Just before passing the walls, we find the Arch of Claudius Drusus, built by the senate in 745 A. U. C., eight years before the Christian era, and ornamented, as is said, with trophies of German victories. Over the arch, on the face towards the city, one may perceive indications of a frieze and architrave, and the bed moulding of the cornice, but none of the corona: there are also remains of a small pediment, hardly extending across the opening of the arch. All this belongs to the original edifice, and is easily distinguished from the aqueduct of Caracalla carried over it; to execute which, it appears to have been necessary to cut down the work internally, nearly as low as to the key-stone of the arch. On the external face are two marble columns of the Composite order. The architrave of these remains, but nothing above it, and all the rest of the edifice has been stripped of the marble covering with which it was once coated. I have already described to you the gate of St. Sebastian. Immediately after passing it, you enter a vineyard on the right, to see, as you are told, the _Sepolcro di Marte_; it is of neat brickwork; the bricks on the external facings being cut to a sharp edge, as in some other buildings which I shall describe to you: internally, we find a simple waggon-headed vault, with slight caissoons in stucco, but no other ornament; and niches for cinerary urns. After this are other fragments, all of sepulchres, for we are now on or near the Appian way. Names have been given, but without authority, and the ruins are mostly mere masses of rubble, to which no form can be assigned. Some however are larger, and contain vaulted chambers, others are domed. Indeed the form, the extent, and the materials of the more perfect remains all vary, but it would be tedious to enumerate them. On the left-hand side of the road, opposite to one of these, which is of considerable comparative importance, and formerly attributed to the Scipios, is the little church of _Domine quo vadis_, so called because St. Peter, having escaped from prison at Rome, met here our Saviour bearing his cross; and in these words, for he preferred Latin to Hebrew, Syriac, or Greek, asked him where he was going. Our Saviour replied that he was going to be crucified a second time. St. Peter it appears understood the hint, and returned to submit to the martyrdom required of him. This is not to be found in the Acts of the Apostles, but is not the less firmly believed on that account; and moreover you are shown the impression of our Saviour’s foot in the stone on which he stood. It was politic, at least, to weave all these little circumstances into the history of St. Peter; they became united to all the earliest impressions of the Romans, and are easily connected with the idea of St. Peter having been bishop of Rome, and of the consequent superior dignity and authority of that church.