The best ground of conjecture I can find concerning the greatness of ancient Rome is this: We are told by Herodian that Antioch and Alexandria were very little inferior to Rome. It appears from Diodorus Siculus that one straight street of Alexandria, reaching from port to port, was five miles long; and as Alexandria was much more extended in length than breadth, it seems to have been a city nearly of the bulk of Paris,86 and Rome might be about the size of London. {p159}
There lived in Alexandria, in Diodorus Siculus’s time, 300,000 free people, comprehending, I suppose, women and children.87 But what number of slaves? Had we any just ground to fix these at an equal number with the free inhabitants, it would favour the foregoing calculation.
There is a passage in Herodian which is a little surprising. He says positively that the palace of the emperor was as large as all the rest of the city. This was Nero’s golden house, which is indeed represented by Suetonius and Pliny88 as of an enormous extent, but no power of imagination can make