Prescott journal. [volume] (Prescott, Wis.) 1861-1871, 1869-12-23
A HUGE BRIDGE.
The Proposition to Wed England and
.France--Some of the Features OF the
Plan.

Now that the Pacific Railroad and the
Atlantic cable, once considered impossi-
bic, are in successful operation, various
writer's and engineers are specializing as
to the best means of accomplishing the
impossible in other directions. In Ap-
pleton's Journal for December 4, details
are given of the latest of these specula.
tons, in an article on an international
bridge between England aud France.
Concerning the proposition to build such
a bridge, which the writer characterzes
as the "most novel, curious, and ven
turesome proposition ever seriously en-
tcrtained," he says:
"The continuous passage of this arm
of the sea has been long discussed, and
device after device has been suggested,
but after mature reflection. all have been
laid aside as impracticable. AT last,
however, a scheme has been ripened
which seems to offer so mary guarantees
of feasibility, that the British and French
governments unite in giving it serious
attentions. Among the objections 10 for
mer projects were the enormous relative
cost and the inadequacy of the mechan-
ism. With regard to tunneling. any one
who recalls what he has read concerning
the fearful labors and expenses of the
Thames tunnel, will readily understand
why that idea was quickly abandoned, in
connection with deep sea bed more
than twenty miles in width. ua
The French engineer Boutet has final
ly hit upon system that promises to
| conquer all difficulties. He has devoted
years to the labor of experiment and ex-
animation, and has succeeded in getting
together joint stock company, consist
ing of some of the first engineers and
manufacturers in the north of France.
Tbs company has caused a model, one
hundred feet in length, with all appliances
and paraphernalia, to be constructed,
end with this they explain their project,
and execute their experimental trials.
"Boutet has really two projects to pro-
pose, the FIRST of which contemplates a
bridge with single span. The second
has in view bridge of ten spans, each of
the latter nearly two miles in length. The
latter system is the one preferred, chiefly
because it is the more economical of the
two schemes. The proposition is to have
the bridge rest upon the Shakespeare cliff
on the English, and upon Cape Blanc
Nez on the French side. These two
promontores, which arc of solid chalk,
offer sufficient resistance to sustain tbs
whole weight of the structure. The ex-
act distance between these two main abut
ments is 29,700 meters, equal to 3l5 feet
less than Is Q miles, to which must be
added 492 feet more for the escarpment
on both sides.
Each span will consist Of five vertical
frames or tressels. all five firmly fastened
together, SO as practically to form but
one, presenting the appearance of net
work of KS. Upon this tressel work
will be laid the flooring of the bridge,
upon which will be placed the various
tracks, roadbeds, footpaths, etc., the safe
ty of passengers being secured BY para
pets. Near the escarpment the platform
or tresse of tho bridge will be go feet
in verticle dimensions, and suspended So
feet above the surface Of tho sea. The
construction will be such that at every
point lightness and solidity will be com
bined in the most judicious manner, aud
the weight equally distributed. The
strength of the bridge will allow II full
trains, laden to their utmost capacity, to
cross the axis of the spans in safety at the
same time, were they TO meet, and had
tracks enough 10 pass. The breadth Of
the bridge multiplied by its own weight
gives resistance SO times greater than
the force of the strongest gale beating on
such surface.
So far as the plan has been disclosed
to the public, the new idea consists in
constructing the pillars of iron, and
heavy timber tressel work in dock yards,
or other suitable places on shore, so that,
by the aid of buoys fastened below them,
and removable when they have veen Sc
cured at the proper point, they can be
towed to their places aud there lowered
to the bed Of the sea. These places are
TO be previously ascertained and marked
by floating buoys, all attached to one
cable, which is to extend, like builders
line on land, across the straits.
"The base of the pillar, which will
consist of open work, in order to offer
the less resistance to the tide and current,
will be extremely firm and strong, and
at the same time have tue elasticity of
spring, from the popularity of its con-
struction. The part most exposed to
the beating of the waves will be boxed
in solidly, and protected by an armor OF
interviewer galvanized iron work. The
upper part, on which the burden of ne
superstructure will Immediately rest, will
lie open, in order to oppose the smallest
possible aggregate of surface to the
winds, and will afford easy access for
alteration or repair, and at the same
time will not obstruct the view of mari
ners, as solid pillars would necessarily
do. The method of securing the pillars
on the bottom is not disclosed, but en-.
gineers will readily understand that an
chofs and braces supply oil necessary
means for that purpose. The towing
and sinking of tho pillars present the