The sense which Vossius, in his _Observationes Variæ_, puts on this passage of Pliny errs widely in the other extreme. One manuscript of no authority, instead of thirteen miles, has assigned thirty miles for the compass of the walls of Rome; and Vossius understands this only of the curvilinear part of the circumference, supposing that, as the Tiber formed the diameter, there were no walls built on that side. But (1) this reading is allowed contrary to almost all the manuscripts. (2) Why should Pliny, a concise writer, repeat the compass of the walls of Rome in two successive sentences? (3) Why repeat it with so sensible a variation? (4) What is the meaning of Pliny’s mentioning twice the Milliarium if a line was measured that had no dependence on the Milliarium? (5) Aurelian’s wall is said by Vopiscus to have been drawn _laxiore ambitu_, and to have comprehended all the buildings and suburbs on the north side of the Tiber, yet its compass was only fifty miles; and even here critics suspect some mistake or corruption in the text. It is not probable that Rome would diminish from Augustus to Aurelian. It remained still the capital of the same empire; and none of the civil wars in that long period, except the tumults on the death of Maximus and Balbinus, ever affected the city. Caracalla is said by Aurelius Victor to have increased Rome. (6) There are no remains of ancient buildings which mark any such greatness of Rome. Vossius’s reply to this objection seems absurd—that the rubbish would sink sixty or seventy feet below ground. It appears from Spartian (_in vita Severi_) that the five-mile stone _in via Lavicana_ was out of the city. (7) Olympiodorus and Publius Victor fix the number of houses in Rome to be between forty and fifty thousand. (8) The very extravagance of the consequences drawn by this critic, as well as Lipsius, if they be necessary, destroys the foundation on which they are grounded—that Rome contained fourteen millions of inhabitants, while the whole kingdom of France contains only five, according to his computation, etc. The only objection to the sense which we have affixed above to the passage of Pliny seems to lie in this, that Pliny, after mentioning the thirty-seven gates of Rome, assigns only a reason for suppressing the seven old ones, and says nothing of the eighteen gates, the streets leading from which terminated, according to my opinion, before they reached the Forum. But as Pliny was writing to the Romans, who perfectly knew the disposition of the streets, it is not strange he should take a circumstance for granted which was so familiar to everybody. Perhaps, too, many of these gates led to wharves upon the river.