remtiy unchanged, and though occasionally ' slices of cliff do fall
away, such instances are rare, at long interval«, and scarcely ever
known by any one person to happen at the same spot. At the
present time progressive rates of three inches and on* inch per
year are certainly too great, but we may fairly take such «uà average,
because the horizontal a’dvance of the sea would lessen each vow as
the vertical depth of thè cliff to be removed increased.
The Island is now bounded by a coast line of 30 miles. Its superficial
area measures 45 square miles,',or 28,800 acres. A careful
calculation estimates, the entire encroachment of the,sea at 30 square
miles, or 92,928,000 square yards, while no less than 11,587,280,000
cubic yards of solid land have been removed through its denuding
power. Now assuming, from our previous calculation, the Island to
have existed only 40,000 years, ,we have an annual encroachment of
the sea un the tawd ?' % 2? square yards, and a yearly removal by
demid.it ' - j? ■ - ,n, us mass it®,682 cubic yards.' The
nines wiìieb ju t ©ut around the windNvard coast from
Turi » t.iip to Man and Morse show this mxkm of the sea, especially
at a place called “Lot’s Wifi* jPostdR," where a fine illustration
of fhis terribly destructive agency is seen in the ruins of many
dikes, which the devastating power of the waves has brought down
to their own level. They have all the appearance of regularly built
jetties running out through the surf into the sea. I t would be difficult,
however, to land at the spot, as they cross each other and lie in
almost every direction just below the surface of the water. A portion
of one of the hardest, a very dense block of black basaltic rock, has
long defied the force of the water, and stands in a striking position,
about twenty feet away from the mainland. I t measures about fifty
feet in height, thirty in width, and from four to six in depth, and
from its remarkable appearance bears the name of “ The Chimney.”
Several small islets, some of which stand sufficiently away from
the coast to allow a ship of large size to pass between, also testify to
this destructive action of the sea. Both Egg Island and George’s
Island show the same formation of lava beds as the adjacent coast,
while Speery Island marks a portion of the great -Lot dike, and
Peaked, or Lanark, Island is a curious remnant of a «coriaceous mass
of cinders firmly cemented together, the counterpart of wbsA ... seen
in & thick bed of rubbish on the mainland oIp prosite'.
A t-a time when the plains of Rupert’s Hill, Hollow,