combinations, we dare not venture, nor into their
relative merits. Of the comparative practical
advantages of the two great systems, we
shall merely say that the dioptric system
provides a light four times more powerful; while
the catoptric system insures a more certain
exhibition of the light. The accidental
extinction of one of the lamps in the catoptric
light, leaves only a fraction of the horizon
without light; whereas the extinction of the
one great lamp of the dioptric light, deprives
the whole horizon of light. Nevertheless,
when the great rarity of such an accident as
the extinction of this one great lamp is
considered, together with its far greater economy
in oil (being above one hundred and forty
pounds a-year less than the other system of
lighting), with some further advantages, the
preference is generally given by lighthouse
opticians to the dioptric system.

It is obvious that the method of furnishing
light to the light-boats, or floating-lights,
must be a simpler process than those which
have just been described. The term
"lantern " is appropriate enough here; since
the apparatus does actually consist of a large
octagonal lantern of copper framework and
plate-glass, protected outside by some wire-
work, and fixed at a mast-head. They are
fitted with eight argand lamps, and parabolic
reflectors. A very strange appearance these
boats present, of which the heavy, Indian-red,
floating strong-box, with an onion gone to
seed sticking out of the lid, and called the
"Nore," may be considered as a first-rate
specimen. These light-boats are of the greatest
service; in fact they are obviously indispenable
to safe navigation.

There are various positions of danger which
are beyond the reach of lighthouses.
Sandbanks, for instance, where the erection of any
solid structure is impossible, are often the
sites for mooring light-boats. The annual
expense of maintaining a light-boat, including
the wages and victualling of the crew, eleven
in number, is, on an average, one thousand
pounds; and the first cost of such a vessel,
fitted completely with lighting apparatus,
mushroom-anchors, cables, &c., is nearly five
thousand pounds.

Many interesting particulars belong to
the building of lighthouses. Events occur,
which are not only as exciting as they are
arduous and interesting, but which cannot
occur to any other kind of erections,—even to
the very disheartening circumstance of a
rough stormy night sometimes sweeping away
a whole twelvemonth's, perhaps years, of
constant labour and hardship. The narratives of
several of these are among our most interesting
nautical records.

For architectural grandeur, Mr. Alan
Stevenson declares the Tour de Corduan
to be the noblest edifice of the kind in the
world. It is situated on an extensive reef at
the mouth of the river Garonne, and serves
as a guide to the shipping of Bordeaux and
the Languedoc Canal, and indeed to all that
part of the Bay of Biscay. It was founded
in the year 1584, but was not completed till
1610, under Henri Qiiatre. The building
is one hundred and ninety-seven feet in height,
and consists of a pile of masonry, forming
successive galleries, enriched with pilasters
and friezes, and rising above each other
with gradually diminished diameters. These
galleries are surmounted by a conical tower,
which terminates in the lantern. Bound the
base is a wall of circumvallation, in which
the light-keeper's apartments are formed; the
wall serving also as an outwork of defence
by receiving the first shock of the waves.
The tower itself contains a chapel, and
various apartments, and the ascent is by a
spacious staircase.

The first light exhibited in the Tour de
Corduan was obtained by burning billets of
oak wood in a chamber at the top of the
tower. A rude reflector, in the form of an
inverted cone, was afterwards added to
prevent the loss of light which escaped upwards.
About the year 1780 M. Lenoir was employed
to substitute paraboloïdal reflectors and
lamps; and in 1822 the " light " received its
last improvement by the introduction of the
dioptric instruments of Augustin Fresnel.

Smeaton's Narrative of the Lighthouse on
the Eddystone Rocks is full of interest.
These rocks are upwards of nine miles
distance from the Ram-Head on the coast of
Cornwall; and from the small extent of the
surface of the chief rock, and its exposed
situation, the construction of the lighthouse
was a work of the greatest difficulty. The
first erection was of timber: it was designed
by Winstanley, and commenced in 1696. It
was soon found, however, that the sea rose
to a much greater height than had been
anticipated; so much so, it is said, as to bury
under water the lantern, though this was
sixty feet above the rock. Winstanley was,
therefore, under the necessity of enlarging
the tower and carrying it to a greater height.
He raised it to one hundred and twenty feet,
which was too high for its strength to bear.
In November, 1703, considerable injury had
been received, and Winstanley went there in
person, accompanied by his workmen, and
proceeded to institute the repairs. On the
26th of that month, a storm arose, so violent,
that it carried away the whole edifice, with
poor Winstanley and all his workmen, every
one of whom perished.

The loss of this " light " speedily led to a
yet more numerous loss of lives. The
"Winchelsea " man-of-war was wrecked on the
Eddystone Rocks, and nearly all her crew
perished. Three years were allowed to
elapse after this melancholy and unanswerable
evidence of the necessity for a " light," before
the Trinity House could obtain a new act of
Parliament to extend their powers (so writes
Alan Stevenson); but whether the delay
rested most with the Government or the