They were begun by Caracalla in the year 212, enlarged by Heliogabalus, and completed by Alexander Severus; their area being 140,000 square yards--length, 1840 yards by 1476. As many as 1600 persons could, it is said, bathe in them at the same time. The baths, properly so called, were 1720 feet in length and 375 in width, and they were surrounded by pleasure-gardens, porticoes, a stadium, &c. The reservoir was supplied by the Antonine aqueduct, which carried the water from the Claudian over the Arch of Drusus. The principal entrance to the baths was from the Via Nova, one of the favourite promenades of the ancient Romans, made by Caracalla. Among the works of art discovered in the thermæ may be mentioned the Farnese Hercules, the Colossal Flora, the Farnese Bull, the Atreus and Thyestes, the Two Gladiators, and the Venus Callipyge. The bronzes, cameos, bas-reliefs, medals, &c., found in the thermæ are too numerous to mention. The urns in green basalt now in the Vatican Museum, and the granite basins of the Piazza Farnese, formerly belonged to the Baths of Caracalla. The baths remained entire, both as regards their architecture and their internal decoration, until the middle of the sixth century, when the aqueducts were destroyed by Vitiges. [Illustration: BATHS OF CARACALLA.] The portion of this series of main chambers, with which all the others are connected, like the limbs of an organic body, was a rotunda. The open space at the foot of the Aventine was intended for a stadium. The games held in it could be viewed from the tiers of seats, which rose, as in a theatre, above the reservoir, still in existence, on the declivity of the hill. From this the building was supplied with water, conveyed to the different points by means of an aqueduct.