Note 110
From Chapter 36 of the Decline & Fall

Such had been the sæva ac deformis urbe totâ facies, when Rome was assaulted and stormed by the troops of Vespasian (see Tacitus Histories iii. 82, 83); and every cause of mischief had since acquired much additional energy. The revolution of ages may bring round the same calamities; but ages may revolve without producing a Tacitus to describe them.