The present wall is said to be sixteen Roman miles and a half in circuit, which would be not far from fifteen of our miles. I have often ridden round them on my morning’s excursions, or nearly round them, and I take this to be near the distance; though the present _enceinte_ of the Transtiberina, or the part of the town west of the Tiber, is much larger now, than when the wall of Honorius, or the present wall, existed in that quarter also. Paris, including soldiers and strangers, has often contained a million of souls, although the town has an unusual number of gardens, with many wide streets and public places, besides palaces and hotels without number; and yet Paris does not fill its walls, by perhaps a fifth of the entire surface. Were the _enceinte_ of Paris compactly built up, two millions might comfortably dwell within the walls, and at need, by packing the people, as they were evidently packed at Pompeii and Herculaneum, three millions. The circuit of the walls of Paris is about eighteen miles. This would allow Rome to contain a million and a half or two millions within the present limits; and what good authority is there for supposing it ever had more people? Rome was divided into fourteen quarters in the time of Augustus. These divisions have descended down to our own time, and, although the names are changed, it is probable they are essentially the same. Aurelian lived near the end of the third century, and in the fourth century these fourteen quarters bore the following names, viz. Porta Capena, Cœlimontana, Isis et Serapis, Via Sacra, Esquilina, Alta Semita, Via Lata, Forum Romanum, Circus Flaminius, Palatium, Circus Maximus, Piscina Publica, Aventina, and Transtiberina. It is easy to trace the situation of all of these quarters within the present walls. Is it probable that Rome increased so much in the two centuries and a half that succeeded Augustus, as to require, that a space contained in a circuit of sixteen Roman miles and a half should be extended to a circuit of fifty, in order to receive the people? I do not believe it.