THE SOUTH DOWNS 215
to outwit him by so transparent a device as that of the sieve. Then it is abundantly obvious on the most superficial investigation that if the salt water really wished to overspread the Weald there are plenty of Down gaps that already exist.
Originally there is not the slightest doubt the dyke denoted, not the combe but the camp that crowns the spur of the Downs just north of it; sometimes it is called the Poor Man's Wall. The camp is of considerable area—some forty acres— but the agger is not very imposing, and its direction is most irregular; it does not even follow the ground of the hill very exactly.
A couple of miles west on the main ridge at Truleigh Hill, overlooking Edburton, is an interesting earthwork that appears to have consisted originally of three very low but rather wide tumuli, the central one larger than the other two; a rather poor agger encloses the tumuli with a small space to the north. Southward, half-way to the sea, on Thunderbarrow Hill, is a largely obliterated ridge camp. A rough chalk road leads down from the close vicinity of Truleigh Hill to the Weald near Edburton. Like others of its kind it has been lowered several feet, partly by traffic but chiefly by water, and this has given rise to absurd tales of the Romans having excavated half-concealed roads that their troops on the hill might be able at any time to surprise the dwellers in the Weald. In this district may be well seen what is described in the Victoria History: "At the foot of the chalk hills is often found a thick bushy hedge, which can be followed for long distances, and also occurs under similar circumstances in other counties. ... It consists of a belt of small trees, among which maple, cornel,