used the clefts was formerly continuous for fifty miles through the
great dome of chalk which extended over what is now the Weald. The
elevation of this "dome," caused by the shrinking and crumpling of the
earth's crust and consequent rise of the lower strata, was never an
actual smooth rise and fall from the sea to the Thames valley; through
the ages during which this thrust from below was in progress the crown
of the dome would be in a state of comparatively rapid disintegration,
and it is because of this that we have no isolated masses of chalk
remaining between the two lines of hills. The highlands called by
geologists the "Forest Ridge" are in the centre and are the lowest
strata of the upheaval; they are the so-called Hastings sands which
enter the sea at that town half-way between Beachy Head and Dover
cliffs. North and south of this ridge is the lower greensand, forming
in Sussex the low hills near Heathfield, Cuckfield and Petworth, and
which reaches the sea south and north of Hastings. It was at one time
supposed that the face of the Downs originally formed a white sea cliff
and that an arm of the sea stretched across what we know as the Weald,
but the simpler explanation is undoubtedly the correct one.

[Illustration: WANNOCK.]

The Downs themselves are composed of various qualities of chalk; some
of such a hard, smooth and workable material that, as will be seen
presently, the columns in some of the Downland churches are made from
this native "rock." While the upper strata is soft and contains great
quantities of flints, the middle layers are brittle and yield plenty of
fossils, lower still is the marl, a greyish chalk of great value in the
fertilization of the gault. This latter forms an enormous moist ditch
or gutter at the foot of the escarpment, and from the farmer's point of
view is essentially bad land, requiring many tons of marl to be mixed
with it before this most difficult of all clays becomes fertile.
Between the chalk and the gault clay is a very narrow band of upper
greensand, only occasionally noticeable in the southern range, but
strongly marked in the North Downs.

"The chalk is our landscape and our proper habitation. The chalk gave
us our first refuge in war by permitting those vast encampments on the
summits. The chalk filtered our drink for us and built up our strong
bones; it was the height from the slopes of which our villages,
standing in a clear air, could watch the sea or the plain