The Sun.
London, England, 1849-12-05 00:00:00

THE BRITANNIA BRIDGE.

MENAI STRA ITS.—TUESDAY APT ERNOON.—Every
precaution having been taken against a recurrence of
the contingency of yesterday, the transport of the
huge mass of tube, 472 feet long and 2,000 tons in
weight, was successfully effected to•day. During the
entire night large beacon fires were blazing on the
various platforms and on the shores cf the Straits, to
assist the workmen in Hatching and adjusting the
great network of floating apparatus. It is almost im-
possible, without actually being present, to realize an
adequate conception of the difficulty and hazsrd of the
operation, and of the iliad of implied contingency in-
volved in the safe launching, over a rapid tideway, of
a mass of material of such immense bulk.

No clue had been discovered to the suspected cut-
ting of the tackle yesterday, and it is asserted by the
Liverpool seamen to have been occasioned by the keel
of a large vessel from Carnarvon passing over the
cable on Saturday, the keel in question being cased
with iron, and consequently liable to cut.
From daylight until the hour at which operations
commenced crowds of people continued to wend their
way towards the works on either side of the Straits,
while upon their surface sailing and other boats found
it difficult, and, at many points, dangerous, owing to
the rocks and the rapids, to make headway through
the channel against a strong gale.
The pontoons and tackle that were to play the all-
important part in the great process were minutely,
examined at an early hour by Mr. Stephenson, Cap-
tain Claxton, and Mr. Clark, to ascertain that the
stay-braces, keelsons, bulkheads, tie-bars, caulkings,
and pumps, were all right. There were eight of them
ready to do duty, and take the 2,000 tons load upon
their backs, and bear it down the stream, six of
them of wood, and two of iron, their maximum
floatage power being 3,200 tons, each capable of sus-
taining 400 tons, and containing 19,000 cubic feet of
water, and of displacing a like volume when sub-
merged. Such is the amazing buoyancy of these
vessels that it is thought four of them would have
been sufficient to float the superimposed mass, but the
surplusage of disposable power was to enable those
who had the floating of the tube to adapt their arrange-
ments the more readily to the state of wind, and wave,
and weather. The displacement power of the pontoons
was equal to 2,400 tons. The subsidiary or control-
ling tackle, in the shape of cables and hawsers, were
extended over the Straits, and were two miles in
length, Lind 4 inches in diameter, attached to the
different capstans and on board the pontoons, where
the strain en them was enormous. These hawsers,
worked by the capstans, and by means of which, as
it were in leading strings, the tube was guided,
reached from the pontoons to the Anglesea shore,
kept afloat on the surface of the stream by
innumerable barrel buoys, and by means of which
the motion of the iron mass, governed by the play of
the capstans, was accelerated or retarded at the will
of the engineers. Each pontoon is 100 feet long, 25
feet wide, and 11 feet deep. The two iron ones are
of wrought iron' closely riveted together.. There are
large valves in the bottom of each pontoon, which are
kept constantly open, and in this state the tide has
entered them and left them daily without producing
any buoyant effect. A complete dock has been cut
out of the line of beach, which consists of schistus
or slate-rock, directly under the tube, so as to admit
of the entrance of the pontoons. The provision in
the pontoons of valves allowed the water to be ad •
mitted for sinking them the moment that the tube
touched the shelves. The depths of their sides and
flat bottoms gave them all the requisite buoyancy,
i with a comparatively small draught of water. By
capstans fitted on their decks, acting in contact with
-those on shore, the haulage of the tube was effected.
-Precisely at eleven o'clock, during a momentary
i snow-storm, but which in a few minutes was succeeded
by bright and brilliant sunshine, Mr. Stephenson,
Captain Claxton, Mr Edwin Clark, Mr. Brunel, Mr.
_Bidder, and Mr. Wild scaled the ladders that lEd to
the top of the stupendous tube, and gave the note of