The Empire County argus., 1855-08-25
The Suspension Bridge a, Niagara Falls.

The Buffalo Democracy gives very interesting
description ot that magnificent triumph of art the
suspension bridge which carries the Great Western
Railroad across the Niagara river. and so connects
the United States with Canada. 1t speaks of it ss
the proud and enduring monument of the engineer
MI }. Roebling We were aware that the
bridge had the tremendous span of upwards of
eight hundred feet and that it stands two hundred
and forty-f feet above the food that no man has
been able to ferry. but we We're scarcely prepared
to lind that the structure is Of such majestic
strength as it appears to be. The def. elton in the
middle when loaded with freight train, is only ten
inches.
Delicate rs lace work and seemingly light and
airy. it hangs there between Heaven and the boil
ing flood below. more solid than the earth bed of
the adjacent railways. The conclusions of fast
moving trains are sensibly felt miles off through
solid rocky soil. In cities locomotives shake entire
blocks of stone dwellings. The waters of the Ca
yuga Lake tremble under the wheels Of the express
rains u mile away from the bridge But freight
train traversing John A Reebling's monument at
the speed of five miles an hour communicates no
jar to passengers walking on the carriage way be-
low. he land cables of the bridge do not lrem-
u under 1.-THE slight conclusions of the super
st cure do not 60 over tie SUBMITS of the towers
ne last fact, in the stiffness Of the great work is
"t much Importance. 1t furnishes guaranty of
the durabi of the masonry. Fast anchored with
stone, and grouted in solid rock cnt down to the
depth Ut 25 feet. the great cables are immovable
by any mechanical force incidental to the Use of
the bridge or the natural influences it will be sub
ject to. The Ultimate strength Of these cables is
l2oOO tons, The total weight Of the material OF
the bridge and Of the traffic to which it will ordi-
narily be subjected is 2262 tons to sustain which
the engnet has pro>i led il his beau u and sci.
entihc structure, strength Of 1900 tons He
demonstrates. too that while the strength of the
cables is nearly six times great as their ordinary
str moth L. ;p,po ,rn1 1,
vibration.
There are in the bridge 624 suspenders, each ca
pabe of sustaining 80 tons--and all of sustaining
Is 72O tons. The weight they have ordinarily to
support is only 1000 tons. But the engineer has
>kllltuly distributed the weight of the burdens bv
the means of girders and trusses. These spread
the "a tons weight of locomotive and tender over
length of 200 feet. How ample is this provision
made for defective iron or sudden strains
he anchor chains are composed of nine links.
each seven feet long, save the last, which is ten
feet. he lowest link is made OF seven bars of
IRON, Ixl@ 1t is secured to a cast-iron anchor
plate 81 inches thick and 6H feet square The
ther links are equally strong. The iron used was
all made from iennoy vania charcoal, Ulster coun.
ty, n. Y, and Salisbury pig, and can be depended
on for a strength of "a 900 pounds to the square
inch. The central portions of the anchor plates
through which the links pass is II inches thick
he excavations in the solid rock were not vertical
they inclined from the river. The rock upon which
the work may rely upon the New York side of the
chasm is 100 teet long. 10 feet wide and 90 feet
deep. 1t weighs lGO pounds TO the cubic foot, and
presents resistance of l4.0O0 TONS exclusive of
the weight Of the superintendent masonry and
enhancement.
he towers each Is feet square at the base
W feet high above the arch and feet square nj
the top. The limestone of which they are built
will support pressure Of 500 tons on each square
foot without crushing. While the greatest weight
that can fail upon the tower will rarely exceed zoe
tons pressure OF $4,000 would he required to crush
the top course. There are 1000 tons weight III
each Of the towers on the n. York side.
The cables are in number. 10 inches in diame-
ter, and composed each of 3.640 small No 9 wires
Sixty wires form one square inch Of solid section
making the solid section of the entire cable 60 40
square inches, wrapping not included These i'm
hense masses OF wire are put together that each
individual wire performs its duty and in q strain
all W. r6 togt ther
Among the interesting characteristics Of this
splendid architecture is its elasticity. The depres-
sion under load commences at the end. of Course.
and goes rapidly across. After the passage of
rain the equilibrium is perfectly rest, red The
Elasticity Of the cables is fully equal to this task
and will never he lost.
The equilibrium of the bridge is less affected in
cold weather than IN warm. If change of tenn
perature of 100 deg should take place, the differ
tHCc III tHS lcNel VI uOUr NOulu Ue Ietl
inches
So solid is this bridge in its weight, its stiffness
and staying that not the slightest motion is com.
municated to it by the severest gales of wind that
bl,,w up through the narrow gorge which it spans
Next to violent winds, suspension bridge builders
dread the trotng of cattle across their structures.
Mr.. Roeblng says that heavy train running 20
miles an hour across his bridge would do less injury
TO it than would 90 steers passing trot. 1t is
the severest test next to that of troops marching
in time, to which bridges-iron wooden. suspen-
sion or tubularcan be subjected. Strict regula-
tions enforced for the passage of hogs horses
and oxen, in small bodies and always on a walk
This great work cost only 100000. The same
structure in England (if it cuuld possibly have
been built there) would have cost S4,09O0O0 1t
is, unqu4stonably, the most admirable work Of art
on this continent, and will make an mperishable
monument to the memory of its engineer, John "A.
Roebling.
The tubular bridge huilt by Robert Stephenson
over the Menai Straits, for the Chester and Holy
head railroad in England, cost the company mil
lion sterling.
A writer for religious paper, speaking of the
chanticleer and the eagle on the spires of church