158 COMPARATIVE ARCHITECTURE. towards the centre of the mass, were formed the sepulchral chamber and converging passages, which slope upwards from the ground level. On the whole, the structure has been much altered since its construction, being converted in the middle ages into a fortress by the Popes, and is now used as a military barrack. (c.) Pyramid tombs, probably due to the introduction of Egyptian ideas, were also adopted, as in the Pyramid of Cestius (B.C. 62-12), which is formed of concrete faced with white marble, and has an internal tomb-chamber, the vault and walls being decorated with figure paintings. (1^.) Smaller tombs, as isolated monuments, were often erected along the sides of roads leading from cities, as at Rome and in the Street of Tombs, Pompeii : ■' Those ancient roads With tombs high verged, the solemn paths of Fame ; Deserve they not regard ! o'er whose broad flinis Such crowds have roll'd ; so many storms of war. So many pomps, so many wondering reahns." — Dyer. These often have subterranean tomb-chambers for sarcophagi with niches for cinerary urns, and the walls and vaults were ornamented with colored reliefs in stucco, as in the Tomb of the Pancratii. Above the ground the tomb resembled a small temple, often with a prostyle portico, and the upper chamber contained portraits or statues of deities and served as mortuary chapels. {e.) Eastern tombs. — The districts of Palmyra, Jerusalem and Petra in Syria ; Caria in Asia Minor, and Algeria and Cyrene in Africa possess many examples, some rock-cut, and some structural. The Tomb at Mylassa, in Asia Minor, is one of the most interesting examples of the latter. The illustration (No. 52) will show its general characteristics. The Tomb at Diigga, near Tunis (No. 52 g), somewhat resembles that at Mylassa, but with a walled-up colonnade. In addition to the foregoing, memorial structures or cenotaphs were occasionally erected. The Monument of S. Rcmi, in Provence (b.c. first century) (No. 52 11), consists of a high pedestal ornamented with bas- reliefs and supporting a story of engaged Corinthian angle columns with arched openings between. Above is a circular story with fluted Corinthian columns, supporting an entablature and conical stone roof. The Igcl Monument, near Treves, Germany, is of similar design. AQUEDUCTS. The aqueducts, although more of an engineering than archi- tectural character, fulfilling a utilitarian purpose only, formed by
