nd accessible for the largest
vessels, and the Helford river. On the north are the estuaries of the
Camel and the Hayle, debouching into Padstow Bay and St Ives Bay
respectively. The Fowey and Camel valleys almost completely break the
continuation of the central high ground, and the uplands west of Mount's
Bay are similarly parted from the main mass by the low tract between
Hayle and Marazion. Except at the mouth of a stream or estuary the coast
is almost wholly rock-bound, and the cliff scenery is unsurpassed in
England. Three different types are found. On the north coast, from
Tintagel Head and Boscastle northward to Hartland Point in Devonshire,
the dark slate cliffs, with their narrow and distorted strata, are
remarkably rugged of outline, owing to the ease with which the waves
fret the loosely-bound rock. On the south, in the beautiful little bays
in the neighbourhood of the Lizard Point, the serpentine rock is noted
for its exquisite colouring. Between Treryn and Land's End, at the
south-west, a majestic barrier of granite is presented to the sea. The
beautiful Scilly Isles continue the line of the granite, and the
intervening sea is said to have submerged a tract of land named
Lyonesse, containing, according to tradition, 140 parish churches, and
intimately connected with the Arthurian romances.

_Geology._--One of the most striking features of Cornwall is the
presence of the four great masses of granite which rise up and form as
many elevated areas out of a lower-lying region occupied by rocks
almost entirely slaty in character, generally known as "Killas." The
granite is not the oldest of the Cornish rocks; these are found in the
Lizard peninsula and are represented by serpentine, gabbro and
metamorphic schists. With the exception of a small tract about Veryan
and Gorran, of Ordovician age, all the sedimentary rocks, as far as a
line joining Boscastle and South Petherwin, were formerly classed as
Devonian; to the north of the line are the Culm measures--slates,
grits and limestones--of Carboniferous age. The extensive spread of
Killas is not, however, entirely Devonian, as it is shown on most
maps. In the northern portion, Lower, Middle and Upper Devonian can be
distinguished; the lower beds at Polperro, Looe and Watergate, the
higher beds along the line indicated above. Farther south it has been
shown that an older set of Palaeozoic rocks constitutes at least a
part of the Kil