forts (the best-known is on the
hill above Maryport) guarding the Cumberland coast beyond its western end.
The details of his work are imperfectly known, for though many remains
survive, it is hard to separate those of Hadrian's date from others that
are later. But that Hadrian built a wall here is proved alike by literature
and by inscriptions. The meaning of the scheme is equally certain. It was
to be, as it were, a Chinese wall, marking the definite limit of the Roman
world. It was now declared, not by the secret resolutions of cabinets, but
by the work of the spade marking the solid earth for ever, that the era of
conquest was ended.

[Illustration]

But empires move, though rulers bid them stand still. Whether the land
beyond Hadrian's wall became temptingly peaceful or remained in vexing
disorder, our authorities do not say. We know only that about 142 Hadrian's
successor, Antoninus Pius, acting through his general Lollius Urbicus,
advanced from the Tyne and Solway frontier to the narrower isthmus between
Forth and Clyde, 36 m. across, which Agricola had fortified before him.
Here he reared a continuous rampart with a ditch in front of it, fair-sized
forts, probably a dozen in number, built either close behind it or actually
abutting on it, and a connecting road running from end to end. An ancient
writer states that the rampart was built of regularly laid sods (the same
method which had probably been employed by Hadrian), and excavations in
1891-1893 have verified the statement. The work still survives visibly,
though in varying preservation, except in the agricultural districts near
its two ends. Occasionally, as on Croyhill (near Kilsyth), at Westerwood,
and in the covers of Bonnyside (3 m. west of Falkirk), wall and ditch and
even road can be distinctly traced, and the sites of many of the forts are
plain to practised eyes. Three of these forts have been excavated. All
three show the ordinary features of Roman _castella_, though they differ
more than one would expect in forts built at one time by one general. Bar
Hill, the most completely explored, covers three acres--nearly five times
as much as the earlier fort of Agricola on the same site. It had ramparts
of turf, barrack-rooms of wood, and a headquarters building, storehouse and
bath in stone: it stands a few yards back from the wall. Castle Cary covers
nearly four acres: its ramparts contain massive and well-dressed masonry;
its interior buildings, though