First, we have an arch which says on it, "Arcus ad Isis." Now if we compare this with the Arch of Constantine, we find it is the same without the attic. Then we have the amphitheatre without the upper story; then an arch (query, Arch of Domitian?). Then another arch with the words, "Arcus in Sacra Via Summa:" compare this with the Arch of Titus, and, minus the restorations, it will be found to be the same. Then there is a temple agreeing with the descriptions of that of Jupiter Stator upon the Palatine. All these buildings were erected or rebuilt about this time, and from being recorded on this monument of the Aterii, tend to show that Aterius was the architect of them. When perfect, the Colosseum consisted of four stories--the lowest, of the Doric order, 30 feet high; the second, Ionic, 38 feet high; the third, Corinthian, about the same height; and the fourth, also Corinthian, 44 feet high. The holes in the cornice with the corbels below them were to receive the masts that supported the _velaria_ on the outside. The numerous holes in the stone were made in the middle ages for the purpose of extracting the iron cramps that kept the stones from shifting. The long diameter is 658 feet, the shorter 558 feet; the arena is 298 feet by 177 in its widest part. The last performance was a bull-fight, held at the expense of the Roman nobles, in the year 1332. Many martyrs are said to have perished in the Colosseum during the persecutions of the early Christians, and among others S. Ignatius, who was brought from Antioch to be devoured by wild beasts. Benedict XIV. consecrated the building to the Christian martyrs, A.D. 1750. In excavating the Basilica of S. Clement, the Rev. Father Mullooly found (1870) the remains of S. Ignatius, and had them carried with great ceremony over the scene on the anniversary of his martyrdom. At the present day there remains sufficient to indicate the construction of the building, though but a small portion of the immense outer shell, which originally both adorned and formed an impenetrable girdle round the whole, has been preserved. In the interior, a great deal of rebuilding has been necessary for its preservation. Vast as the building is, its construction is easily understood; a simple segment of the whole serving to show how all the others succeed one another like the cells of a bee-hive. [Illustration: THE COLOSSEUM.]