The arches of Constantine and Septimius Severus are of the second category. They are covered with rich sculpture and are of very beautiful proportion. Famous arches are those of Orange in the south of France, Beneventum, Ancona, Rimini, Pola, and Athens. Everywhere, in fact, where a victory was to be commemorated, or the termination of a great military road to be marked, it was customary to erect an arch. Another method of paying homage to great men was to erect columns surmounted by their statues. The columns of Trajan and Antoninus in Rome are especially remarkable. The former is the higher and of the best workmanship. The pedestal upon which it rests is ornamented with elaborate carvings representing the arms of conquered nations, and is enriched at the four upper corners of its cornice by imperial eagles with garlands suspended between them. A wreath replaces the torus or round mould at the base of the column, and around the shaft is wound a ribbon of sculpture, representing a triumphal procession, which terminates at the capital. Isolated columns were also often employed for the inscription of legal notices, as boundary-marks, or for marking military limits. The gates at the entrances of the principal cities were similar to the triumphal arches. There are two especially fine examples in France, those of Autun and Treves. In these the attic story is replaced by a gallery connecting the two flanking wings, which are several stories in height, and contain chambers which it is commonly supposed were used as courts of justice. Roman camps were regulated and arranged with military precision, and were of two descriptions. The one, erected for temporary use, was defended by a rude palisade of branches and a ditch, the other, the “castra hiberna,” or winter quarters, was generally a permanent structure, built of brick, containing within a square enclosure the barracks, workshops, hospitals, and other necessary buildings. This enclosure was divided by cross-roads, passing through gates in the outer wall. The gate facing the enemy was called the porta prætoria, hence prætorian camp. Necrological monuments were built in various forms, from the simple tablet to the immense mausoleums of the emperors. Just without the walls of Rome are still to be seen the remains of the sepulchre of Caius Sestius, a large pyramid containing a chamber several feet above the ground level. Farther out, on the Appian Way, is the tomb of Cæcilia Metella, a cylindrical structure upon a square base, of considerable magnitude. The exterior is simple, the only decoration being a series of ox-skulls in the frieze. This building was probably originally surmounted by an earthen cone, after the manner of the Etruscan tombs. The tomb of Augustus was constructed in a similar manner but on a larger scale. The entrance was preceded by a porch and the exterior walls contained niches. The conical mound above was planted with trees and shrubbery.