National Republican. (Washington City (D.C.)) 1872-1888, 1875-03-01

works under whose direction the hrst roIied-iron
beams over nine inches deep that were ever made
were produced at these works.
The process Of rolling toughens the iron
seeming to draw out its hbres-and iron inst mas
been twice rolled Is considered Mt for ordinary
For the various parts of a bridge, however,
where great toughness and tensile strength are
necessary as Wen a' uni S o. ass tSsrs
fore cut again into pieces, piled, reheated and
rolled again. The uniformity Of texture and the
toughness OF the bars which have been thrice
rolled are so great that they may be twisted cold
into knot without showing any signs Of fracture.
The bars Of iron, whether hot or cold, are saIn
saws, which reYolvs with great rspidity.
For the columns intended TO sustain the com.
Presaive thrust Of heavy weights form Is used
In this Establishment Of their own design, and 70
which the name Of the "Phenix column" has
been given. They are tubes made from four or
from eight sections rolled IN the usual way anu
sary, such columns are Joined together BY cast
iron blocks, with circular lemons, which Mt into
To ioin two pars to resist . strain Of tension,
links or eye-bars are used from three TO six
inehts wide, and as long as may be needed AT
ceive pin. In this way any number Of bars can
be joined together, and the result OF numerous
experiments made at this establishment has
shown that under sufficient strain they will part
as OMEN in the body Of the bar as at the joint.
The heads upon these bars are made by pro-
cess known as die-forging. The bar is heated to
draulic pressure the head is shaped and the hole
struck at one operation.
This method OF joining by pins Is much more
reliable than welding. The pins are made Of
cold-rolled shafting, and 1T to q nicely.
In the machine shop, which covers several acres
Of ground, can be seen the various machines and
tools by which iron is planed, turned, drilled and
handled as though it were one of the softest ma
terials: Such machine shop is one Of the won
formed there, and all ofthe tools with which they
are done, are due entirely 70 modern invention,
many Of them within the last ten years. By
means Of this application of machines great accn-
racy Of work is obtained, and each part Of an iron
bridge can be exactly duplicated, IL necessary.
This method Of construction is entirely American,
the English still building their iron bridges
mostly with hand labor.
In consequence also Of this method Of working,
American iron bridges, despite the higher price
Of our iron, can
SUCCESSFULLY COMPETE
in Canada with bridges of English or Belgian
construction.
The American iron bridges are lighter than
those OF other nations but their absolute strength
is as great, since the weight which is saved is all
dead weight, and not necessary to the sOlidity Of
the structure. The same difference is displayed
here that is seen in cur carriages with their slen
der wheels, compared with the numbering, heavy
wagons Of European construction.
The method Of making all the parts Of bridge
to fit exactly, and securing the ties by pins, is
peculiarly American. The plan still followed in
Europe is that Of using rivets, which makes the
erection Of bridge take much more time, and
costs, consequently, much more. A riVeted lat
tice bridge one hundred and sixty feet in span
would require ten or twelve days for its erection,
while one of the PhRnixTille bridges Of this size
has been erected in eight and a half hours.
When iron was first used IN bridge construction
castiron was employed, but its brittleness and
unreliabilty have led to its rejection for the main
portions of bridges.
Experience has also led the best iron bridge
builders of America to quite generally employ
girders with parallel top and bottom members,
vertical posts Except at the ends, where they
made inclined towards the centre OF the span),
and tie rods inclined at nearly iortyfve degrees.
This form takes the least material for the required
strength.
The safety of a bridge depends quite as much
upon the design and proportions OF It's details and
which will compress or extend the ties, chords
and other parts can be calculated with mathemst-
But the strains coming upon the connections are
very often indetermnRte, and no mathematical
formula has yet been found for them. They are
like the strains which come upon the wheels,
axles and moving parts Of carriages, cars and ma
ehinery. Yet experience and Judgment have led
the best builders TO singular uniformity in their
an experiment, the lessons of which have been
studied and turned to the best effect.
Messrs. Clarke, Reeves & Co., the proprietors
= the PhUeniXyille Bridge Works, have enteTe
into contract with the Phoenix Iron Company,
PhenixVtlle, Pa, for long term Of years, BY
which the latter transfers to them all their iron
bridge-building, and orders for bridges and via
ducts are handed to them for execution.
By this arrangement the whole resources Of the
flUnl0 Iron company can De concentrated upon
the iulhllment OF their orders. Their present ia
cilities equal TO turning out one hundred feet
Of finished bridge for each toorkiHg day in the
year.
This firm are now building an iron bridge over
Anaeostia river at Washington, at tie site OF the
"Nayy-Yard BRIDGE" and we will conclude this
article with q
DESCRIPTION OF THE ANAcosTIA BRIDGE.
The bridge now being built over the Anaeostis
river, from Washington to UniontoWn, will be
each.
span Of 80 feet, and 40 feet Of causeWay, making
the total length Of bridge and causeWay 100
feet.
RE masonry for the piers and abutmeuts rests
on pile foundations. The piles are Of Georgia
white pine, from L to Is inches In diameter,
driven TO refusal under an OoPound hammer:
centre, and the tops are cut Oh at the bottom OF
the riyor to level, uniform surface. The ma
sonry is built in Water-tight eaissons, the Dot
toms Of which are formed Of one or two courses
OF square timbers II inches thick, and securely
bolted together. The ca!ssons are hoated into
built in them, on to the heads OF the piles. The
ends Of each pier and abutment are built Of
granite, the body Of Potomac blue gneiss. The
stones are laid in horizontal courses, with YER
teal joints and level beds, in hydraulic cement
mortar, the cement used being the iavorite. we'll
known brand called Round Top" There are Il
piers and abutments, on top Of which will be
placed the iron superstructure.
The bridge when finished will have one road
way 20 feet wide, and two sidewalks each i've
feet wide.
The trusses are similar In design to those Of
the new chain bridge over the Potomac river,
which was also built by Messrs. Clarke, Reeves
& Co. Each truss will be Is feet high. There
will be two Of them 10 each span, placed % feet
apart from centre to centre. The spans Will be
separate and independent Of each other, and will
rest upon cast-iron brtdge-seats, securely an
ehored to the granite copings.
Each span will be divided into seven panels OF
"A feet each: The upper chords main and inter,
iron. The lower chords and main ties will be
formed Of dieforged links without Yields.
The main and intermediate posts and the upper
chords will be fitted to cast iron caps and seats,
all points Of bearing being truly turned or planed
to perfect 1T. Turned Wrought-iron pins will
lock in one connection the caps Of the columns
and the diagonal ties; also the bottom chords and
column-seats, diagonal ties and ioor-beam sus-
pendeTs.
weighing 2c0 pounds per yard.
The sizes OF the iron throughout the bridge
will be such that II the entire structure be loaded
with q weight Of 100 pounds for each and every
square foot Of surface, the maximum strain pro-
duced thereby will not be greater than one-sixth
OF the ultimate strength Of the bridge.
All parts Of the superstructure will be Of
wrought iron, Except upper chord-connections and
postfeet which will be Of cast iron) Of the brand
known in the market as phoenix Best-Best."
The draW.span will be what Is known as q
'hinge.draw,n and will be so counterbalanced by
weights that but very little and q uniform power
will be required to operate It. II will be lifted
with proper gearing SO as to be readily opened or
closed by one man.
Tho sidewalks will have ornamental wrought
iron hand rails, we'll and securely fastened to the
iron floor beams.
At each end Of the bridge ornamental iron por.
tails will be placed, and the entire structure will
be neatly painted with three coats Of paint.
The causeWay approaches will be made of clay,
protected on their outer slopes with rubble ma
sOnry. The roadway over them will be macada-
mixed with small broken stone eighteen inches
in depth; the curbing will be six-ineh granite or
North river bluestOne, and the sidewalks Will be
paved with red bricks.
Messrs Clarke, Reeves & Company are under
bonds to the United States 70 complete the entire
structure by the first day of next July.
At the present time about one third Of the ma
sorry is built, and all OF the iron Is finished and
Is at Phenixville ready to ship as soon as nayi-
cation opens. 1t is confidently expected that the
whole Will be finished by the hrst OF May.
Treating the Wrong Disease.
Many times women call upon their family ply
sieIans one with dyspepsia, another with palpita-
ton, another with trouble in the breast, another
with pain here and there, and In this way they all