Pullman herald. [volume] (Pullman, W.T. [Wash.]) 1888-1989, 1890-03-01
SUSPENSION BRIDGES.
How an Edinburgh Professor Illustrated
Their Utility.

Their Utility.
For centuries suspension bridges have
been built, sometimes of chains, some
times of ropes, these latter often
made from the bark of trees; although
iron suspensions are of comparatively
recent times. One of the highest en-
cheering authorities of the United
States thus briefly states that 1.-The
economy of metal in a suspension bridge,
under the average circumstances of its
attainable depth, is from one-fourth to
one-half of that in tubular or simple
girder-bridge of equal strength and
rigidity." The simple rope bridges in
Peru and in Central Asia are merely two
ropes hung side by side across some
space sought to be spanned; then a kind
of platform is laid on these ropes, and
the inverted bow or dip is such that
man or beast may cross. The suspen-
sion bridge, as we have it, is composed
of two or more chains, and from these
chains a level platform is hung by sus-
pension rods; the chains are generally
secured to either side of the chasm
crossed by what is known as anchor
age, by passing over piers. The chains
used to construct these suspension
bridges are wire ropes or chains COM
posed of links. AS already intimated,
the cost of the suspension bridge is
much less than that of many other kinds
of large bridges, because of the amount
of material required. The late Prof
Jenkin, of the University of Edinburgh,
thus clearly illustrates this: A man
might cross a chasm of 100 feet hanging
to steel wire OIL inches in diameter
dipping 10 feet the weight of the wire
would be II. IS pounds. A wrought-iron
beam of rectangular section, three times
as deep as it is broad, would have to be
about 81 inches deep and inches broad
to carry him and its own weight. 1t
would weigh 81, 500 pounds" Trains do
not as rule cross suspension bridges at
a high rate of speed, and unless other
wise strongly fastened so as to over
come lateral and other oscillation, the
dangers are considerable. Engineers
have, however, so thoroughly studied
these and all other matters in connec-
ton with bridge-building that these
great structures are now made with
view of meeting all such strains and
contingencies. Some of the best-knOwn
suspension bridges in the world have
been the Brooklyn bridge, the bridge
over the Ohio at Cincinnati, the Sus-
pension at Niagara, the chain suspen-
sion at Menai Strait, at Fribourg,
Switzerland, and at Pesth over the Dam
ube.-Chicago Inter Ocean.
In York County, Pa, party of
tramps recently emptied water tank
and converted it into bedroom
The American Bible Society reports
that Bible distribution was 80 per cent.
larger last year in South America than
during any preceding year. The num-
Der of Bibles, New Testaments or parts
disposed of was 81, so2. During the past
ten years 264. 542 copies have been cir
culated, of which 80. 4S4 belong to the
first half of the decade and ia 05S to the
last half: These figures are exclusive
of the work of the Valparaiso Chilli BIZ
BILE Society which sold during the past
year 4 563 copies and during its exist
ence of twenty-eight years has distribut-
ed 81, AZ copies in the republic of Chill.