[Sidenote:—­20—­] Meantime war had again broken out in Britain, and Gnaeus Julius Agricola overran the whole of the hostile region.  He was the first of the Romans whom we know to discover that Britain was surrounded by water.  Some soldiers had rebelled and after killing centurions and a military tribune had taken refuge in boats.  In these they put out to sea and sailed around to the western portion of the country just as the billows and the wind bore them.  And without knowing it they came around from the opposite side and stopped at the camps on this side again.  At that Agricola sent others to try the voyage around Britain and learned from them, too, that it was an island.

As a result of these events in Britain Titus received the title of imperator for the fifteenth time.  Agricola for the rest of his life lived in dishonor and even in want because he had accomplished greater things than a mere general should.  Finally he was murdered on this account by Domitian, in spite of having received triumphal honors from Titus.

[Sidenote:—­21—­] In Campania remarkable and frightful occurrences took place.  A great fire was suddenly created just at the end of autumn.  It was this way.  The mountain Vesuvius stands over against Naples near the sea and has unquenchable springs of fire.  Once it was equally high at all points and the fire rose from the center of it.  This is the only portion of it that is in a blaze, for the outside parts of the mountain remain even now unkindled.  Consequently, as the latter are never burned, while the interior is constantly growing brittle and being reduced to ashes, the surrounding peaks retain their original height to this day, but the whole section that is on fire, as it is consumed in the course of time, has grown hollow from continual collapse.  Thus the entire mountain, if we may compare great things to small, resembles a hunting-theatre.  The outlying heights of it support both trees and vines,—­many of them,—­but the crater is given over to fire and sends up smoke by day, flame by night.  It looks as if quantities of incense of all sorts were being burned in it.  This goes on all the time, sometimes more, sometimes less.  Often it throws up ashes, when there is a general settling in the interior, or again it sends up stones when the air forces them out.  It echoes and bellows, too, because its vents are not all together but are narrow and hidden.

[Sidenote:—­22—­] Such is Vesuvius, and these phenomena regularly occur there at least once a year.  But all the other happenings that took place in former time, though they may have seemed great and unusual to those who on each occasion observed them, nevertheless would be reckoned as but slight in comparison with what now occurred even though they should all be rolled into one.  This was what befell.  Numbers of huge men quite surpassing any human stature,—­such creatures as giants are depicted to be,—­appeared now on the mountain, now in the country surrounding it, and again