s, the towns of Lydd and Romney
being the only parts of the marsh above the level of the highest
tides.[419] Mr. Redman has cited numerous old charts and trustworthy
authorities to prove that the average annual increase of the promontory
of shingle called Dungeness amounted for two centuries, previous to
1844, to nearly six yards. Its progress, however, has fluctuated during
that period; for between 1689 and 1794, a term of 105 years, the rate
was as much as 8-1/4 yards per annum.[420] It is ascertained that the
shingle is derived from the westward. Whether the pebbles are stopped by
the meeting of the tide from the north flowing through the Straits of
Dover, with that which comes up the Channel from the west, as was
formerly held, or by the check given to the tidal current by the waters
of the Rother, as some maintain, is still a disputed question.

Rye, situated to the south of Romney Marsh, was once destroyed by the
sea, but it is now two miles distant from it. The neighboring town of
Winchelsea was destroyed in the reign of Edward I., the mouth of the
Rother stopped up, and the river diverted into another channel. In its
old bed, an ancient vessel, apparently a Dutch merchantman, was found
about the year 1824. It was built entirely of oak, and much
blackened.[421] Large quantities of hazel-nuts, peat, and wood are found
in digging in Romney Marsh.

_South coast of England._--Westward of Hastings, or of St. Leonard's,
the shore line has been giving way as far as Pevensey Bay, where
formerly there existed a haven now entirely blocked up by shingle. The
degradation has equalled for a series of years seven feet per annum in
some places, and several martello towers had in consequence, before
1851, been removed by the Ordnance.[422] At the promontory of Beachy
Head a mass of chalk, three hundred feet in length, and from seventy to
eighty in breadth, fell in the year 1813 with a tremendous crash; and
similar slips have since been frequent.[423]

About a mile to the west of the town of Newhaven, the remains of an
ancient intrenchment are seen on the brow of Castle Hill. This
earth-work, supposed to be Roman, was evidently once of considerable
extent and of an oval form, but the greater part has been cut away by
the sea. The cliffs, which are undermined here, are high; more than one
hundred feet of chalk being covered by tertiary clay and sand, from
sixty to seventy feet in thickness. In a few centuries the last vestiges