Pompeii, Its Life and Art

by August Mau

The whitish limestone has a fine texture, without impressions of leaves, and is of an even color; it was to some extent employed as a substitute for marble. It was not quarried at Pompeii, and was not extensively used; the most important example of its use is in the later colonnade about the Forum. The white Carrara marble (marmor lunense) was preferred for columns, pilasters, and architraves; but colored marbles of many varieties, cut into thin slabs and blocks, were used as a veneering for walls and in the mosaic floors.

Bricks were used only for the corners of buildings, for doorposts, and in a few instances, as in the Basilica and the house of the Labyrinth, for columns; brick walls are not found in Pompeii. The bricks seen in corners and doorposts ([Figs. 11], [95]) are simply a facing for rubble work. They are ordinarily less than an inch thick; they have the shape of a right-angled triangle, and are so laid that the side representing the hypothenuse—about six inches long—appears in the surface of the wall. Sometimes fragments of roof tiles, more or less irregular in shape, were used instead. The bricks of the earlier time contain sea sand and have a granular surface, with a less uniform color; the later bricks are smooth and even in appearance.

The flat oblong roof tiles (tegulae), measuring ordinarily 24 by 19 or 20 inches, had flanges at the sides; over the joints where the flanges came together, joint tiles in the form of a half-cylinder (imbrices) were laid, like those in use at the present day ([Figs. 114], [117]).

The styles of masonry are characteristic and interesting. We may distinguish them as masonry with limestone framework, rubble work, reticulate work, quasi-reticulate work, ashlar work, and, in the case of columns and entablatures, massive construction.

The masonry with limestone framework dates from the earliest period. The walls were built without mortar, clay being used instead. Since this served only as a filling, without strength as a binding material, it was necessary to arrange the stones themselves in such a way that the wall would stand firm. This result was accomplished by using large, oblong blocks, not only for corners and doorposts, but also for a framework in the body of the wall; as shown in our illustration, alternate vertical and horizontal blocks were built up into pillars which would hold in place the courses of smaller stones that filled the intervening spaces. The material of the larger, hewn blocks, as well as of the smaller fragments, was Sarno limestone, with occasional pieces of cruma or slag.

Fig. 9.—Wall with limestone framework.

The rubble work, opus incertum, consists of fragments irregular in shape, of the size of the fist and larger, laid in mortar. The material used in the earlier times was ordinarily lava; later, Sarno limestone. Corners and doorposts at first were built of hewn blocks; afterwards bricks and blocks of stone cut in the form of bricks were used for this purpose, and in the latest period frequently brick and stone combined, opus mixtum or opus compositum—a course of stone alternating with every two or three courses of brick. An example of the opus mixtum is seen in the entrances of the Herculaneum Gate ([Fig. 113]). Rubble work is the prevailing masonry at Pompeii; in comparison the other kinds described may be considered exceptional.

The reticulate work, opus reticulatum, formed the outer surface of a wall, the inner part of which was built up with rubble. It was composed of small four-sided pyramidal blocks, of which only the base, cut square and smooth, showed on the surface; the tapering part served as a key to bind the block into the wall. These blocks, which measured from three to four inches square at the base, were laid on their corners, so that the edges ran diagonally to the horizontal and vertical lines of the wall; the pattern thus formed had the appearance of a net, hence the name. The material was in most cases gray, occasionally yellow, tufa. The corners and doorposts were at first made of the same kind of stone cut in the shape of bricks; later of bricks. This style of masonry was in vogue at Rome, and apparently also at Pompeii, in the time of Augustus ([Fig. 12]; see also the pedestal in the foreground of [Plate I]).