Pompeii, Its Life and Art. August 1840-1909 Mau
easy grade could be established to the higher parts of the city; that the blocks along this important thoroughfare might not be too irregular in shape, the nearest parallel streets on the east were laid out in such a way as to follow the direction of Stabian Street. The street running south from the Capua Gate resumes, with slight variation, the north and south line of Mercury Street.
The public buildings of the city form two extensive groups. One group lies about the Forum (Plan II); with this we may reckon the Baths in the first block north, and the temples of Fortuna Augusta and Venus Pompeiana. The nucleus of the other is formed by the two theatres and the large quadrangular colonnade which, designed originally to afford protection for theatre-goers against the rain, was later turned into barracks for the gladiators (Plan III). There are in addition only four public buildings that need to be mentioned. Two are bathing establishments, the Stabian Baths, and those at the corner of Stabian and Nola streets. The third is a small building near the Herculaneum Gate, consisting of a hall opening on the street, with a base for a statue near the rear wall; this on insufficient grounds has been called a custom-house. The fourth, the Amphitheatre, lies in the southern corner of the city.
As the public buildings were thus located in clearly defined groups, it is not probable that many yet remain in the portion of the city which has not been excavated. We may expect to find only bathing establishments, and perhaps one or two temples. There were priestesses of Ceres and of Venus, but the sanctuary of Ceres has not been discovered. Mention is made also of a priest of Mars; but the temple of Mars, according to the precept of Vitruvius (I. vii. 1) would be outside the city.
A word should be added regarding the modern division of Pompeii into Regions, or wards, and Insulae. By an Insula is meant—in accordance with ancient usage—a block of houses surrounded on all sides by streets. The division into Regions was introduced by Fiorelli, and rests upon a misconception which has been corrected by more recent excavations. Fiorelli thought that the Capua Gate and the Nocera Gate were connected by a street, and that the city was thus divided by four streets (the assumed street, Stabian Street, Nola Street, and Abbondanza Street with its continuations) into nine Regions, marked on our plan with the numerals I-IX.
In each Region every block, or Insula, has its number, and in the Insula a separate number is given to every door opening on a street. This arrangement is convenient because each house can be accurately designated by means of three numbers.
On the plans the Insulae are designated by Arabic numerals, but in the text small Roman numerals are used for the sake of clearness; thus, Ins. IX. i. 26, means the first Insula of Region IX, No. 26.
The names of several of the more important streets, as of the better known houses, are given in the text in the English form.
CHAPTER VI
BUILDING MATERIALS, CONSTRUCTION, AND ARCHITECTURAL PERIODS
Six centuries lie between the dates of the earliest and the latest buildings at Pompeii; and in order to understand any structure rightly we must first of all ascertain to what period it belongs. It is indeed rarely possible to fix dates with exactness for the earlier time; but certain periods are so clearly differentiated from one another, that in most cases there is no room for doubt to which of them a building is to be assigned. Before undertaking to characterize these periods, however, it will be necessary briefly to notice what building materials were used, and how they were turned to account in construction.
Exclusive of wood, which was more freely used in Pompeii than in Campanian towns to-day, the principal building materials were Sarno limestone, two kinds of tufa (gray and yellow), lava, a whitish limestone often called travertine wrongly, marble, and brick.
The Sarno limestone (pietra di Sarno) is a deposit from the water of the Sarno, and is found in beds along the course of the river. It contains many impressions of the leaves and stems of plants, and varies greatly in compactness; it closely resembles the Roman travertine, except that it has a more decided yellowish tint.
Gray tufa is a volcanic dust which has been hardened by the presence of water into rock. It has a fine grain, and is easily worked; it was quarried in the vicinity of Nocera. The volcanic dust which formed the yellow tufa was thrown out in an earlier period, when the Sarno plain was still a part of the sea, and so hardened in salt water; it is more friable than the gray tufa, and not so durable.
The lava, which came originally from Vesuvius, was quarried at Pompeii. Three varieties may be distinguished, differing in density according as they were taken from the lower or the upper strata: solid lava, or basalt, which, being heavy and extremely hard, was extensively used for pavements and thresholds; slag, like the scoriae found on the sides of Vesuvius to-day; and cruma, the foam of the lava stream, which is light and porous, but on account of its hardness has good resisting qualities.
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