156 COMPARATIVE ARCHITECTURE. The Arch at Orange is one of the finest examples of this type outside Italy, It has semi-attached Corinthian columns between the arches and three-quarter columns at the angles. Besides these, mention might be made of the Arch of Janus, Rome, in the Forum Boarium, built in the reign of Septimius Severus, a four-way arch built as a shelter at the junction of four roads ; and also the arches at Palmyra and in North Africa. Arches were also erected to form entrances to towns or bridges, and in such cases might serve the purposes of defence. Of this type of gateway the Porta Nigra, Treves, the Porte S. Andre, Autun, the Porte des Mars, Rheims, and the Porta Aurea, Spalato (Palace of Diocletian), are among the best known. Pillars of victory, or memorial columns, were sometimes erected to record the triumphs of victorious generals. Trajan's Column (No 58 b, 60 j, l), was erected in connec- tion with his Basilica (page 139), and stood in an open court with galleries around at different levels, from which the bas-reliefs on its shaft could be viewed. " The sculptures wind aloft And lead through various toils, up the rough steip The hero to the skies." The column, of the Roman Doric order, stands on a pedestal 16 feet 8 inches square, and 18 feet high, ornamented with sculptured trophies on three sides, and having a doorway on the fourth. The column is 12 feet in diameter at the base and is provided with an internal spiral staircase of marble, lighted by small openings. Its total height is 147 feet. The sculptures, numbering over 2,500 human figures, besides animals, and carved on a spiral band over 800 feet long and about 3 feet 6 inches deep, were probably intended to represent the unwinding of a scroll of parchment illustrating incidents of Trajan's war with the Dacians. There is a full-sized cast in the Victoria and Albert Museum. The column erected in a.d. 161 to the memory of Antoninus Pius and that erected to Marcus Aurelius in memory of his victories over the Germans (a.d. 167-179) were founded on the design of Trajan's Column. Rostral Columns, a type of memorial which, in the time of the emperors, was numerous, were erected to celebrate naval victories. Rostra, or prows of ships captured after a naval victory, were used in their ornamentation (No. 69 h), and a recital of the deeds which led to their erection was carved upon them. TOMBS. In contrast with those of the Greeks, tombs were numerous, and bear considerable similarity to Etruscan examples, in particular that of Regolini Galassi at Cervetri.
