344 ROMAN ARCHITECTURE. Part I. Castle of St. Angelo. The basement of this great tomb was a square, about 340 ft. each way and about 75 ft. high. Above this rose a cir- cular tower 235 ft. in diameter and 140 ft. in height. The whole was crowned either by a dome or by a conical roof in steps, which, with its centi-al ornament, must have risen to a height of not less than 300 ft. The circular or tower-like part of this splendid building was ornamented with columns, but in what manner restorers have not been quite able to agree; some making two stories, both with pillars, some, one of pillars and the upjier one of pilasters. It would require more correct measurements than we have to enable us to settle this point, but it seems probable that there was only one range of columns on a circular basement of some height surmounted by an attic of at least equal dimensions. The order might have been 70 ft., the base and attic 35 ft. each. Internally the mass was nearly solid, there being only one sepul- chral apartment, as nearly as may be in the centre of the mass, approached by an inclined plane, winding round the whole building, from the entrance in the centre of the river face. Besides these there was another class of tombs in Rome, called columbaria, generally oblong or square rooms below the level of the ground, the walls of which were pierced with a great number of little pigeondioles or cells just of sufficient size to receive an urn containing __^.. the ashes of the body, which had been burnt ac- cording to the usual Roman mode of disposing of the dead. Ex- ternally of course they had no archi- tecture, though some of the more important fam- ily sepulchres of tliis class were adorned internally with pilasters and painted ornaments of consid- erable beauty. In the earlier ages of the Roman Empire these two forms of tombs characterized with sufficient clearness the tAvo races, each with their distinctive customs, which made up the population of Rome. Long befoi-e its ex])iration the two were fused together so thoroughly that we lose all trace of the distinction, and a new form of tomb arose compounded of the two older, Avhich became the typical form with the early Christians, and from them passed to the Saracens and other Eastern nations. 224. Columbarium near tlip Gate of St. Sebastian, Kome.
