The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1867-08-22
Three Great Works.

counts OF four great works In the Unlted
States, which are worthy Of particular
notice. They mark this age Of enterprise
and intrepid engineering. The first in or
der we present as western Improvement,
and hardly second to anything yet under
taken in the Union. This great work is
THE ST. LOUIS BRIDGE.
This vast undertaking has been inaugu-
rated under the most favorable auspices,
and will be great triumph Of art and en-
tcrpriSo. This bridge is to be built across
the Mississippi from the Illinois shore to
St. Louis. 1t has become absolutely ne
ceSsary to accommodate the vast and con-
stantly increasing continental trade. 1t
will be about three-tenths of mile or
l,509 feet in length. Tho wonder of this
great undertaking is in the difficulties met
with in the constantly shifting sands Of
the Mississippi river, and their great depth.
The bridge has to be Of great elevation to
avoid the obstruction Of navigation and
for the same reason, and the additional one
Of the difficulty and expense Of getting
proper foundations, the spans are very
long.
1t is to be pier bridge, resting on solid
stone foundations, on which will rest
arches of steel sustaining the spans.
These arches will surpass anything Of the
kind ever erected. The two side spans
will be four hundred and ninety-seven
feet each in length, and the central span
five hundred aud fifteen feet in the clear,
between the abutments. Ordinarily there
will be from sixty to seventy feet distance
between the lower side Of the central span
and tie water, and fifty feet in time of
high water. 1t may be said here that the
boats from below st. Louis rarely go
above, and rtce uerSa, so that there need
he litte.passage under the bridge. There
will be tracks for both carriages and rail-
way cars. The railway track on the st.
Louis side will pass over the first street,
and then 60 under ground for about three
quarters of a mile under the central part
of the city, when it will emerge at the
grounds selected for great union passcn-
ger depot. The stone arches on each side
OF the bridge are expected to add much
to its architectural effect. 1t is said that
in general style and character it will re-
semble the celebrated bridge over the
Rhine at Coblentz.
The most difficult part of the problem of
building this bridge will be the putting
down of the piers, which will be very mas
sive. They are to be 100 by SO feet at the
bottom, and about 10 by 80 feet at the top.
The river bottom is composed of shifting
sands, below which is found the solid rock
bed on which the piers must rest. The
sand to he gone through varies from 80 to
so feet in thickness, so that one Of the CEN
trail piers descends through water and sand
for over 10 feet, and the other for nearly
100 feet. To add to the difficulties of con-
struction, this work must be done between
the periods Of food and ice, SO that the
piers may be raised far enough above wa
ter to avoid injury while unfinished.
The cost of the bridge and tunnel is esti-
mated at S., 100000. the land used will
probably cost a750,000 more. 1t is sthought
that the bridge will be completed in three
years-iust about the time when the Allan
tic and the Pacific will be joined forever
by the iron rails.
EAST RIVER BRIDGE.
This is to be suspension bridge, and
will excel in many respects any bridge in
the world. 1t will connect New York and
Brooklyn. 1t will probably cost SG,000,000,
and the company which builds it must
have capital of nearly sS,000,000 to
cover land damages, etc. 1t will take five
or six years to complete it. The laying
of the foundations will take about one year.
The Brooklyn entrance to the bridge
will be at the intersection Of Sands and
Fulton streets the New York entrance at
the City Hall Park opposite the Registers
office. This will make the whole length
of the bridge 5,SG2 feet-one mile and SOP
feet. The grade will be three feet in 100.
From the entrance on either side for the
length of 500 feet the width will be 100
feet. 1t then contracts to so feet, which
will be the width Of the bridge proper.
The added width of 20 feet in the 500 will
be for walks, to regulate the movements of
passengers moving in opposite directions.
The bridge will be divided into two road
ways of Is feet each-one for "going "
and the other for "coming." There are
two other divisions of 30 feet each that
will comprise railroad tracks for the run
ming of passenger cars by wire ropes.
Two trains Of passenger cars, capable OF
transporting 1000 passengers each way
simultaneously, make trips every live
minutes. Three minutes will be taken up
with the running of the trains-the other
two for exit and entrance OF passengers
into and from the cars. Entrance to the
cars through side doors.
A fifth division of the bridge will form
promenade of sixteen feet IN width, eleva-
ted so that promenaders can overlook the
four divisions beneath as well as the ADA
cent territory and water.
The most conspicuous part OF the bridge
will be the two towers, located at the dls-
tance of 1000 feet from centre to centre.
The height Of these towers will be loO
feet above the roadway. Investigations or
the ground for anchoring the great wire
ropes are being made. 1t is proposed to
utilize all tho ground on both SIDES lne
river over which the general bridge passes
by making stores and warehouses. Ihls
great work is under the direction of Mr..
Roeblng, an engineer of great reputation
and much experience in constructing sus-
pension bridges.
This capacious highway will afford much
relief to the city Of New York, SO OPP
as it is with masses OF human
beings, especially in the vicinity OF tne
PARK. where such multitudes and SO many
hundreds of vehicles are ever congregaIlns
towards the main points Of divergence TO
the Brooklyn and other ferries.
HARLAEM BRIDGE.
This bridge, over the Harlaem river, IS
nearly complete. 1t does not compare
with those above named, but is, neverthe-
less, a work of considerable magnitude,
and will cost over million of dollars. Ii
connects the island Of Manhattan -
now almost entirely occupied by the city