decorating it was undertaken. Artists and precious materials were commandered without regard to cost. The vaulted ceilings were embellished with moulded stucco, lavishly painted and gilded and the rough walls were enriched with marble veneering, columns and entablatures. Carvings of a decorative nature, and a profusion of statues added to the general architectural opulence of the whole. The Roman Arcade. (Fig. 13.) The decorative procedure of enveloping their arcuated masonry masses with columns, entablatures and their accompanying accessories confronted the Roman architects with the problems of harmonizing in the same design the |