New-York daily tribune., 1858-08-17
TIE VICTORIA BRIDGE.


F,on ne Ho.syse! I,GsteriJf, A.s. IL
T.,xo,k forrbe construction of :.is noble ectceis
TOW rspidly proceeding. and Ts lad 50 opp'Nuniy
few d.ys sgo OF eIsulIlrg not orlY me conPISe-
part, cf the structure bat also tis o2ef3o1s Nn'n
are taking place ICE dams sd pe-s ESca s'e 10.
ys, snl.hsd We fret proceeded over he souims9'
IN the uo,td shore 20 the t15es Fhlch are aliesoJ
placed scrcs. the two ffst spsns Of the bridge. hs
work Of TIE riytSy of .1e plates ss gong on aa e
structure rspg vItr the clsrgor q MANNERS i9iMLs
~. he sds OF the b0lfs isrge NUMBER OF portsoi7
torres were stationed ell pats CT the tn,e' s,o oo
The top Of il: ard Ive;s heated u TIE hrss were up
pied 70 me woIk1en by boys a:.sneg on e.c9 i''ss
In is Interesting 20 the sp.sd Win Thcn ron
m.terisl hardy kroTa few years SGD n tie
ars Of cor corstr1cti0u-csn b. formed lr.o edi'
fees adapted 10 tie purposes OF msn. LIS
speed s much facilitated by tne clFc1hsanSS
ia. all the Darts Of ,le iubes are mIltiph.
cations OF the sane patterns. Tae bridge VIII
cor set OF twenty -four PIERS with twenty-five opeo
rgs or spsLsthe center about pst "a srge sg sn aS
the others These openings are covered oy taoe, o,
rather by series Of .abes Of boiler plate, sepa'sed
from each other al the ends, snd Strengthened oy an
gle ilOn An article ike ms ls not tos place ioI an
account OF the which make the tuou!sr TORN
OF materials stronger than sny ot1eI arrangement oI
th,m; bu, We msy rsmsrk that If tne tour pia,es
which form the four sides Of the tube were laid one
upon sno.her, t5e thickress of Ihe waoe would not
exceed about two and half inches, sud would Dot
suprort fitch part of the losd which sy oe ss.e'
" csnisd over the tubes. II needs engineering
nor Mechanical knovedgs TO be able 20 understand
that hsrdly any accumulated tbicknesses OF such
material laid il fat shape over an operlns between
2CO feet and 800 feet vice would support the hua'
drsos Of tons weight made up by tie component parts
of a railway train resting on tae middle OF u.
The plstes throughout the tubes are double; ooltsd
10 epge iron beams and guters; end aways overlsp-
ping each other al the e1ds tor iurtaer security
each Joint has placed over IL, on esch side OF the
plates extra sheet boed both sides OF the pint
ard called covering plate. The object Of sl these
precautions is 10 make the tubes resemble as mucl a.
-. 4vbog do avpr nj ne
Mspy very delicate considerations have 20 be at
tended 70 by the engineer who adopts tbs tubular
mode Of construction IN order 10 give his roadway
the greatest strength, with the least weight aud cost
The cCndiiiCn upon which TIE attachments OF this end
depends is that the relative strain upon each inch OF
the turitce should be known and the strength OF tne
metal a. that place proportional to the stress 10 Is
impossible here 10 give any idea OF the da'a upon
which these calculations are made. The result how.
ever is tb6t the hardest duty must be done by the
metal situsted at the ends Of he tubes and accord
nsly this part il strengthened by considerable add
un 10 the ordinary number II transverse supports Oi
angle IRON Ato the plates themselves, the ane kind
OF calculations have determined that those IN the bot
tom and top of the tube should be hnnest at the end
and tbickest in the middle of the length, while this
order is reversed the Sides and the grestest thick
meas of plate used ct the ends. IBe sentences I'M
medistely foreging will prepare the reader for the
information thst every sheet OF ron, ana every
with the greatest accuracy before is shipped
at Liverpool and that, upon arriving en- the back OF
the st. Lawrence, II must not vary half al inch from
the position for which it destined Bus perhaps,
il Will excite wonder at the immense foreshought,
labor ard attention to details which are necessary Tor
such perfect and long be fore-hsnd adj lstment when
state that it s necessary to determine tue position
of 500 different pieces of iron in each of TIE smaller
tubes or Of o. 200 pieces in the whole bridge. This is
like numbering the bricks Of house, and never
putting one in the wrong place. The rvets used in
each tube amount in number TO $1,000, or TO more
than 1900 600 in the entire structure and reck ?ning
the heaos as separate pieces of irop we snail have
more than GOO eco OF Distinct pieces OF metal put
toe ether to form the tubular roadway.
The expansion and contraction OF metal is another
circumstance requiring the attention OF the architect IN
iron. Every is of c0urse aware of this phenome-
non, but perhaps 1t may be novel reflection 70 many
tnst the vast structure poised high in the air absve
the 81. Lawrence, ard apparently 80 firmly fixed, is
yet gong through constant and not inconsiderable
ohsI ges dimensions and and thai instead
of s parts being rigdlY fastened 10 ther places, the
metallic roadway is n fact dssngsged from the stone
piers 10 order 10 allow the tube 10 stretch sef on lts
bed az our readers doubtless accustomed 10 do on
theirs. The principal phenomena OF expansion and
contraction in the tubes two the first s chiefly
in the length, which varies IL summer day some inch
and al S for each tube covering single openiog and
between and winter varies about three aud a.
half inches. The other ie chspge IN form, srlsng
from the fact that the upper oor OF the tube IS ex
posed to the suns rays, while the lower one Is 10 tue
shade. The consequence is greater eng heniug of the
upper than Of the under plates, and certain Texture
OF the tube Such changes, if operating on mass Of
iron about two miles lotg, would be, of course very
difficult 10 manage. The mode OF providing agelnst
its inconvenience, therefore, ia to divide the whole
length Of the roadway into thirteen tubes,one
the large central arcn $50 feet long, and sx on each
side Of H. each formed of two tubes, and each covering
two IT the smaller openings or spsns OF 220 feet. The
two tubes thus made into one thorefcre, rest upon
three pers and resting by the ends 90
two others. The united tube is firmly boted down to
the per which supports it in the middle but the ends
rect upon rollers tha. when they prolonged by
expsrs sion the movemsnt takes place without any
sstsnce. Tie ends of the tubes a. the piers where
they rest on rollers Of course, not in contact.
There is space Of about foot between them for any
play sri, ing from the cause already described.
The weight of iron in the tube, over each of the
smaller openings is 800 turs and the lsrger one
900 tuDs Thus the weight 0f iron n the bridge VIII
be about 81 goo tuns.
The progress made in laying the tubes this year has
been considerable -Four spans are slresdy covered
two on each sidesnd from this time TO the end of the
wo king sessor il is expec ed that two will be
completed each fortnight, making twelve before the
setting in Of the Winter Tie setting 10 OF the
season Of our Canadian year will eff course retsrd
such work but will not entirely stop it, and
tube layirg will be continued In spite Of Frost and
wind and rain and snow. Before leaving the tubes
we ssw stesm-riviiing machine which, though il
cannot accomplish al tne work IN that line owing TO
the difficulty moving il, fsstens great many plates
before they pui up in their pisces. Ii consists OF
ing end OF which humber OF Ces the shapes Of
rivst heads The plates, with TIE rvet PLACED in the
proper no.es beng then presented ~ tnese dies the
steam is allowed TO enter the cylinder, and at
forces tie dies against the rives Ill they pushed
through the holes snd clInched.
Descendrg from the upper works Of the bridge, We
next took boat for the piers. OF these there ara
.ever completed ou each side; two rapidly sp-
preaching completion, ard two are ust OF the point
Of beng begun. 1t lie expected that unless some un-
foressen event takes place, all the piers bas Will
be finished during the present year, or ct least sd
vsrced 20 sr to permit OF the work preceding dur
ing the Winter. AT piers No. 10 H. witnessed
afthe processes employed, from the nnDencenent
Of the day 70 the laying Of tue masonry. or course
the first tling 10 be is TO make padded dam
round the place nteuGsd Jr the foundation Of the