, 1877-04-17

nor overturned bodily, ,by tic hlyh.ss waves thas
are ever likely to run In the vicinity IN which It
ssands.
sounpIras RECENTLY TARan
quite arnnna tho crib. well a. tho e1sminat!ont
6y tho divers, who walked entirely around H. show
se: ses i hs Gs efS ss p S
than It waa before the crib na1 placed u posit!ong
hs ste5 r. hshng ns;s a' % II
doubt due In greater pAft 10 tbs earth dumped
overheard from ihs crib atin9 tho cons:rnction Of
the new lake tunnel But It shows that no wash
NOW, RETURNING TO the DESCRIPTION or TnH
DETAILS OF CONSTRUCTION
aken to 70 brace md liz thc strustars ~ % gve
excellent bond and very great streneth. Tho onscr
te oaE ~ ,,ta M
and inner walls of tIe eri6 Thc outer ansle. q
besa md anglo irons, and BY bolts runnng .hronph
each alternate course Of faeetttnbers back thronEh
Tbs middle walls where tho strain + greatest. Ths
divided by the cross.wAls ard ties described. arc
smaller thnn those which exist IN nnJ crib; work on
ss .sSs sea III sessa mnh l. 4; :%: sn sets
wsile but partially hleI with stone, shoald hare
Continued for % tHreo days T Win no bns sleht
opening Of some Of The Jo,nts Of the snE!es o. ne
m .sns pans
pounding. - the crib did not rest OF THO bottom
when considerably reretntd. tic lowest side occu.
Inc ends and bearing a load equally distributed,
Tho detection Of the aldo # the centre would tend
te2s I'll: IT, oSs Gss%s s sad ' hs asess s s
b sreatly afmin!,hed, 4 not entirely 'emosed.
bulge the sldcs ei tic CRIB remained after il had
n s @ s e e s ps
bullt and re.!iaE partly apon 81. lone !lns, It
10 difficult to reach pfoctsc determination Of
THE LATERAL FltEsaUAn
n the case Of stone; And 1t Is qats certain shst
!he stone ths9wn iato ths compartment. ts o. ths
@ ms.s s; Before = tie mssonry :, sapef:.sustar:.
TSs SowIdsrs were rcuo,ed and liz Foundation of
a protecting wall was sunk surrounding the briek
tower ot ths waagoshanee Light, tioasa wlth'n az
rounded bowlasts upon which T. Essts 80 tn.t ia
sesne sii to exers m ls.ers sis mo.s
cortair, thnt tNcre IL no considerable lateral ptes
aure cxerted BY the ttono n'lIng tho compar!menn
they exert no suck pressure which tho walls Of tho
rttIctute, Tied and oraced - they are: ass
.s, se %ss syy.:s ss' b; 70 s as es o p..s hs
lie VII; woal hold i withoat bnIeing, even i i
bugine 1ad taken place at any time s!uce tho crib
was built whict WAS local In character and not u
9 'enEs Of Tao' ts s0 tn9 ;nT.
wou1i have Geen started. Apti If ilsore. Vas any
working Of tho joints OF thu structure. thts would
~ sseh ipp astatbanes @ wyna g. part'eaiaiy nctisc.
aee as the , snd' q ths ao,sn' wsts s.,
action, II as perfect as It wAa tho day It was put
on n,td t,ut wherever aay jplnt. ~ tho main tim
fcct and close ~ They were in tue beginning. Even
the oaknm rsmai'.t ln ths eeat.e, M and tho pant IN.
tt adl,crcs 10 the tlo,!cra ~ places whefe It was
used In making wattr-ttght ionta.
NO uULGlN0 Oil DISPLACEMENT
II tho walls Of tae bFeakwaser cou'a @ anywhere b.
tuts n'H Il. cna y md
structure IN frttor manifest from tho fact Tint tha
lower eons.cs of thls snpsrst.ue!nro ats entirely
itt oecila.o under these biows IL evident from Tho
ss"n 81 ss .,sk Ct s.s !sxs, %s Z. sst
and Absolutely 50, from tho fact that light Iron
work attachrd 70 the crib and crossing r. almost IN
parin.ent, aud entirely detached trt,m the crib,
never comes In contact with these eytndess, ana
t. !; e. e u H.
henied from shocks proauced BY forces whteh tho
.t.s'ns'h of tho crib il abnnd"at'' sufficient TO
"lheFo soemst thctefose. to 10 no wall grounded
rcason for apprehens!on that the cslb vii 10 Dc;
9[f0tcu piEctt0E&t. n Hak AA6 A{lu1 laE uCcN RAlA
work, upon lie pstnanency Of vhish depends ths
.D as will s}aas,: sasoy htS"R q &, wsa a.5
@ !as .ki!i. sats, and ; e;squsslIat.%es Att viii s.
t. IT, oasiness ssa: Mr j. " sseed n
l!ls design and execution Of lha wurk. whlch con-
-stule. - Vital yast OF tho wstef.supp'y System
VI tho City Of Chicago.
- In the plan and construction OF
TUE MASONRY supKlIsTHUcTuRH,
commencing near tho water surface. oth1r conald.
eFntl0ns than thusc OF ptrlNanrucy scrM to harG
gosesnel. Fram ths hest information havo been
hs I" ge tsom ths rHn. ses 10 5
III. n taickaess. faced on tls oat.iIe with stono
and on .he iualde with brick: rhe three 'owur
sousscs of masonry 10 ~ outer facing sto Of ean"
bat = roughly dressed TINT They could not .
ss, s 5 sts ssg ss1s e p'Sh %sh q s Ss: III i
sSo s asa a bali insls. il width:
s IL assss frS r: s.s sPsa'as IS The
work Of she etlb, from one to ays inehs: n width
IL IL ses ss thS assne ason1y nd
issa think we're dus TO Tho sssain brought 10 bear
up"n them " fsassG q thsss opSnn1&o lS
.ont2 |: iaii IL nissE i seus:e. Ta;s !: s;ss!iy
hy, 70 ihs ;qsk 9s ~
nono can BE- ducovered abore Or below
II. This kind Of cracks arc vsflle
in many u ths abutmonu .of bridges iu r. eIty
composed Of tho s1lno kind Of stone AMI which are
not snbIccse to Ice OF wase action. The heart Of
the wall between The stono and BRICK tacing4 u Of
concrete, and moro than ltktly perfectly suand II
!. wa u EuoA quality whsn la,l: Ths brick, work.
constituting portion Of The sppefstructute, 10 con-
sIlerabiy cracked, anu III probably the eE!steneo
OF such crack. In tbs faco WALL Ut taa supcFatruct-
uru that as given rise 10 any feats that may hare
been honestly entertained y ~ tho parnaneney
and security III ths Glib, by those who h4ve In peF.
sou g!ytu Ii An examination.
TllH INJURY 70 TIE sup8AsTRuCTuRR
may bs prevented ty taxing al shocks Cd oi II. BY
| q GreakwAtcr built sntlfsly around tho crib anu
detached from II; or by msxlng tas supeEstFuet'
urr strung enough 10 Icsist such si!ocks which
e1n b. doas. pehaps, no.. eheaplJ by shsathisF II
pluts extend tat enungh 1aiuw water surface 70
protect ths structure from injury by Ice, and tll,ug
tho space betweta Ihs boiler llata and masoury
With pure cement
Should ons or more blocks Of tho ma.
sonry OF ths supeFstsuctusg be carried away
by tce ur waves, is destruction might proceed with
great Eupldly uhte4s checked by The concrete Ill.
lug, which, i sound aud Set hard, wouh! oder =
stubborn resistance 10 such destructive action.
| *tlt would therefore, aeeul 9dYsAhe IL take