alue of
Portland Harbor is chiefly due, and many are the theories to account for
its formation. Near the estuary of the Fleet is Abbotsbury, where are
the ruins of an ancient church and the Earl of Ilchester's famous
swannery, where he has twelve hundred swans.

[Illustration: PORTLAND ISLE.]

The Isle of Portland, thus strangely linked to the mainland, is an
elevated limestone plateau guarded on all sides by steep cliffs and
about nine miles in circumference. Not far from the end of the Chesil
Bank is Portland Castle, another coast-defence erected by Henry VIII.
Near by, on the western slope, is the village of Chesilton. The highest
part of the isle is Verne Hill, four hundred and ninety-five feet high,
where there is a strong fort with casemated barracks that can
accommodate three thousand men. Other works also defend the island,
which is regarded of great strategic importance, and in the neighborhood
are the famous quarries whence the Portland stone has been excavated for
two centuries. The most esteemed is the hard, pale, cream-colored
oolite, which was introduced to the notice of London by Inigo Jones,
and has been popular ever since. With it have been built St. Paul's
Cathedral, Somerset House, the towers of Westminster Abbey, and
Whitehall, with other London buildings. Here also was quarried the stone
for the great breakwater, of which the late Prince Consort deposited the
first stone in 1849, and the Prince of Wales the last one in 1872,
making the largest artificial harbor in the world. The first portion of
this breakwater runs east from the shore eighteen hundred feet. There is
an opening four hundred feet wide, and the outer breakwater thence
extends north-east six thousand feet, terminated by a strong circular
fort guarding the harbor entrance. It cost over $5,000,000, and about
one thousand convicts were employed in its construction, which took
nearly six million tons of stone. The materials, quarried and laden on
cars by the convicts, were sent down an inclined plane and out to the
appointed place, where they were emptied into the sea. The prison of the
convicts is on the east side of the island adjoining the quarries, and
is almost a town of itself, having twenty-five hundred inmates. The
prison-garb is blue and white stripes in summer, and a brownish-gray
jacket and oilskin cap in winter. The convicts have built their own
chapels and schools, and on the Cove of Church Hope near by are the
ruins of Bow