46 COLE : ANCIENT ENTRENCHMENTS NEAR WETWANG. 
The above eiitrenclimeiits serve to cut off promontories to connect 
the heads of dales, or else to fortify the water-parting, occasionally to 
afford access to springs, anjl apparently to supply lines of connnuni- 
cation with the coast on the high ground ; but, as a rule, they do 
not enclose any particular area as a fortified post. Fimber is an 
exception, and probably x\ldro, and one or two other points. As a 
rule they run down the sides of dales, but do not cross the bottom. 
There are, however, exceptions, as e.g. the double dikes at Fimber. 
It is very rare for an entrenchment to be carried along a dale bottom, 
but there are a few instances, as at Backdale, pointing for Aldro. 
A great many of the entrenchments marked on the map were 
determined by the Ordnance Survey, but numerous additions have 
been made by personal observation carried on for the last twenty 
years. After the in closure of the Wolds at the beginning of the 
present century, the land was brought into cultivation, witli the 
result that many of the old entrenchments were destroyed by the 
plough. The site of such may still be traced by an experienced eye, 
though the process of identification is sometimes slow. For instance, 
in a field of oats just before harvest, a couple of parallel green lines 
may be seen, whilst all the rest is turning brown. The surfiice soil 
is perhaps perfectly level, no sign whatever of an entrenchment. One 
has to wait four years before taking another observation, or, if cir- 
cumstances are not favourable, perhaps eight or twelve years. Then, 
if the green lines re-appear in identically the same direction, it may 
be confidently asserted that the greener corn is growing in the filled- 
up ditches of an old entrenchment. In this way field has to be linked 
with field till the restoration is complete. And here another guide 
steps in, for in the hedgerows a rounded elevation may often be seen 
in the otherwise level outline of the top of the hedge. When the 
hedges were first planted at the inclosure the mounds were then in 
existence, and the hedges ran over them. All has been ploughed 
level since in the open field, but the hedge protects the portion of 
mound under it, and, in a district where the hedges are so neatly 
trimmed as on the Wolds, the eye can readily catch the rounded line 
of hummocks in one hedgerow after another. Again in turnip fields, 
white lines of chalk may occasionally be traced marking the debris of 
the ploughed-down dike or rampart. 
