,,bridge ,,disa/]s ,,9 ,,am]ica ,! ,cause & ! ,rem$y ,,by ,,george ,l4 ,,vose ,,au?or ,,( ,,manual ,,= ,,railroad ,,eng9e]s ,,& ,,eng9e]+ ,,/ud5ts1 ,,life ,,& ,,works ,,( ,,george ,w4 ,,:i/l]1 ,,civil ,,eng9e]1 ,,etc4 ,,et]nal ,,vigilance ,,is ,,! ,,price ,,( ,,lib]ty ,,bo/on ,,lee ,,& ,,%ep>d ,,publi%]s #aj ,,milk ,,/reet ,,next ,,old ,,s\? ,,meet+ ,,h\se #ahhg ,,note4 ,! sub/ance ( ! foll[+ pages appe>$ orig9ally 9 ,! ,railroad ,gazette4 ,x 0 aft]w>ds reproduc$ 9 pamphlet =m1 & has s9ce be5 sev]al times deliv]$ z an address to v>i\s bodies1 ! la/ occasion be+ be=e ! ,legislature ( ,massa*usetts1 #ahhg4 ,x is n[ re-publi%$1 ) "s new matt] add$1 9 ! hope t ! public att5tion may be call$ to a subject :i* has s important a be>+ ^u ! public safety4 ,,copyright1 #ahhg1 ,,by ,,lee ,,& ,,%ep>d4 ,all rights res]v$4 ,,bridge ,,disa/]s ,,9 ,,am]ica4 ,ne>ly all ( ! disa/]s :i* occur f ! break+ d[n ( bridges are caus$ by defects :i* w\ld be easily detect$ by an effici5t sy/em ( inspection4 ,n less ?an =ty bridges fall 9 ! ,unit$ ,/ates e ye>4 ,no sy/em ( public inspection or control at pres5t exi/+ has be5 able to detect 9 advance ! defects 9 ^! /ructures1 or to prev5t ! disa/]s4 ,aft] a defective bridge falls1 x is 9 ne>ly e case easy to see :y x did s4 ,x w\ld be j ab\t z easy1 9 mo/ cases1 to tell 9 advance t su* a /ructure w\ld fall if x ev] happ5$ to be heavily load$4 ,hundr$s ( bridges are to-day /&+ 9 ?is c\ntry simply because !y nev] happ5 to h receiv$ ! load :i* is at any "t liable to come ^u !m4 ,a few ye>s ago an iron highway bridge at ,dixon1 ,ill41 fell1 :ile a cr[d 0 ^u x1 & kill$ sixty p]sons4 ,! briefe/ inspection ( t bridge by any compet5t eng9e] w\ld h be5 sure to condemn x4 ,a few ye>s lat] ! ,a%tabula bridge ^u ! ,lake ,%ore ,railroad broke d[n "u an express tra91 & kill$ ov] eighty pass5g]s4 ,! report ( ! committee ( ! ,ohio ,legislature appo9t$ to inve/igate t disa/] conclud$1 fir/1 t ! bridge w5t d[n "u an ord9>y load by reason ( defects 9 its orig9al con/ruction2 &1 secondly1 t ! defects 9 ! orig9al con/ruction ( ! bridge c\ld h be5 discov]$ at any "t aft] its erection by c>eful exam9ation4 ,h>dly _h ! public recov]$ f ! %ock ( ?is t]rible disa/] :5 ! ,t>iffville calamity add$ its li/ ( dead & w\nd$ to ! long roll already *>g$ to ! ignorance & recklessness :i* *>act]ize s mu* ( ! managem5t ( ! public works 9 ?is c\ntry4 ,!re are _m bridges n[ 9 use ^u our railroads 9 no way bett] ?an ^? at ,a%tabula & ,t>iffville1 & :i* await only ! "r comb9ation ( circum/ances to tumble d[n4 ,!re are1 by ! laws ( *ance1 j s _m p]sons :o are go+ to be kill$ on ^? bridges4 ,!re are hundr$s ( highway bridges n[ 9 daily use :i* are 9 no way saf] ?an ! bridge at ,dixon 01 & :i* w\ld c]ta9ly be condemn$ by five m9utes ( compet5t & hone/ inspection4 ,m ?an t1 _m ( !m h already be5 condemn$ z unfit = public use1 b yet are all[$ to rema91 & invite ! disa/] :i* is sure to come4 ,c no?+ be done to prev5t ?is reckless & wick$ wa/e ( human life8 ,c we n h "s sy/em ( public control ( public works :i* %all secure ! public safety8 ,! answ] to ?is "q w be1 ,n until ! public is a good deal m enlight5$ ^u ^! matt]s ?an x is n[4 ,x has be5 v correctly rem>k$1 t1 9 ord] to br+ a disa/] to ! public notice1 x mu/ be emphasiz$ by loss ( life4 ,! ,a%tabula bridge fell1 & kill$ ov] eighty p]sons2 & a /orm ( indignation swept ov] ! c\ntry1 f "o end to ! o!r4 ,no language 0 sev]e en\gh to apply to ! manag]s ( ! ,lake ,%ore ,railroad2 b if t v bridge _h fall5 "u a freight-tra91 & no "o _h be5 injur$1 ! occurr5ce w\ld h be5 dismiss$ ) a p>agraph1 if1 inde$1 x _h receiv$ ev5 t recognition4 ,9 ,febru>y1 #ahgi1 a span "o hundr$ & t5 feet long ( an iron bridge on ! ,*icago & ,alton ,railroad at ,wilm+ton fell z a tra9 ( empty coal-c>s 0 pass+ ov] x1 & ?ree c>s 7 precipitat$ into ! riv]1 a di/ance ( ov] ?irty feet4 ,no "o 0 injur$4 ,n a ^w ( comm5t 0 ev] made 9 reg>d to ?is occurr5ce4 ,suppose1 t1 9 place ( empty coal-c>s1 ! tra9 _h consi/$ ( load$ pass5g]-c>s1 & t "o hundr$ p]sons _h be5 kill$4 ,we "k v well :at ! result w\ld h be54 ,is n ! company j z mu* to blame 9 "o case z ! o!r8 ,on ! night ( ! #h? ( ,novemb]1 #ahgi1 "o span ( ! l>ge bridge ov] ! ,miss\ri at ,/4 ,*>les gave way z a freight-tra9 0 cross+ x1 & sev5te5 load$ /ock-c>s fell a di/ance ( eighty feet into ! riv]4 ,two brakem5 & two drov]s 7 kill$4 ,?is bridge1 says ! only acc\nt t appe>$ 9 ! pap]s1 did n break app>5tly1 = ! :ole span w5t d[n ) ! c>s ^u x4 ,x c\ld h>dly make mu* diff]5ce to ! f\r m5 :o 7 kill$1 :e!r ! bridge broke d[n1 or w5t d[n4 ,n a ^w ( comm5t 0 ev] made 9 ! pap]s outside ( ,miss\ri 9 reg>d to ?is disa/]4 ,suppose1 t1 9 place ( sev5te5 /ock-c>s1 half a doz5 pass5g]-c>s _h fall5 f a height ( eighty feet into ! riv]1 & t1 9 place ( kill+ two brakem5 & two drov]s1 two or ?ree hundr$ pass5g]s _h be5 kill$4 ,is n ! public j z mu* conc]n$ 9 "o case z 9 ! o!r8 ,suppose t a bridge n[ /&+ is exactly z unsafe z ! ,a%tabula bridge 0 ! day be=e x fell1 w\ld x be possible to awak5 public att5tion en\gh to h x exam9$8 ,probably n4 ,ab\t two ye>s ago an attempt 0 made to induce "o ( ! lead+ dailies 9 ?is c\ntry to expose a wret*$ly unsafe bridge 9 ,new ,engl&4 ,! editor decl9$1 on ! gr\nd t ! matt] 0 n ( suffici5t int]e/ = 8 read]s2 b less ?an a mon? aft]w>ds he devot$ ?ree columns ( 8 pap] to a detail$ acc\nt ( a bridge disa/] 9 ,scotl&1 & ask$ :y x 0 t su* ?+s mu/ happ51 & if !re 0 no way ( det]m9+ 9 advance :e!r a bridge 0 safe1 or n8 ,?is editor c]ta9ly w\ld n ma9ta91 t1 9 itself1 x 0 m important to describe a disa/] aft] x _h occurr$ ?an to endeavor to prev5t ! occurr5ce2 b1 z a bus9ess man1 he knew p]fectly well t 8 patrons w\ld read an acc\nt giv+ all ( ! sick5+ detail ( a t]rible cata/rophe1 :ile few1 if any1 w\ld wade ?r\gh a dry discussion ( ! means = protect+ ! public f j su* disa/]s4 ,! public is always v indignant ) ! effect1 b does n c>e to tr\ble itself ) ! cause2 b ! effect nev] w be prev5t$ until ! cause is controll$2 & ! soon] ! public und]/&s t ! cause is 9 its own h&s1 to be controll$1 or n1 z x *ooses1 ! soon] we %all h a rem$y = ! fe>ful disa/]s :i* are altoge!r too common 9 ! ,unit$ ,/ates4 ,9 a c\ntry :]e gov]nm5t controls all matt]s on :i* ! public safety dep5ds1 & :]e no bridge ov] :i* ! public is to pass is all[$ to be built except aft] ! plans h be5 approv$ by compet5t au?ority1 :]e no "w c be execut$ except "u ! rigid inspection ( ! be/ exp]ts1 nor op5$ to ! public until x has be5 (ficially te/$ & accept$1 x makes little or no diff]5ce :e!r ! public is in=m$1 or n1 ^u ^! matt]s2 b 9 a c\ntry l ! ,unit$ ,/ates1 :]e any man may at any "t op5 a %op = ! manufacture ( bridges1 :e!r he kn[s any ?+ ab\t ! bus9ess1 or n1 & is at lib]ty to use *eap & insuffici5t mat]ial1 & :]e public (fic]s are always to be f\nd ready to buy su* bridges1 simply because ! fir/ co/ is l[1 & to place !m 9 ! public ways1 x makes a good deal ( diff]5ce4 ,!re is at pres5t 9 ?is c\ntry absolutely no law1 no control1 no inspection1 :i* c prev5t ! build+ & ! use ( unsafe bridges2 & !re nev] w be until ! p :o make ! laws see ! ne$ ( su* control4 ,!re is no "o ?+ m important 9 ?is matt] ?an t we %\ld be able to fix precisely ! blame 9 case ( disa/] ^u "s p]son to :om ! prop] puni%m5t may be appli$4 ,if e railway director1 or t[n or c\nty (fic]1 knew t he 0 held p]sonally acc\ntable = ! failure ( any bridge 9 8 *>ge1 we %\ld soon h a decid$ improvem5t 9 ^! /ructures4 ,if we c\ld %[ t a c]ta9 bridge 9 a l>ge t[n _h be5 = a long "t old1 rott51 worn out1 & liable at any mom5t to tumble d[n1 & c\ld %[ 9 addition1 t ! public (fic]s hav+ *>ge ( su* a bridge knew ?is to be ! case1 & /ill all[$ ! public to pass ov] x1 we c see at once1 t1 9 case ( disa/]1 ! blame w\ld be cle>ly locat$1 & ! action = damages w\ld be %ort & decisive4 ,once let a t[n h heavy damages to pay1 & let x "k at ! same "t t ! t[n (fic]s are cle>ly acc\ntable = ! loss1 & x is possible t x w\ld be will+ to adopt "s sy/em t %\ld prev5t ! recurr5ce ( su* an outlay4 ,to see :at may be accompli%$ by an effici5t sy/em ( public inspection1 x is necess>y to "k some?+ 9 reg>d to ! /ructures to be inspect$4 ,we h n[ 9 common use 9 ?is c\ntry1 bo? ^u our roads & our railroads1 bridges made entirely ( iron1 bridges ( wood & iron comb9$1 & occasionally1 ?\gh n (t5 n[adays1 a bridge entirely ( wood2 & ^! /ructures are to be se5 ( a great v>iety ( patt]ns1 ( all sizes1 & 9 e /age ( pres]vation4 ,( late s great has be5 ! dem& = bridge-"w1 t ?is bran* ( eng9e]+ has become a trade by itself2 & we f9d imm5se works fitt$ up ) an endless v>iety ( ! mo/ admirably adapt$ ma*9e-tools devot$ exclusively to ! mak+ ( bridges ( wood1 iron1 /eel1 or all comb9$4 ,z 9 all division ( labor1 ! result ( ?is specialization has be5 to improve ! quality ( ! product1 to less5 ! co/1 & to increase ! dem&1 until _m ( our l>ge firms reckon ! l5g? ( bridg+ :i* !y h erect$ by miles in/ead ( feet4 ,z usual1 h[ev]1 9 su* cases1 unpr9cipl$ adv5tur]s are n want+1 :o1 tak+ advantage ( a great dem&1 d n hesitate to fit up *eap %ops1 to buy poor mat]ial1 & to flood ! m>ket ) a class ( bridges made ) a s+le object 9 view1 viz41 to sell1 rely+ ^u ! ignorance--or some?+ worse--( public (ficials = cu/om4 ,n a ye> passes 9 :i* "s ( ^! wret*$ traps d n tumble d[n1 & cause a great] or less loss ( life1 & at ! same "t1 ) un9=m$ p1 ?r[ discr$it on ! :ole mod]n sy/em ( bridge-build+4 ,?is evil affects p>ticul>ly highway bridges4 ,! ord9>y c\nty commission] or selectman consid]s himself amply compet5t to contract = a bridge ( wood or iron1 ?\gh he may nev] h giv5 a s+le day ( ?\ght to ! matt] be=e 8 appo9tm5t to (fice4 ,! result is1 t we see all ov] ! c\ntry a great numb] ( highway bridges :i* h be5 sold by di%one/ build]s to ignorant (ficials1 & :i* are on ! eve ( fall+1 & await only an extra l>ge cr[d ( p1 a company ( soldi]s1 a procession1 or some?+ ( ! sort1 to break d[n4 ,n _m ye>s ago1 a new highway bridge ( iron 0 to be made ov] "o ( ! pr9cipal riv]s 9 ,new ,engl&4 ,! c\nty commission]s desir$ a well-kn[n eng9e]1 especially not$ z a bridge-build]1 to sup]9t5d ! "w1 9 ord] to see t x 0 prop]ly execut$4 ,! eng9e]1 aft] inspection ( ! plans1 told ! commission]s pla9ly t ! design 0 defective1 & w\ld n make a safe bridge2 & t1 unless x 0 mat]ially *ang$1 he w\ld h no?+ to d ) x4 ,! bridge1 h[ev]1 0 a *eap "o1 &1 z su*1 comm5d$ itself to ! commission]s1 :o proce$$ to h x erect$ accord+ to ! orig9al plan2 & ^! same commission]s n[ po9t to t bridge1 :i* has n yet fall51 b :i* is liable to d s at any "t1 z a complete v9dication ( _! judgm5t1 s call$1 z oppos$ to t ( ! eng9e] :o _h sp5t 8 life 9 build+ bridges4 ,an impression exi/s 9 ! m9ds ( _m p]sons1 t x is purely a matt] ( op9ion :e!r a bridge is safe1 or n4 ,9 v _m cases1 h[ev]1--p]haps 9 mo/1--x is n at all a matt] ( op9ion1 b a matt] ( fact & ( ari?metic4 ,! :ole "q always comes to ?is3 ,is ! mat]ial 9 ?is bridge ( good quality8 ,is !re en\gh ( x8 ,is x correctly dispos$1 & prop]ly put toge!r8 ,) giv5 dim5sions1 & kn[+ ! load to be c>ri$1 x is a matt] ( ! v simple/ computation to fix ! size ( ea* memb]4 ,we "k :at "o squ>e in* ( iron w hold1 & we "k1 also1 ! total numb] ( p\nds to be su/a9$2 & x is no matt] ( op9ion1 b "o ( simple division1 h[ _m times "o w g into ! o!r4 ,b x may be ask$1 ,c ! precise load :i* is com+ ^u any /ructure be exactly fix$8 are n ! circum/ances "u :i* bridges are load$ v diff]5t8 ,bridges 9 diff]5t localities are c]ta9ly subject$ to v diff]5t loads1 & "u v diff]5t conditions2 b ! prop] loads to be provid$ = h be5 fix$ by ! be/ au?ority = all cases )9 n>r[ en\gh limits = all practical purposes4 ,few p]sons are aw>e ( ! weight ( a closely pack$ cr[d ( p4 ,mr4 ,/oney ( ,dubl91 "o ( ! be/ au?orities1 pack$ #cj p]sons ^u an area ( a little less ?an #cj squ>e feet2 & at ano!r "t he plac$ #eh p]sons ^u an area ( #eg squ>e feet1 ! result+ load 9 ! two cases be+ v ne>ly #aej p\nds to ! squ>e foot4 ,su* cramm+1 says ,mr4 ,/oney1 c\ld sc>cely occur 9 practice1 except 9 portions ( a /rongly excit$ cr[d2 b ,i h no d\bt t x does occasionally s occur4 ,9 my own practice1 he cont9ues1 ,i adopt #ajj p\nds p] squ>e foot z ! /&>d work+-load di/ribut$ uni=mly ov] ! :ole surface ( a public bridge1 & #adj p\nds p] squ>e foot = c]ta9 portions ( ! /ructure1 su*1 = example1 z ! foot-pa?s ( a bridge cross+ a navigable riv] 9 a city1 :i* are liable to be sev]ely tri$ by an excit$ cr[d dur+ a boat-race1 or "s simil> occasion4 ,tr$gold & ,rank9e e/imate ! weight ( a d5se cr[d at #abj p\nds p] squ>e foot4 ,mr4 ,brunel us$ #ajj p\nds 9 8 calculations = ! ,hung]=d ,susp5sion ,bridge4 ,mr4 ,drewry1 an old b excell5t au?ority1 obs]ves t any body ( m5 m>*+ 9 /ep at f #c to #c-a_/b miles an h\r w /ra9 a bridge at lea/ z mu* z d\ble ! same weight at re/2 & he adds1 ,9 prud5ce1 n m ?an "o-six? ! numb] ( infantry t w\ld fill a bridge %\ld be p]mitt$ to m>* ov] x 9 /ep4 ,mr4 ,roebl+ says1 9 speak+ ( ! ,niag>a ,falls ,susp5sion ,bridge1 ,9 my op9ion1 a heavy tra91 runn+ at a spe$ ( #bj miles an h\r1 does less injury to ! /ructure ?an is caus$ by #bj heavy cattle "u full trot4 ,public processions m>*+ to ! s\nd ( music1 or bodies ( soldi]s keep+ regul> /ep1 w produce a /ill m injuri\s effect4 ,evid5tly a diff]5ce %\ld be made 9 det]m9+ ! load = ,london ,bridge & ! load = a highway bridge ^u a ,new-,engl& c\ntry road 9 a ?9ly settl$ di/rict4 ,a bridge t is /rong en\gh is j z good & j z safe z "o t is t5 times /rong]1 & ev5 bett]2 = 9 a l>ge bridge1 if we make x too /rong1 we make x at ! same "t too heavy4 ,! weight ( ! /ructure itself has to be su/a9$1 & ?is "p ( ! load is a p]petual drag on ! mat]ial4 ,9 #ahge ! ,am]ican ,society ( ,civil ,eng9e]s1 9 view ( ! repeat$ bridge disa/]s 9 ?is c\ntry1 appo9t$ a committee to report ^u ,! ,means ( ,av]t+ ,bridge ,accid5ts4 ,we might expect1 :5 a society compos$ ( "s hundr$s ( our be/ eng9e]s selects an exp]t committee ( half a doz5 m51 t ! be/ au?ority w\ld be pretty well repres5t$2 & su* 0 em95tly ! case4 ,x w\ld be impossible to h comb9$ a great] am\nt ( ackn[l$g$ tal5t1 bo? !oretical & practical1 ) a wid] & m valuable exp]i5ce ?an ?is committee possess$4 ,! fir/ po9t tak5 up 9 ! report is ! det]m9ation ( ! loads = :i* bo? railroad & highway bridges %\ld be proportion$4 ,9 reg>d to highway bridges1 a majority ( ! committee report$ t = su* /ructures ! /&>d loads %\ld n be less ?an z %[n 9 ! foll[+ table3-- ---------------------------------------- --------- ,,p\nds ,,p] ,,squ>e ,,foot4 ,,span4 ------------------------------ ,,class ,a4 ,,class ,b4 ,,class ,c4 ---------------------------------------- --------- #fj feet & less #ajj #ajj #gj #fj to #ajj feet #ij #ge #fj #ajj to #bjj feet #ge #fj #ej #bjj to #djj feet #fj #ej #dj ---------------------------------------- --------- ,class ,a includes city & suburban bridges1 & ^? ov] l>ge riv]s1 :]e great conc5tration ( weight is possible4 ,class ,b d5otes highway bridges 9 manufactur+ di/ricts hav+ well-balla/$ roads4 ,class ,c ref]s to ord9>y c\ntry-road bridges1 :]e travel is less frequ5t & light]4 ,a m9ority ( ! committee modifi$ ! table above by mak+ ! loads a little l>g]4 ,! :ole committee agre$ 9 mak+ ! load p] squ>e foot less z ! span is great]1 :i* is1 ( c\rse1 correct4 ,x w\ld seem em95tly prop] to make a diff]5ce betwe5 a bridge :i* c>ries ! cont9u\s & heavy traffic ( a l>ge city1 & "o :i* is subject$ only to ! comp>atively light & infrequ5t traffic ( a c\ntry road4 ,at ! same "t x %\ld n be =gott51 t1 9 a l>ge "p ( ! ,unit$ ,/ates1 a bridge may be load$ by t51 fifte51 or ev5 tw5ty p\nds p] squ>e foot by sn[ & ice alone1 & t ! v bridges :i* f _! location we %\ld be apt to make ! lighte/1 are ^? :i* w\ld be mo/ likely to be neglect$1 & n reliev$ f a heavy accumulation ( sn[4 ,9 view ( ! above1 & rememb]+ t a mov+ load produces a mu* great] /ra9 ^u a bridge ?an "o :i* is at re/1 we may be sure1 t1 z ! committee above ref]r$ to recomm5d1 ! loads %\ld n be less ?an ^? giv5 9 ! table4 ,we c easily see t 9 special cases !y %\ld be m4 ,!re is ano!r po9t 9 reg>d to load+ a highway bridge1 :i* is to be consid]$4 ,x (t5 happ5s t a v heavy load is c>ri$ ov] su* bridges ^u a s+le truck1 ?us ?r[+ a heavy & conc5trat$ load ^u ea* po9t z x passes4 ,mr4 ,/oney /ates t a wagon ) a crank-%aft ( ! ,briti% %ip ,h]cules1 weigh+ ab\t =ty-five tons1 0 refus$ a passage ov] ,we/m9/] iron bridge1 = fe> ( damage to ! /ructure1 & _h to be c>ri$ ov] ,wat]loo bridge1 :i* is ( /one2 & he says t 9 _m cases l>ge boil]s1 heavy =g+s1 or ca/+s rea* z high z twelve tons ^u a s+le :eel4 ,! report ( ! ,am]ican ,society ( ,civil ,eng9e]s1 above ref]r$ to1 advises t ! floor sy/em be /rong en\gh to c>ry ! foll[+ loads ^u f\r :eels3 ,class ,a1 #bd tons2 ,class ,b1 #af tons2 ,class ,c1 #h tons2 ?\gh x is /at$ t ^! d n include ! extraord9>y loads sometimes tak5 ov] highways4 ,?is provision = local loads1 says ,mr4 ,boll]1 "o ( ! committee1 may seem extreme2 b ! j> & jolt ( heavy1 spr+-less loads come directly on all p>ts ( ! floor+ at successive int]vals1 & admoni% u t any errors %\ld be on ! safe side4 ,to pass n[ to railroad bridges1 we f9d "h a v heavy load com+ ^u ! /ructure 9 a sudd51 & (t5 v viol5t1 mann]4 ,exp]im5t & obs]vation bo? indicate t a rapidly mov+ load produces an effect equal to d\ble ! same load at re/4 ,?is effect is se5 mu* m ^u %ort bridges1 :]e ! mov+ load is l>ge 9 proportion to ! weight ( ! bridge1 ?an ^u long spans1 :]e ! weight ( ! bridge itself is consid]able4 ,! actual load ^u a %ort bridge is also m p] foot ?an ^u a long "o1 because ! locomotive1 :i* is mu* heavi] ?an an equal l5g? ( c>s1 may cov] ! :ole ( a %ort span1 b only a "p ( a long] "o4 ,! l>ge/ eng9es 9 use ^u our railroads weigh f #ge1jjj to #hj1jjj p\nds on a :eel-base ( n ov] twelve feet 9 l5g?1 or #b1hjj p\nds p] foot = ! :ole l5g? ( ! eng9e1 & f #bj1jjj to #bd1jjj p\nds on a s+le pair ( :eels4 ,! heavie/ coal-tra9s w weigh ne>ly a ton to ! foot1 ord9>y freight-tra9s f #a1fjj to #a1hjj p\nds1 & pass5g]-tra9s f #a1jjj to #a1bjj p\nds p] foot4 ,any bridge is liable to be trav]s$ by two heavy freight-eng9es foll[$ by a load ( ?ree-qu>t]s ( a ton to ! foot2 s t if we proportion a bridge to c>ry #c1jjj p\nds p] foot = ! total eng9e l5g?1 & "o ton p] foot = ! re/ ( ! bridge1 be>+ 9 m9d t any "o po9t may be call$ ^u to su/a9 #bd1jjj p\nds1 & reg>d+ ! increase ( /ra9 ^u %ort spans due to high spe$s1 we h ! foll[+ loads = diff]5t spans exclusive ( ! weight ( ! bridge3-- -------------------------- ,,span4 ,,lbs4 ,,p] ,,foot4 -------------------------- #ab #g1jjj -------------------------- #ae #f1jjj -------------------------- #bj #d1hjj -------------------------- #be #d1jjj -------------------------- #cj #c1fjj -------------------------- #dj #c1bjj -------------------------- #ej #c1jjj -------------------------- #ajj #b1hjj -------------------------- #bjj #b1fjj -------------------------- #cjj #b1ejj -------------------------- #djj #b1dej -------------------------- #ejj #b1djj -------------------------- ,! above does n v>y ess5tially f ! ,engli% practice1 & is sub/antially ! same z giv5 by ! committee ( ! ,am]ican ,society ( ,civil ,eng9e]s4 ,! load :i* any bridge w be requir$ to c>ry be+ det]m9$1 & ! g5]al plan & dim5sions fix$1 ! sev]al /ra9s ^u ! diff]5t memb]s foll[ by a simple process ( ari?metic1 leav+ to be det]m9$ ! actual dim5sions ( ! v>i\s p>ts1 a matt] :i* dep5ds ^u ! p[] ( diff]5t k9ds ( mat]ial to resi/ diff]5t /ra9s4 ,?is br+s u to ! exce$+ly important subject ( ! nature & /r5g? ( mat]ials4 ,x has be5 said t we "k :at "o squ>e in* ( iron w hold4 ,l ! "q ( loads above exam9$1 ?is is a matt] :i* has be5 settl$1 at any rate )9 v n>r[ limits1 by ! exp]i5ce ( _m ye>s ( bo? ,european & ,am]ican eng9e]s4 ,a b> ( ! be/ wr\ght-iron an in* squ>e w n break "u a t5sile /ra9 ( less ?an sixty ?\s& p\nds4 ,only a small "p ( ?is1 h[ev]1 is to be us$ 9 practice4 ,a b> or beam may be load$ ) a great] weight appli$ z a p]man5t or dead-load ?an w\ld be safe z a roll+ or mov+ weight4 ,a load may be br\ght ^u any mat]ial 9 an easy & gradual mann]1 s z n to damage x2 :ile ! same load c\ld n be sudd5ly & viol5tly appli$ )\t injury4 ,! m>g9 = safety %\ld be great] ) a mat]ial liable to conta9 hidd5 defects1 ?an ) "o :i* is n s2 & x %\ld be great] ) any memb] ( a bridge :i* is subject$ to sev]al diff]5t k9ds ( /ra91 ?an = "o :i* has to resi/ only a s+le =m ( /ra94 ,respect1 also1 %\ld be _h to ! frequ5cy ) :i* any "p is subject$ to /ra9 f a mov+ load1 z ?is w influ5ce its p[] ( endurance4 ,! rule 9 /ructures hav+ s important an (fice to p]=m z railroad or highway bridges1 %\ld be1 9 all cases1 absolute safety "u all conditions4 ,! ,briti% ,bo>d ( ,trade fixes ! greate/ /ra9 t %all come ^u ! mat]ial 9 a wr\ght-iron bridge1 f ! comb9$ weight ( ! bridge & load1 at #e tons p] squ>e in* ( ! net section ( ! metal4 ,! ,fr5* practice all[s #c-h_/aj tons p] squ>e in* ( ! cross section ( ! metal1 :i*1 consid]+ ! am\nt tak5 out by rivet-holes1 is sub/antially ! same z ! ,engli% all[ance4 ,! report ( ! ,am]ican ,society ( ,civil ,eng9e]s1 above ref]r$ to1 recomm5ds #aj1jjj p\nds p] in* z ! maximum = wr\ght-iron 9 t5sion 9 railroad bridges4 ,= highway bridges a unit /ra9 ( #ae1jjj p\nds p] squ>e in* is (t5 all[$4 ,a v common clause 9 a specification is t ! factor ( safety %all be f\r1 five1 or six1 z ! case may be1 mean+ by ?is t ! actual load %all n exce$ "o-f\r?1 "o-fif?1 or "o-six? "p ( ! break+-load4 ,x is a little un=tunate t ?is t]m1 factor ( safety1 has f\nd its way into use j z x has2 = x by no means indicates :at is int5d$1 or :at x is suppos$ to4 ,! true m>g9 = safety is n ! diff]5ce betwe5 ! work+-/ra9 & ! break+-/ra91 b betwe5 ! work+-/ra9 & t /ra9 :i* w 9 any way unfit ! mat]ial = use4 ,n[1 any mat]ial is unfitt$ = use :5 x is s f> di/ort$ by ov]/ra9+ t x _c recov]1 or1 te*nically speak+1 :5 its ela/ic limit has be5 exce$$4 ,! ela/ic limit ( ! be/ grades ( iron is j ab\t half ! break+-weight1 or f #be1jjj to #cj1jjj p\nds p] in*4 ,a poor iron w (t5 %[ a v fair break+-/r5g?1 b1 at ! same "t1 w h a v l[ ela/ic limit1 & be entirely unfit = use 9 a bridge4 ,a piece ( iron ( v inf]ior quality w (t5 su/a9 a great] load be=e break+ ?an a piece ( ! be/ & t\ghe/ mat]ial1 = ! reason t a t\gh b ductile iron w /ret* be=e giv+ way1 ?us r$uc+ ! area ( section1 :ile a h>d b poor iron w keep ne>ly its full size until x breaks4 ,a t\gh & ductile iron %\ld b5d d\ble1 :5 cold1 )\t %[+ any signs ( fracture1 & %\ld /ret* fifte5 p] c5t ( its l5g? be=e break+2 b mu* ( ! iron us$ 9 bridges1 al?\gh x may hold #dj1jjj or #ej1jjj p\nds p] in* be=e fail+1 w n b5d ov] #ij degrees )\t crack+1 & has an ela/ic limit z l[ z #ah1jjj p\nds4 ,x is ?us full z important to specify t an iron %\ld h a high ela/ic limit z t x %\ld h a high break+-weight4 ,a specification :i* all[$ no mat]ial to be /ra9$ by m ?an #aj1jjj p\nds p] in*1 & no iron to be us$ ) a less ela/ic limit ?an #be1jjj p\nds1 w\ld1 at ! same "t1 agree ) ! /&>d requirem5t1 bo? 9 ,engl& & 9 ! ,unit$ ,/ates1 & w\ld also secure a good quality ( iron4 ,two docum5ts publi%$ "s "t s9ce illu/rate ! prec$+ rem>ks4 ,! fir/ is ! acc\nt ( ! te/s ( ! iron tak5 f ! ,t>iffville bridge aft] its failure1 & ! second is ! specification = bridges on ! ,c9c9nati ,s\!rn ,railroad4 ,! ,t>iffville bridge1 ?\gh nom9ally a wood5 "o1 l mo/ /ructures ( ! k9d reli$ entirely ^u iron rods to keep ! wood-"w toge!r4 ,al?\gh ! rods 7 too small1 & s]i\sly defective 9 manufacture1 ! bridge ought n to h fall5 f t cause4 ,! ultimate /r5g? ( ! iron 0 n :at x %\ld h be51 b yet x 0 n l[ en\gh to expla9 ! disa/]2 b :5 we look at ! quality ( ! iron1 we h ! cause ( ! fall4 ,! rods tak5 f ! bridge %[ an ultimate t5sile /r5g? ( #dg1efj p\nds p] in*1 b an ela/ic limit ( only #ai1jjj p\nds2 :ile ! /ra9 :i* 0 at any "t liable to come on !m 0 #bb1jjj p\nds p] in*1 or #c1jjj p\nds m ?an ! ela/ic limit4 ,! fracture ( ! te/$ rods1 :i*1 x is /at$1 broke ) a s+le bl[ ( ! hamm] v mu* 9 ! mann] ( ca/-iron1 %[$ a v inf]ior quality ( metal4 ,! rods broke 9 ! bridge exactly :]e we %\ld look = ! failure2 viz41 9 ! screw at ! end4 ,no ord9>y inspection w\ld h detect$ ?is weakness4 ,no inspection did detect x1 b a prop] specification fai?fully c>ri$ out w\ld h prev5t$ ! disa/]4 ,look n[ at an extract f ! specification = bridges ^u ! ,c9c9nati ,s\!rn ,railway3-- ,all p>ts ( ! bridges & tre/leworks mu/ be proportion$ to su/a9 ! passage ( ! foll[+ roll+-load at a spe$ ( n less ?an #cj miles an h\r3 viz41 two locomotives c\pl$1 ea* weigh+ #cf tons on ! driv]s 9 a space ( #ab feet1 ! total weight ( ea* eng9e & t5d] load$ be+ #ff tons 9 a space ( #ej feet1 & foll[$ by load$ c>s weigh+ #bj tons ea* 9 a space ( #bb feet4 ,an addition ( #be p] c5t w be made to ! /ra9s produc$ by ! roll+-load consid]$ z /atic 9 all p>ts :i* are liable to be ?r[n sudd5ly "u /ra9 by ! passage ( a rapidly mov+ load4 ,a simil> addition ( #ej p] c5t w be made to ! /ra9 on susp5sion l9ks & rivet$ connections ( /r+]s ) floor-beams1 & floor-beams ) trusses4 ,! iron-"w %all be s proportion$ t ! weight ( ! /ructure1 toge!r ) ! above specifi$ roll+-load1 %all 9 no "p cause a t5sile /ra9 ( m ?an #aj1jjj p\nds p] squ>e in* ( sectional area4 ,iron us$ "u t5sile /ra9 %all be t\gh1 ductile1 ( uni=m quality1 & capable ( su/a9+ n less ?an #ej1jjj p\nds p] squ>e in* ( sectional area )\t fracture1 & #be1jjj p\nds p] squ>e in* )\t tak+ a p]man5t set4 ,! r$uction ( area at ! break+-po9t %all av]age #be p] c5t1 & ! elongation #ae p] c5t4 ,:5 cold1 ! iron mu/ b5d1 )\t sign ( fracture1 f #ij to #ahj degrees4 ,a specification l ?is1 prop]ly c>ri$ out1 w\ld put an absolute /op to ! build+ ( su* /ructures z ! ,t>iffville ,bridge1 & w\ld prev5t a v l>ge "p ( ! cata/rophes :i* s (t5 %ock ! community1 & %ake ! public fai? 9 iron bridges4 ,ref]5ce has be5 made above to ! prop] loads to be plac$ ^u wr\ght-iron :5 "u a t5sile /ra94 ,simil> loads h be5 det]m9$ = o!r mat]ials1 & = o!r k9ds ( /ra94 ,! prec$+ rem>ks 9 reg>d to ! loads = :i* bridges %\ld be design$1 & ! safe weight to be put ^u ! mat]ial1 are giv5 to %[ h[ f> ! safety ( a bridge is a matt] ( fact1 & h[ f> a matt] ( op9ion4 ,x w be se5 t ! limits )9 :i* we are at lib]ty to v>y1 are q n>r[1 s t bridge-build+ may correctly be call$ a sci5ce2 & !re is no excuse = ! p]son :o guesses1 ei!r at ! load :i* a bridge %\ld be design$ to be>1 or at ! size ( ! diff]5t memb]s ( ! /ructure4 ,/ill less c we excuse ! man :o n only guesses1 b :o1 9 ord] to build *eaply1 p]si/5tly guesses on ! wrong side4 ,x w1 ( c\rse1 be und]/ood1 :5 x is said t bridge-build+ may be call$ a sci5ce1 t x c only be s :5 9 ! h&s ( an eng9e] ^: judgm5t has be5 matur$ by wide exp]i5ce1 & :o und]/&s t no me*anical philosophy c be appli$ to practice :i* is n subject to ! cont+5cies ( workman%ip4 ,!re are _m bridges :i* w /& ! te/ ( figures v well1 & :i* are nev]!less v poor /ructures4 ,! g5]al plan ( a bridge may be good1 ! computations all "r1 & yet x may break d[n "u ! fir/ tra9 t passes ov] x4 ,!re are _m practical consid]ations t _c be1 at any rate h n yet be51 r$uc$ to figures4 ,x is n en\gh t ! /ra9s ^u ea* memb] ( a bridge %\ld be correctly e/imat$1 & fall )9 ! safe limits3 ! diff]5t memb]s ( ! bridge mu/ be s connect$1 & ! me*anical details su*1 z to insure1 "u all conditions1 ! assum$ action ( ! sev]al p>ts4 ,9 f9e1 :ile we c say t a bridge t does n /& ! te/ ( ari?metic is a bad bridge1 we _c always say t a /ructure :i* does /& su* a te/ is a good "o4 ,we (t5 he> x argu$ t a bridge mu/ be safe1 s9ce x has be5 submitt$ to a heavy load1 & did n break d[n4 ,su* a te/ means absolutely no?+4 ,x does n ev5 %[ t ! bridge w be> ! same load aga91 mu* less does x %[ t x has ! prop] m>g9 = safety4 ,x simply %[s t x did n break d[n at t "t4 ,e rott51 worn-out1 & defective bridge t ev] fell has be5 submitt$ to exactly t te/4 ,m ?an ?is1 x has repeat$ly happ5$ t a heavy tra9 has pass$ ov] a bridge 9 app>5t safety1 :ile a mu* light] "o pass+ directly aft]w>ds has gone ?r\gh4 ,9 almo/ all su* cases1 ! /ructure has be5 weak & defective2 & f9ally "s heavy load passes ov]1 & cripples ! bridge1 s t ! next load produces a disa/]4 ,= ! te/ ( a bridge to be 9 any way satisfactory1 we mu/ "k j :at effect su* te/ has _h ^u ! /ructure4 ,we d n f9d ?is out by simply /&+ ne>1 & not+ t ! bridge did n break d[n4 ,we mu/ satisfy ourselves beyond all "q t no "p has be5 ov]/ra9$4 ,a %ort "t ago ! build]s ( a wret*$ly *eap & unsafe highway bridge1 9 ord] to quiet a fe> :i* _h aris5 t ! /ructure 0 n altoge!r s\nd1 te/$ a span #abb feet long ) a load ( #eh1jjj p\nds2 & inasmu* z ! bridge did n break d[n "u ?is load1 :i* 0 less ?an a qu>t] "p ( :at x 0 w>rant$ to c>ry safely1 ! c\nty commission]s consid]$ ! result em95tly satisfactory1 & rem>k$ t ! te/ 0 made m]ely to satisfy ! public t ! bridge 0 abundantly safe = all practical uses4 ,! public w\ld1 no d\bt1 h be5 satisfi$ t ! ,a%tabula bridge 0 abundantly safe = all practical uses _h x /ood on t bridge 9 ! morn+ & se5 a heavy freight-tra9 g ov] x1 & yet t v bridge broke d[n directly aft]w>ds "u a pass5g]-tra94 ,n[1 accord+ to ! common notion1 t 0 a good bridge 9 ! morn+1 & a v bad bridge1 or r1 no bridge at all1 9 ! ev5+4 ,! "q = ! public is1 ,:5 did x cease to be a good bridge1 & beg9 to be a bad "o8 ,a te/ l ! "o ref]r$ to above c d no m ?an illu/rate ! ignorance or lack ( hone/y ( ^? :o make x1 or ^? :o are satisfi$ ) x4 ,su* a te/ might come )9 a doz5 p\nds ( break+ ! bridge d[n1 & no "o be ! wis]4 ,! entire absurdity ( su* te/+ has rec5tly be5 illu/rat$ 9 ! mo/ decid$ mann]4 ,! v same company t built ! bridge above ref]r$ to1 made also ano!r "o on exactly ! same plan1 & ( almo/ precisely ! same size1 & te/$ x :5 done by plac+ almo/ exactly ! same load ^u x4 ,! bridge did n break d[n2 & ! c\nty commission]s1 = :om ! "w 0 done1 7 satisfi$ t x 0 abundantly safe = all practical uses1 accept$ x1 paid = x2 & 9 less ?an t5 ye>s x broke d[n "u a s+le team & a little sn[1 weigh+ 9 all n ov] "o-t5? "p ( ! load ! bridge 0 w>rant$ to c>ry1 & n ov] "o-half ! load ) :i* x _h be5 previ\sly te/$4 ,if ?is bridge _h be5 te/$ by five m9utes ( hone/ ari?metic1 x w\ld h be5 promptly condemn$ ! v day x 0 f9i%$4 ,9 view ( ! prec$+1 :at %all we say ( a bridge company t delib]ately builds a bridge 9 ! middle ( a l>ge t[n1 :]e x w be subject$ to heavy team+1 &1 ow+ to its peculi> location1 to heavy cr[ds1 & w>rants to ! t[n t x %all safely hold a ton p] runn+-foot1 :5 ! v simple/ computation %[s beyond *ance ( dispute t su* a load w /ra9 ! iron to #dj1jjj p\nds p] squ>e in*8 ,we are to say1 ei!r t su* a company is s ignorant t x does n "k ! diff]5ce betwe5 a good bridge & a bad "o1 or else s wick$ z to kn[+ly subject ! public to a wret*$ly unsafe bridge4 ,! case ref]r$ to is n an imag9>y "o1 b exi/$ rec5tly 9 ! ma9 /reet ( a l>ge ,new-,engl& t[n4 ,! jo9ts 9 t bridge1 :i* c\ld safely hold b #bj1jjj p\nds1 7 requir$ to hold #fj1jjj p\nds "u ! load :i* ! build]s _h w>rant$ ! bridge to c>ry safely4 ,! case 0 s bad1 t1 aft] a l5g?y controv]sy1 ! t[n (fic]s _h a ?or\gh exp]t exam9ation ( ! bridge1 :i* promptly condemn$ x z 9 imm95t dang] ( fall+1 & z hav+ a factor ( safety ( only #a-ae_/ajj1 :i* is practically no factor at all4 ,not)/&+ all ?is1 & 9 ! face ( ! report1 ! presid5t ( ! bridge company came out ) a lett] 9 ! pap]s1 9 :i* he pron\nc$ ! bridge p]fectly safe4 ,?us we actually h ! presid5t ( a bridge company 9 ?is c\ntry /at+ op5ly t a factor ( safety ( #a-ae_/ajj makes a bridge p]fectly safe1 or1 9 o!r words1 t a bridge c safely be> ! load t w break x d[n1 = he v wisely made n ! slighte/ attempt to disprove any ( ! conclusions ( ! commission2 & ?is company has built hundr$s ( highway bridges all ov] ! ,unit$ ,/ates1 & is build+ !m to-day :]ev] x c f9d t[n or c\nty (fic]s ignorant en\gh to buy !m4 ,x might be suppos$1 t1 "u ! above condemnation1 ! au?orities controll+ ! bridge w\ld h tak5 "s /eps to prev5t ! com+ disa/]4 ,!y did1 h[ev]1 no?+ ( ! k9d1 b all[$ ! public to travel ov] x = m ?an a ye>1 at ! mo/ fe>ful risk1 until public indignation became s /rong t a special t[n-meet+ 0 call$1 & a committee appo9t$ to remove ! old bridge1 & to build a new "o4 ,"o ( ! wor/ cases ( utt]ly di%one/ bridge-build+ t we h _h ( late ye>s 9 ,massa*usetts1 0 t ( ! iron highway bridge across ! ,m]rimac ,riv] at ,grovel&1 a few miles bel[ ,hav]hill1 "o span ( :i* broke d[n 9 ,janu>y1 #ahha4 ,?is bridge 0 built 9 #ahga-ahgb1 & consi/$ ( #f spans1 ea* ab\t #abe feet long4 ,! :ole co/ ( ! /ructure 0 #hj1jjj1 & ! contract price = ! iron-"w 0 #bh1jjj4 ,! company :i* made t bridge1 agre$ 9 _! contract to give ! c\nty a /ructure t %\ld c>ry safely #c1jjj p\nds p] runn+-foot besides its own weight2 b !y built a bridge1 :i*1 if !y knew en\gh to compute its /r5g? at all1 !y knew p]fectly well c\ld n safely c>ry ov] "o-qu>t] "p ( t load4 ,9 fact1 ! weight ( ! bridge alone is m ?an x ev] ought to h borne4 ,! company w>rant$ ea* span ( t bridge to c>ry safely a net or mov+ load ( #afe tons1 & x broke d[n "u a s+le team & a small am\nt ( sn[4 ,! company w>rant$ t bridge to c>ry safely a load :i* w\ld /ra9 ! iron to #ej1jjj p\nds p] in*1 :5 x knew p]fectly well t #ae1jjj p\nds p] in* 0 ! mo/ t c\ld safely be borne4 ,!re are sev]al conc]ns 9 ! ,unit$ ,/ates :i* make a specialty ( highway bridges1 & :i*1 tak+ advantage ( ! ignorance ( public (ficials1 are flood+ ! c\ntry ) bridges no bett] ?an t at ,grovel&4 ,on an av]age1 at lea/ tw5ty ( ^! mis]able traps tumble d[n e ye>1 & no?+ is done to br+ ! guilty p>ties to puni%m5t4 ,di%one/ build]s *eat ignorant (ficials1 & ! public suff]s ! damage & pays ! bills4 ,is human life wor? en\gh to pay = hav+ ^! /ructures inspect$1 &1 if f\nd unsafe1 /r5g!n$ or remov$8 ,c we d any ?+ to prev5t t[ns & c\nties f be+ impos$ ^u by di%one/ build]s8 ,we c]ta9ly c1 if ^? :o control ^! matt]s c>e en\gh ab\t x to d x4 ,!re are two ways ( buy+ a bridge1--a good way & a bad "o2 & ^! two ways are s pla9 t no "o c misund]/&4 ,to buy a bad bridge1 j z soon z y\r t[n or c\nty votes money = a new bridge1 c]ta9 ag5ts--& !y are z num]\s z ! ag5ts = sew+-ma*9es or lightn+-rods--w call on1 or write to1 ! t[n or c\nty (fic]s1 & w (f] to build any ?+ "u heav5s y want ( any size1 %ape1 or mat]ial1 & = almo/ any price4 ,!y w produce te/imonials f all ! t[n & c\nty (fic]s 9 ! c\ntry = ! excell5ce ( _! bridges1 & w\ld n hesitate to give ref]5ce1 ev51 = _! moral "*1 if y %\ld ask x4 ,if !y f9d t y don't "k any ?+ ab\t bridges1 !y w1 to save y ! tr\ble1 furni% a pr9t$ specification2 :i* docum5t w commit y to pay ! money1 b w n commit ! bridge company to any ?+ at all4 ,:5 ! bridge is put up1 y nev] w "k :e!r ! iron is good or bad1 nor :e!r ! dim5sions & proportions are su* z to be safe or n4 ,y w "k t y h paid y\r money away1 b y nev] w "k :at y h got = x until "s day :5 y\r bridge gets a cr[d ^u x1 & breaks d[n1 & y h ! damage to pay4 ,?is mode ( buy+ a bridge is v common4 ,to buy a good bridge1 fir/ det]m9e precisely :at y want2 & if y don't "k any ?+ 9 reg>d to bridge-build+ y\rself1 employ an eng9e] :o does1 to make a specification /at+ exactly :at y want1 & :at y mean to h4 ,!n adv]tise = bridge-build]s to s5d 9 plans & proposals4 ,let ! contractors und]/& t all plans & computations are to be submitt$ to y\r eng9e]1 t all mat]ials & workman%ip w be submitt$ to y\r inspectors1 & t ! :ole /ructure is to be made subject to ! sup]vision ( a compet5t eng9e]1 & accept$ by him = y4 ,y w f9d at once1 t1 "u su* conditions1 all travell+ ag5ts & build]s ( *eap bridges w avoid y z a ?ief does ! light ( day4 ,y w h g5u9e proposals f responsible companies1 & _! bids %\ld be submitt$ to y\r eng9e]4 ,:5 y h made y\r *oice1 let ! contract be writt5 by y\r lawy]1 & h ! plans & specifications atta*$4 ,employ a compet5t eng9e] to inspect ! "w z x goes on2 & :5 x is done1 y w h a bridge :i* w be w>rant$ absolutely s\nd by ! be/ au?ority4 ,?is mode ( buy+ a bridge is v uncommon4 ,! ,a%tabula bridge1 x is /at$ 9 ! report ( ! committee ( ! ,ohio ,legislature appo9t$ to inve/igate t disa/]1 _h factors1--we c h>dly call !m factors ( safety1--9 "s p>ts z l[ z #a-f_/aj & #a-b_/aj1 su* factors ref]r+ to ! break+-weight2 & ev5 ^! factors 7 obta9$ by assum+ ! load z at re/1 & mak+ no all[ance = ! j> & %ock f a railroad tra9 9 motion4 ,well may ! commission]s say1 z !y d at ! end ( _! report1 ,! bridge 0 liable to g d[n at any "t dur+ ! la/ t5 ye>s "u ! loads t might at any "t be br\ght ^u x 9 ! ord9>y c\rse ( ! company's bus9ess1 & x is mo/ rem>kable t x did n soon] occur4 ,"o po9t always br\ght =w>d :5 an iron bridge breaks d[n1 is ! suppos$ det]ioration ( iron "u repeat$ /ra9+2 & we are gravely told t aft] a :ile all iron loses its fibre1 & becomes cry/all9e4 ,?is is "o ( ! my/]ies :i* "s p]sons conjure up at tol]ably regul> int]vals to cov] _! ignorance4 ,x is p]fectly well kn[n by eng9e]s ! _w ov]1 t ) good iron prop]ly us$1 no?+ ( ! k9d ev] takes place4 ,?is matt] us$ to be a favorite bone ( cont5tion among eng9e]s1 b x has long s9ce be5 laid ^u ! %elf4 ,no eng9e] at ! pres5t day ev] ?9ks ( x4 ,we h only to all[ ! prop] m>g9 = safety1 z our fir/-class build]s all d1 & ?is antiquat$ objection at once vani%es4 ,! examples ( ! long duration ( iron 9 l>ge bridges are num]\s & conclusive4 ,! ,niag>a-,falls railroad susp5sion bridge 0 c>efully inspect$ aft] tw5ty-five ye>s ( cont9u$ use "u frequ5t & heavy tra9s1 & n only 0 x impossible to detect by ! sev]e/ te/s any defect 9 ! wire ( ! cables1 b a piece ( x1 be+ ?r[n ^u ! floor1 curl$ up1 %[+ ! old k9k :i* ! iron _h :5 x 0 fir/ made1 & w\nd on ! reel4 ,! ,m5ai susp5sion bridge1 9 :i* #a1jjj tons ( iron h hung susp5d$ across an op5+ ( #fjj feet = sixty ye>s1 %[s no depreciation t ! mo/ rigid inspection c\ld detect4 ,iron rods1 rec5tly tak5 f an old bridge 9 ?is c\ntry1 h be5 c>efully te/$ aft] sixty ye>s ( use1 & f\nd to h lo/ no?+1 ei!r ( ! orig9al break+-/r5g?1 or ( ! orig9al ela/icity4 ,! "q is frequ5tly ask$1 ,does n extreme cold weak5 iron bridges8 ,to ?is1 x may be repli$1 t no iron bridge1 made by a reliable company1 has ev] %[n ! slighte/ indication ( any ?+ ( ! k9d1 ?\gh !y h be5 us$ = _m ye>s 9 ,russia1 ,norway1 ,sw$51 & ,canada1 & no?+ t we "k 9 reg>d to iron gives u any reason to suppose t any ?+ ( ! k9d ev] w happ54 ,b "h1 aga91 e ?+ turns ^u ! quality ( ! iron4 ,iron conta9+ phosphorus is cold-%ort1 or brittle :5 cold1 & w break quick] "u repeat$ & sudd5 %ocks 9 cold wea!r ?an :5 x is w>m4 ,) good iron1 prop]ly us$1 we ne$ h no fe> on ?is po9t4 ,! secur+ su* iron is a matt] to :i* ! utmo/ att5tion is paid by our fir/-class bridge-build+ firms1 b x is a matt] to :i* no att5tion is paid by ! build]s ( *eap bridges4 ,we might suppose t a p]son1 9 putt+ an insuffici5t am\nt ( iron into a bridge1 w\ld be c>eful to get ! be/ quality2 b exactly ! rev]se seems to be ! case1 on ! gr\nd1 p]haps1 t ! less ( a bad ?+ we h1 ! bett]4 ,_m p]sons1 9 build+ wood5 bridges1 take no pa9s to get iron rods :i* are suitable = su* "w1 b pur*ase :at is easie/ to be _h 9 ! m>ket1 & 9 _m cases nev] f9d t ! iron 0 bad until a bridge tumbles d[n4 ,!re are1 )\t ! slighte/ "q1 hundr$s ( bridges n[ 9 use 9 ?is c\ntry1 :i*1 z f> z m]e proportions & dim5sions g1 w\ld appe> to be entirely safe1 b :i*1 on acc\nt ( ! quality ( ! iron ) :i* !y are made1 are entirely unsafe2 & !re always w be1 z long z public (ficials pur*ase iron :i* !y "k no?+ ab\t1 to put into bridges4 ,:5 a bridge is f9i%$1 ! ord9>y exam9ations nev] detect ! quality ( ! iron2 s t ! wise rem>ks ( _m inspectors1 or ! op9ions ( ^? 9 *>ge ( ^! /ructures1 z to ! exact condition ( a bridge1 are ( little or no value4 ,we (t5 he> iron bridges condemn$1 :ile wood5 ones1 s call$1 are suppos$ to be free f defects4 ,x does n seem to occur to p]sons hold+ su* ideas1 t wood5 bridges rely j z mu* ^u ! /r5g? ( ! iron rods t tie ! timb]s toge!r1 z ^u ! timb]4 ,z a matt] ( fact1 :]e "o iron bridge falls1 a doz5 wood5 ones d ! same ?+4 ,"o v decid$ advantage :i* an iron bridge has ov] a wood5 "o1 is t we c make sure ( good iron 9 ! beg9n+1 & t we c also be sure t x does n decay2 :ile1 h[ev] good our timb] may be 9 ! beg9n+1 we nev] c be entirely sure ( its condition aft]w>ds4 ,!re are wood5 bridges n[ /&+ 9 ?is c\ntry1 all ! way f sixty to eighty ye>s old1 :i* are app>5tly z good z ev]2 :ile !re are o!rs1 n t5 ye>s old1 :i* are s rott5 z to be unfit = use4 ,x w n d to assume1 t1 because no defects are v evid5t 9 a wood5 bridge1 !re=e x has none4 ,:5 a wood5 bridge1 orig9ally made ( only fair mat]ial1 has be5 9 use "u railroad tra9s = tw5ty-five or ?irty ye>s1 & 9 a position :]e timb] w\ld naturally decay1 we are b\nd to suspect t bridge4 ,to assume su* a bridge to be all "r until we c prove x to be all wrong1 is n safe4 ,to assume a bridge to be all wrong until we c prove x to be all "r1 is a safe me?od1 ?\gh n a popul> "o4 ,any p]son :o has _h occasion to remove old wood5 bridges1 w recall h[ (t5 !y look v mu* worse ?an 0 anticipat$4 ,!re is "o defect 9 railway bridges :i* has (t5 l$ to ! mo/ fe>ful disa/]s1 & :i*1 )\t ! slighte/ "q1 c be almo/ entirely1 if n entirely1 remov$1 & at a mod]ate co/4 ,at lea/ half ! mo/ disa/r\s failures ( railroad bridges 9 ! ,unit$ ,/ates h be5 due to a defective sy/em ( floor+4 ,) a v l>ge proportion ( our bridges1 ! failure ( a rail1 ! break+ ( an axle1 or any ?+ :i* %all ?r[ ! tra9 f ! track1 is almo/ sure to be foll[$ by ! break+ d[n ( ! bridge4 ,! cross-ties are 9 _m cases v %ort1 & ! floor is proportion$ = a tra9 on & n (f ! rails4 ,:5 an eng9e on su* a floor leaves ! track1 x plunges (f ! ends ( ! cross-ties into ! op5 space betwe5 ! /r+]s & ! *ords1 & g5]ally wrecks ! bridge4 ,to prev5t ?is1 ! cross-ties %\ld be long & well support$1 & plac$ s close t a d]ail$ eng9e _c cut ?r\gh !m4 ,! track %\ld also be provid$ ) gu>d-timb]s well fa/5$1 & ! wid? betwe5 ! trusses %\ld be s great t ! :eels ( a d]ail$ tra9 w be /opp$ by ! gu>d-rail be=e ! side ( ! wide/ c> c /rike ! truss4 ,! importance ( a sub/antial floor sy/em has be5 v fully recogniz$ by ! railroad commission]s ( ,massa*usetts1 :o h rec5tly issu$ a v sugge/ive circul>1 accompani$ by num]\s examples ( track con/ruction = railway bridges4 ,if ?is circul> receives prop] att5tion1 x is sure to produce good results4 ,ano!r po9t :i* has (t5 be5 neglect$1 is mak+ suffici5t provision to resi/ ! =ce ( ! w9d4 ,a tornado1 su* z is n uncommon 9 ?is c\ntry1 w ex]t a =ce ( #dj p\nds p] squ>e foot1 :i* ^u ! side ( a wood5 bridge1 say ( #bjj feet span1 & #be feet high1 & bo>d$ up z _m bridges are1 w\ld am\nt to a lat]al ?ru/ ( no less ?an #ajj tons2 & ?is load w\ld be appli$ 9 ! wor/ possible mann]1 i4e41 9 a s]ies ( %ocks4 ,!re h be5 _m cases 9 ?is c\ntry :]e bridges h be5 bl[n d[n2 & a case rec5tly occurr$ :]e an iron railroad bridge ( #ahj feet span1 & #cj feet high1 & pres5t+ app>5tly almo/ no surface to ! w9d1 0 bl[n s mu* out ( l9e t ! track _h to be %ift$4 ,! rec5t t]rible disa/] at ! ,fir? ( ,tay 01 no d\bt1 due to ?is cause4 ,at ! "t ( ! ,t>iffville cata/rophe1 x 0 gravely /at$ at ! coron]'s inque/1 & by railroad (fic]s :o claim$ to "k ab\t su* ?+s1 t ! disa/] 0 caus$ by ! trem5d\s weight ( two locomotives :i* 7 c\pl$ toge!r1 & x 0 /at$ t "o eng9e w\ld h pass$ 9 safety2 & directly aft]w>ds ! sup]9t5d5t ( a prom95t railroad 9 ,new ,engl& issu$ an ord] =bidd+ two eng9es connect$ to pass ov] any iron bridges4 ,x is all v well = a company to issue su* an ord]1 s f> z x may give ! public to und]/& t x is det]m9$ to use e precaution aga9/ disa/]2 b su* an ord] may h ! effect ( creat+ a di/ru/ :i* really ought n to exi/4 ,if a railway bridge is n entirely safe = two eng9es1 x is c]ta9ly entirely unsafe = "o eng9e & ! tra9 foll[+2 ! only sav+ 9 weight by tak+ (f "o eng9e be+ ! diff]5ce betwe5 ! weight ( t eng9e & ! weight ( ! c>s t w\ld occupy ! same room4 ,= example1 a bridge ( #bjj feet span w weigh #a1ejj p\nds p] l9eal foot4 ,an eng9e & its t5d] w weigh #fj tons 9 a l5g? ( #ej feet1 & a load$ freight-tra9 may easily weigh #b_/c ( a ton p] l9eal foot4 ,! total weight ( ! span1 ) two eng9es1 & ! re/ ( ! bridge cov]$ ) load$ freight-c>s1 w\ld ?us be #cbj tons4 ,if we take (f "o eng9e1 & fill its place ) c>s1 we take (f #fj tons1 & put 9 its place #cc tons2 i4e41 we remove #bg tons1 or j ab\t #a_/ab ( ! work+-load4 ,tak+ (f a l>ge "p ( ! work+-load1 h[ev]1 is tak+ (f a v small "p ( ! break+-load2 ) a factor ( safety ( six1 = example1 tak+ (f #a_/ab ( ! work+-load is tak+ (f less ?an #a_/gj ( ! break+-load4 ,an ord]1 !re=e1 l t above1 c only be ( use :5 ! work+-load & ! break+-load are s ne>ly alike t ! actual load is a dang]\s "o3 t is :5 ! bridge is unfit = any traffic :atev]2 s t1 if su* an ord] 0 really ne$$1 x w\ld1 9 itself1 be1 9 ! eyes ( an eng9e]1 a condemnation ( ! bridge4 ,hav+ se5 some?+ ( ! /ructures :i* require inspect+1 let u n[ see :at k9d ( inspection we h 9 ?is c\ntry1 & ! result ( x2 & let u also see ! inspection :i* we might h1 & ! results t might be produc$4 ,look+ fir/ at railroad bridges1 x might be suppos$ t no "o c\ld be s mu* int]e/$ 9 keep+ su* /ructures 9 good ord] z ! companies :i* own ^? bridges1 & :i* h ! bills to pay 9 case ( disa/]4 ,?is is1 ( c\rse1 s2 b1 9 spite ( ! fact1 ! ,a%tabula bridge broke d[n1 on "o ( ! be/ manag$ l9es 9 ! c\ntry1 & co/ ! company ov] half a million doll>s 9 damages4 ,no railroad bridge ev] broke d[n1 :i* ! own]s 7 n int]e/$ 9 keep+ safe2 b !re is always a desire to put (f incurr+ l>ge exp5ses until ! la/ mom5t1 & ?us weak bridges are v (t5 let g too long4 ,a %ort "t s9ce1 ! sup]9t5d5t ( a l>ge railroad /at$ pla9ly be=e a legislative committee1 t _m ( ! small] roads 7 n safe to run ov]1 b t su* roads 7 hav+ a h>d "t1 & c\ld n af=d to keep _! track & bridges 9 a safe condition4 ,dur+ ! pa/ t5 ye>s ov] two hundr$ railroad bridges 9 ! ,unit$ ,/ates h brok5 d[n4 ,^! bridges 7 all kept "u su* inspection z ! railroad companies own+ !m consid]$ suffici5t1 or su* z !y c\ld af=d2 b ei!r ! sup]vision 0 defective1 or ! companies kn[+ly cont9u$ ! use ( unsafe bridges1 & ?is fault has by no means be5 conf9$ to ! small] & poor] roads4 ,x w\ld seem1 !re=e1 t inspection by ! companies !mselves has n be5 suffici5t4 ,x c]ta9ly has n be5 en\gh to prev5t two hundr$ disa/]s 9 t5 ye>s4 ,x is ! cu/om 9 sev]al ( ! ,unit$ ,/ates to ma9ta9 :at is t]m$ a railroad commission4 ,! orig9al int5tion seems to h be5 = ^! commissions to keep ! railroads "u "s k9d ( inspection1 & 9 "s way to assi/ 9 settl+ any que/ions t might arise betwe5 diff]5t companies1 & betwe5 railroad companies & ! public4 ,z f> z we c judge by ! results produc$1 9 ! ,/ates :]e ^! commissions h be5 e/abli%$1 we c h>dly pron\nce !m ( any v great importance4 ,9 _m ,/ates1 x is v c]ta91 t1 9 reg>d to matt]s ( inspection1 ! "w ( ^! bo>ds has be5 simply a f>ce2 & x c\ld h>dly be o!rwise 9 a ,/ate :i* pays its commission]s only #a1jjj sal>y1 or1 worse yet1 z 9 "s cases1 only #ejj4 ,add to ?is1 t 9 _m cases ! appo9tm5ts h be5 purely political ones1 & we c see ! absurdity ( expect+ any results ( value4 ,we %\ld h>dly suppose t ?ree m51 9 _m cases entirely unacqua9t$ ) me*anical matt]s1 c\ld by rid+ ov] a railroad once or twice a ye>1 occasionally gett+ out to exam9e ! pa9t on ! outside ( ! bo>ds1 :i* conceal a truss f view1 judge v correctly ( ! ela/ic limit ( ! iron rods :i* !y h nev] se51 & ( :i* !y d n ev5 "k ! exi/5ce4 ,= ample pro( ( ! utt] ineffici5cy ( ! pres5t sy/em1 we h only to comp>e ! reports ( ! railroad commission]s 9 almo/ any ,/ate1 ) ! actual condition ( ! /ructures describ$4 ,9 "o ,/ate a late annual report cov]s a :ole railroad ) ! rem>k1 ,all ( ! bridges on ?is l9e are 9 excell5t ord]2 & yet !re 7 at t v "t1 & are n[1 on t road1 sev]al l>ge wood5 bridges ) a factor ( safety ref]r$ to ! break+-weight ( n ov] two "u a fair load1 assum+ ! iron rods to be ( ! v be/ mat]ial1--a po9t ^u :i* !re is no evid5ce :atev]4 ,!re is1 9 fact1 no diff]5ce :i* any ord9>y inspection w\ld detect betwe5 ^! bridges z !y /& to-day1 & ! ,t>iffville bridge z x /ood ! day be=e x fell4 ,9 ano!r ,/ate1 an iron bridge is 9 use "u heavy tra9s1 :i* has a factor ( only #b-a_/b in/ead ( #f1 & yet ! ,/ate report pron\nces x an excell5t /ructure & a cr$it to ! railroad company1 :i* recklessly all[s its tra9s to pass ov] x4 ,9 yet ano!r ,/ate1 ! commission]s 9 #ahgd report$ t a c]ta9 bridge %\ld be remov$2 & ?is 0 q correct1 z x 0 an em95tly unsafe bridge4 ,9 #ahge !y sugge/$ ! same ?+ aga94 ,9 #ahgf !y say1 ,?is bridge mu/ be rebuilt ! com+ spr+4 ,9 #ahgg !y aga9 report$1 ,?is bridge mu/ be rebuilt be=e ! spr+ op5s4 ,x is old1 & w n be safe = ! passage ( tra9s ov] x1 if ! ice or fre%et %\ld take away ! tempor>y tre/les1 :i* n[ 9 a great measure support ! truss4 ,a ye> lat] ?an t1 9 #ahgh1 a public prote/ 0 made aga9/ ! fur!r use ( t bridge1 z ! l[] *ords 7 rott51 brok51 pull$ ap>t1 & ! only ?+ t held x up 0 a tre/le1 liable at any "t to be knock$ out by ! ice2 & yet1 aft] all ?is1 9 reply to ! prote/1 ! commission]s repli$ t !y _h j te/$ ! bridge by runn+ an eng9e ov] x1 & pron\nc$ x safe = ! pres5t1 :atev] t may mean4 ,n[1 j h[ x 0 t ?is bridge1 :i* 0 old1 rott51 & worn out1 :i* ! commission]s !mselves _h condemn$ = f\r successive ye>s1 :i* !y _h said two ye>s be=e mu/ be rebuilt ! com+ spr+1 & :i* reli$ entirely ^u a tre/le liable at any "t to be c>ri$ away1 _h sudd5ly become safe = ! pres5t1 is n pla9 to see4 ,evid5tly su* inspection z ?is is ( no value4 ,x is exactly ?is utt]ly incompet5t & di%one/ inspection1 ?is guess+ t a bridge w /& until x falls1 t lies at ! bottom ( half ! disa/]s 9 ! c\ntry4 ,x is "u exactly su* inspection t ^? wret*$ traps1 ! ,a%tabula & ,t>iffville bridges1 fell1 & kill$ ov] "o hundr$ p4 ,no wond] t railroad (ficials h an undisguis$ contempt = ,/ate inspection4 ,:ile 9 a few ,/ates ! inspection is n q s bad z t ref]r$ to1 z a g5]al ?+ x is no bett]2 & we h no "r to expect any ?+ bett] "u ! pres5t sy/em4 ,! ,/ate inspection :i* we h _h ?r\gh\t ?is c\ntry has n prev5t$ ! break+ d[n ( "o hundr$ bridges 9 ! pa/ t5 ye>s4 ,tw5ty-five ,/ates h railroad commissions2 b 9 n9e ( !m ! commission consi/s ( only a s+le man1 :o1 9 "s cases1 is paid only #ejj a ye>4 ,a ,/ate c pay #ejj a ye> = hav+ its bridges inspect$1 & x w get su* s]vice z nev] did & nev] w prev5t a disa/]2 or x c pay a good price = compet5t inspection1 :i* w be wor? t5 times ! money to ! ,/ate4 ,! money :i* ! ,lake ,%ore ,railroad paid 9 damages = ! ,a%tabula disa/] alone1 w\ld h employ$ p]man5tly six m5 at #e1jjj a ye> ea*1 & a hundr$ lives w\ld h be5 sav$ besides4 ,) reg>d to highway bridges1 we are1 if possible1 ev5 worse (f ?an 9 reg>d to railway bridges2 = 9 ! case ( su* /ructures1 nei!r ! own]s nor ! ,/ate make any pret5ce at inspection4 ,x is impossible to say h[ _m highway bridges h brok5 d[n dur+ ! pa/ t5 ye>s1 b x is e/imat$ by bridge-build]s t ! numb] _c be less ?an two hundr$4 ,?is is1 no d\bt1 f> )9 ! tru?2 & by f> ! l>g] "p ( ^! /ructures are n old wood5 bridges1 b are new bridges ( iron4 ,if we knew positively t 9 j six mon?s a t]rible disa/] w\ld occur "u ! pres5t sy/em ( bridge inspection1 & knew also1 t1 by a bett] sy/em1 su* disa/] w\ld c]ta9ly be prev5t$1 x is possible t a *ange might be made4 ,we "k t a prop] me?od ( build+ & inspect+ bridges w\ld c]ta9ly h prev5t$ ! disa/]s at ,a%tabula1 ,t>iffville1 & ,dixon4 ,we "k t ! inspection :i* ^? bridges receiv$1 did n prev5t ?ree ( ! mo/ fe>ful disa/]s ! c\ntry has ev] se54 ,admitt+1 n[1 t /ructures s important to ! public safety z bridges1 bo? ^u roads & railroads1 ought to be kept "u rigid inspection & control1 & t no sy/em at pres5t exi/+ has be5 able to prev5t ! mo/ fe>ful cata/rophes1 :at %all we d8 ,directly aft] ! ,a%tabula disa/]1 ! ,ohio legislative committee1 appo9t$ to inve/igate t affair1 pres5t$ to ! ,legislature a bill1 ,to secure great] safety = public travel ov] bridges1 9 :i* 0 pla9ly specifi$ ! loads = :i* all bridges %\ld be proportion$1 ! maximum /ra9s to :i* ! iron %\ld be subject$1 & a me?od = inspect+ ! plans ( all bridges be=e build+1 & ! bridges !mselves dur+ & aft] con/ruction4 ,! gov]nor1 ) ! cons5t ( ! ,s5ate1 0 to appo9t ! inspector = a t]m ( five ye>s at a sal>y n exce$+ #c1jjj a ye>1 su* inspector to pass a satisfactory exam9ation be=e a committee ( ! ,am]ican ,society ( ,civil ,eng9e]s1 !mselves practical exp]ts 9 bridge con/ruction1 & he 0 also to take a suitable oa? = ! fai?ful p]=mance ( 8 duty4 ,?is bill nev] became a law4 ,an appropriation 0 made = a %ort "t to pay = c]ta9 exam9ations1 & !re ! matt] /opp$4 ,! committee ( ! ,am]ican ,society ( ,eng9e]s 7 n agre$ ^u ?is matt]4 ,messrs4 ,james ,b4 ,eads & ,*>les ,%al] ,smi? sugge/$ ! appo9tm5t 9 ea* ,/ate ( an exp]t1 to :om all plans %\ld be submitt$1 & by :om all "w %\ld be inspect$1--su* exp]t to h be5 exam9$ & approv$ by ! ,am]ican ,society ( ,civil ,eng9e]s4 ,! inspector 0 also to visit ! sc5e ( e accid5t1 s call$1 & to asc]ta91 z f> z possible1 ! cause4 ,messrs4 ,t4 ,c4 ,cl>ke & ,julius ,w4 ,adams believ$1 t1 9 ! pres5t /ate ( public op9ion1 ! above me?od w\ld be impracticable1 & fe>$1 t1 if inspectors 7 appo9t$1 x w\ld be by political influ5ce1 & t ! result w\ld be worse ?an at pres5t1 z ! inspectors w\ld be ineffici5t1 & yet1 to a great ext5t1 w\ld relieve ! own]s ( bad bridges f legal responsibility4 ,!y held t ! be/ t c\ld be done w\ld be to provide means1 9 case ( disa/]1 to fix pla9ly ! responsibility1 & recomm5d$1 ,fir/1 t ! /&>d = /r5g? fix$ by ! ,society %\ld be ! legal /&>d2 &1 9 case x %\ld be f\nd t any bridge 0 ( less /r5g? ?an ?is1 x %\ld be tak5 z prima facie evid5ce ( neglect on ! "p ( ! own]s4 ,second1 t no bridge %\ld be op5$ to ! public until a plan giv+ all dim5sions1 /ra9s1 & loads1 sworn to by ! design]s & mak]s1 & atte/$ by ! corporation hav+ control ( x1 _h be5 deposit$ ) ! ,am]ican ,society2 & fur!r1 t ! pr9cipal pieces ( iron 9 ! bridge %\ld be /amp$ ) ! "n ( ! mak]1 place ( manufacture1 & date4 ,messrs4 ,a4 ,p4 ,boll] & ,*>les ,macdonald look$ r t[>d effect+ ! desir$ result by s direct+ public s5tim5t by keep+ ! correct /&>d = bridges be=e x1 t x w\ld ev5tually compel ! passage ( ! necess>y laws4 ,:e!r x is possible1 9 ?is c\ntry1 to make an appo9tm5t dep5d5t purely ^u hone/y & capacity1 & free f political influ5ce1 may well be d\bt$4 ,no compet5t eng9e] w\ld be will+ to accept a position :i* w\ld place ^u him s great a responsibility1 except "u a v c>efully devis$ plan4 ,a v consid]able =ce ( inspectors w\ld be requir$ to c>ry out a sy/em :i* %\ld produce ! desir$ result4 ,! am\nt ( "w to be done at ! comm5cem5t w\ld be v great1 z no prop] inspection has ev] be5 made ( ! great] "p ( ! bridges 9 ! c\ntry1 ( :i* ! numb] is v l>ge4 ,if any su* plan z above sugge/$ %\ld be f\nd feasible1 ! inspectors %\ld h 9 _! possession a complete set ( plans ( e bridge ( importance 9 ! ,/ate1 ) all ! computations ( its /r5g?1 & z complete a hi/ory ( ea* /ructure f its comm5cem5t z c be made up1 all ?is to be supplem5t$ by p]iodic exam9ations4 ,if1 f su* records1 we f9d t a bridge 0 made ( ord9>y gre5 timb] tw5ty-five ye>s ago1 & t x has be5 gett+ rott5 ev] s9ce2 t x has rods ( common m]*ant iron t 7 b\ght by "s p]son1 n specially acqua9t$ ) ! bus9ess1 f an unkn[n firm1--we _h bett] pull x d[n be=e x falls4 ,if1 f su* records1 we f9d an iron bridge built tw5ty-five ye>s ago by an unkn[n company1 ) iron1 at be/1 ( a d\btful quality1 & hav+ a factor ( ?ree or f\r = ! roll+-/ock & spe$s ( tw5ty ye>s ago1 in/ead ( a factor ( six = ! roll+-/ock & spe$s ( to-day1 we _h bett] remove t bridge be=e x removes itself4 ,su* a record w\ld be ! prop]ty ( ! ,/ate1 always accessible to any "o1 & w\ld be h&$ d[n1 s t ! k ( "o p]son w\ld n expire ) 8 t]m ( (fice4 ,no bridge %\ld be erect$ 9 any ,/ate )\t fir/ submitt+ ! plans to ! inspector1 & receiv+ 8 approval1 & deposit+ ) him a complete set ( ! plans & computations = ! "w4 ,by ?is approval is n meant t ! inspector is m]ely to give a favorable op9ion z to ! plan1 b t he is to f9d1 z a matt] ( fact1 :e!r ! propos$ dim5sions & proportions are su* z w make a safe bridge--& j :at a safe bridge is1 c be pla9ly def9$ by law1 z x is 9 ,europe1 & z x has be5 propos$ by ! ,am]ican ,society ( ,civil ,eng9e]s4 ,= example1 if ! law says t an iron railway bridge ( #ajj feet span %all be proportion$ to c>ry a load ( #c1jjj p\nds p] l9eal foot besides its own weight1 & t1 ) su* a load1 no "p %all be /ra9$ by m ?an #aj1jjj p\nds p] in*1 all ! inspector has to d is to g ov] ! figures1 & see t ! dim5sions giv5 on ! plan are su* z w enable ! bridge to c>ry ! load )\t exce$+ ! specifi$ /ra9s4 ,:5 ! "w is erect$1 ! inspection mu/ %[ t ! plan has be5 exactly c>ri$ out1 t ! details are good1 & prop] evid5ce ( ! quality ( ! mat]ial us$ %\ld also be giv54 ,su* inspection z ?is w\ld at once prev5t ! erection ( bridges l ^? at ,a%tabula & ,t>iffville1 & w\ld save ! public f su* traps z ^? t fell at ,dixon & at ,grovel&4 ,p]haps ! mo/ difficult ?+ to d w be to get satisfactory evid5ce 9 reg>d to ! bridges t h be5 = a consid]able "t 9 use1 & ( :i* we d n "k ! hi/ory4 ,?is w be especially true 9 reg>d to ! wood5 bridges1 ( :i* !re are s _m ab\t ! c\ntry4 ,n only is x v difficult to be sure ( ! exact condition ( ! timb]1 b x is equally h>d to tell any ?+ ab\t ! iron4 ,! ,t>iffville bridge fell on acc\nt ( defective iron1 & ! defect 0 ( su* a nature z to defy any ord9>y inspection4 ,:at d we "k to-day ( ! quality ( ! iron rods 9 any wood5 bridge 9 ,massa*usetts8 ,x is v d\btful if ! be/ inspection we h 9 ! ,unit$ ,/ates at ! pres5t "t w\ld h f\nd any defect s evid5t 9 ! ,t>iffville bridge z to condemn x z unfit = ! passage ( tra9s4 ,!re are hundr$s ( exactly su* bridges all ov] ,new ,engl&1 z f> z we c tell by ! be/ inspection we n[ h1 made on ! same plan1 ) no m mat]ial1 & ( :i* we "k j z little ( ! quality ( ! iron z we did 9 ! ,t>iffville bridge4 ,( c\rse we _c expect to get a p]fect sy/em all at once4 ,any plan :i* might be propos$ w\ld1 no d\bt1 be f\nd m or less defective at fir/4 ,we c h>dly get a sy/em worse ?an ! "o we n[ h1 :i* all[s =ty bridges to break d[n e ye>4 ,we may get a bett] "o4 ,to make ! public see ! ne$ ( su* a sy/em is ! fir/ /ep to be tak54 99 99 99 99 99 ,,lee ,,& ,,%ep>d',s ,,popul> ,,h&books4 ,price1 ea*1 9 clo?1 #ej c5ts1 except :5 o!r price is giv54 ,=gott5 ,mean+s2 or an ,h\r ) a ,diction>y4 ,by ,,alfr$ ,,waites1 au?or ( ,hi/orical ,/ud5t's ,manual4 ,h&book ( ,elocution ,simplifi$4 ,by ,,walt] ,k4 ,,fobes1 ) an ,introduction by ,,george ,m4 ,,bak]4 ,h&book ( ,engli% ,synonyms4 ,) an ,app5dix1 %[+ ! ,correct ,use ( ,prepositions2 also a ,collection ( ,=eign ,phrases4 ,by ,,loomis ,j4 ,,campbell4 ,h&book ( ,conv]sation4 ,its ,faults & its ,graces4 ,compil$ by ,,&rew ,p4 ,,peabody1 ,d4 ,d41 ,,ll4 ,d4 ,compris+3 7#a7 ,dr4 ,,peabody',s ,address2 7#b7 ,mr4 ,,tr5*',s ,lecture2 7#c7 ,mr4 ,,p>ry ,,gwynne',s ,a ,^w to ! ,wise2 or1 ,h9ts on ! ,curr5t ,improprieties ( ,expression 9 ,read+ & ,writ+2 7#d7 ,mi/akes & ,improprieties ( ,speak+ & ,writ+ ,correct$4 ,h&book ( ,punctuation & o!r ,typographical ,matt]s4 ,= ! ,use ( ,pr9t]s1 ,au?ors1 ,tea*]s1 & ,s*ol>s4 ,by ,,m>%all ,t4 ,,bigel[1 ,corrector at ! ,univ]sity ,press1 ,cambridge1 ,mass4 ,h&book ( ,blund]s4 ,design$ to prev5t #a1jjj common blund]s 9 writ+ & speak+4 ,by ,,h>lan ,h4 ,,ball>d1 ,a4 ,m41 ,pr9cipal ( ,l5ox ,academy1 ,l5ox1 ,mass4 ,brok5 ,engli%4 ,a ,fr5*man's ,/ruggle 9 ! ,engli% ,language4 ,in/ructive z a h&book ( ,fr5* conv]sation4 ,by ,pr(essor ,e4 ,c4 ,,dubois4 ,beg9n+s ) ! ,microscope4 ,a work+ h&book conta9+ simple in/ructions 9 ! art & me?od ( us+ ! microscope1 & prep>+ articles = exam9ation4 ,by ,,walt] ,p4 ,,manton4 ,field ,botany4 ,a ,h&book = ! ,collector4 ,conta9+ in/ructions = ga!r+ & pres]v+ ,plants1 & ! =mation ( an ,h]b>ium4 ,also complete in/ructions 9 ,leaf ,photography1 ,plant ,pr9t+1 & ! ,skeletoniz+ ( ,leaves4 ,by ,,walt] ,p4 ,,manton4 ,taxid]my )\t a ,tea*]4 ,compris+ a complete manual ( in/ructions = ,prep>+ & ,pres]v+ ,birds1 ,animals1 & ,fi%es1 ) a *apt] on ,hunt+ & ,hygi5e2 toge!r ) in/ructions = ,pres]v+ ,eggs1 & ,mak+ ,skeletons1 & a numb] ( valuable recipes4 ,by ,,walt] ,p4 ,,manton4 ,insects4 ,h[ to ,cat* & h[ to ,prep>e !m = ! ,cab9et4 ,a ,manual ( ,in/ruction = ! ,field-,naturali/4 ,by ,w4 ,p4 ,,manton4 ,:at is to be ,done8 ,a ,h&book = ! ,nurs]y1 ) ,useful ,h9ts = ,*ildr5 & ,adults4 ,by ,,rob]t ,b4 ,,dixon1 ,m4 ,d4 ,:irlw9ds1 ,cyclones1 & ,tornadoes4 ,by ,,william ,,morris ,,davis1 ,in/ructor 9 ,h>v>d ,college4 ,illu/rat$4 ,mi/akes 9 ,writ+ ,engli%1 & ,h[ to ,avoid ,!m4 ,= ! use ( all :o ,tea*1 ,write1 or ,speak ! language4 ,by ,,m>%all ,t4 ,,bigel[4 ,sold by all booksell]s1 & s5t by mail1 po/paid1 on receipt ( price4 ,,lee ,,& ,,%ep>d ,publi%]s ,bo/on 99 99 99 99 99 ,,lee ,,& ,,%ep>d',s ,,popul> ,,h&books ,price1 ea*1 9 clo?1 #ej c5ts1 except :5 o!r price is giv54 ,w>r+ton's ,manual4 ,a ,manual = ! ,in=mation ( ,(fic]s & ,memb]s ( ,legislatures1 ,conv5tions1 ,societies1 etc41 9 ! practical gov]n+ & memb]%ip ( all su* bodies1 accord+ to ! ,p>liam5t>y ,law & ,practice 9 ! ,unit$ ,/ates4 ,by ,w4 ,s4 ,,rob9son 7,w>r+ton74 ,practical ,boat-,sail+4 ,by ,,d\glas ,,fraz>4 ,classic size1 #a4jj4 ,) num]\s diagrams & illu/rations4 ,h&book ( ,wood ,engrav+4 ,) practical in/ructions 9 ! art1 = p]sons wi%+ to le>n )\t an in/ructor4 ,by ,,william ,a4 ,,em]son4 ,illu/rat$4 ,price #a4jj4 ,five-,m9ute ,recitations4 ,select$ & arrang$ by ,,walt] ,k4 ,,fobes4 ,five-,m9ute ,declamations4 ,select$ & arrang$ by ,,walt] ,k4 ,,fobes4 ,five-,m9ute ,read+s = ,"y ,ladies4 ,select$ & adapt$ by ,,walt] ,k4 ,,fobes4 ,educational ,psy*ology4 ,a ,treatise = ,p>5ts & ,educators4 ,by ,,l\ise ,,p>sons ,,hopk9s1 ,sup]visor 9 ,bo/on ,public ,s*ools4 ,! ,nation 9 a ,nut%ell4 ,a ,rapid ,outl9e ( ,am]ican ,hi/ory4 ,by ,,george ,,makepeace ,,t[le4 ,engli% ,synonymes ,discrim9at$4 ,by ,,ri*>d ,,:ately1 ,d4 ,d41 ,ar*bi%op ( ,dubl94 ,a new edition4 ,h9ts on ,writ+ & ,spee*-mak+4 ,by ,,?omas ,,w5twor? ,,higg9son4 ,ari?metic = ,"y ,*ildr54 ,be+ a s]ies ( ,ex]cises exemplify+ ! mann] 9 :i* ,ari?metic %\ld be taught to "y *ildr54 ,by ,,horace ,,grant4 ,am]ican ,edition4 ,edit$ by ,,will>d ,,small4 ,bridge ,disa/]s 9 ,am]ica4 ,! ,cause & ! ,rem$y4 ,by ,pr(4 ,,george ,l4 ,,vose4 ,a ,few ,?\ghts = a ,"y ,man4 ,by ,,horace ,,mann4 ,a new ,edition4 ,h&book ( ,debate4 ,! ,"* ( ,julius ,cs>4 ,adapt$ f ,j4 ,,%]idan ,,kn[les4 ,arrang$ = ,practice 9 ,speak+1 = ,debat+ ,clubs1 & ,classes 9 ,public & ,private ,s*ools4 ,sold by all booksell]s1 & s5t by mail1 po/paid1 on receipt ( price4 ,,lee ,,& ,,%ep>d ,publi%]s ,bo/on 99 99 99 99 99 ,,lee ,,& ,,%ep>d',s ,,popul> ,,h&books4 ,price1 ea*1 9 clo?1 #ej c5ts1 except :5 o!r price is giv54 ,ex]cises = ! ,improvem5t ( ! ,s5ses4 ,= ,"y ,*ildr54 ,by ,,horace ,,grant1 au?or ( ,ari?metic = ,"y ,*ildr54 ,edit$ by ,,will>d ,,small4 ,h9ts on ,language 9 connection ) ,sight-,read+ & ,writ+ 9 ,prim>y & ,int]m$iate ,s*ools4 ,by ,s4 ,,ar?ur ,,b5t1 ,a4 ,m41 ,sup]9t5d5t ( ,public ,s*ool1 ,cl9ton1 ,mass4 ,! ,hunt]'s ,h&book4 ,conta9+ li/s ( provisions & camp p>aph]nalia1 & h9ts on ! fire1 cook+ ut5sils1 etc42 ) approv$ receipts = camp-cook]y4 ,by ,,an ,,old ,,hunt]4 ,univ]sal ,phonography2 or1 ,%or?& by ! ,all5 ,me?od4 ,a self-in/ructor4 ,by ,g4 ,g4 ,,all54 ,h9ts & ,helps = ^? :o ,write1 ,pr9t1 or ,read4 ,by ,b4 ,,drew1 pro(-read]4 ,pron\nc+ ,h&book ( ,?ree ,?\s& ,words (t5 ,mispron\nc$4 ,by ,r4 ,,s\le & ,l4 ,j4 ,,campbell4 ,%ort ,/udies ( ,am]ican ,au?ors4 ,by ,,?omas ,,w5twor? ,,higg9son4 ,! ,/>s & ! ,e>?2 or1 ,?\ghts ^u ,space1 ,"t1 & ,et]nity4 ,) an introduction by ,,?omas ,,hill1 ,d4 ,d41 ,,ll4 ,d4 ,h&book ( ! ,e>?4 ,natural ,me?ods 9 ,geography4 ,by ,,l\isa ,,p>sons ,,hopk9s1 tea*] ( ,normal ,me?ods 9 ! ,swa9 ,free ,s*ool1 ,new ,b$=d4 ,natural-,hi/ory ,plays4 ,dialogues & ,recitations = ,s*ool ,exhibitions4 ,by ,,l\isa ,p4 ,,hopk9s4 ,! ,telephone4 ,an acc\nt ( ! ph5om5a ( ,electricity1 ,magnetism1 & ,s\nd1 ) directions = mak+ a speak+-telephone4 ,by ,pr(essor ,a4 ,e4 ,,dolbe>4 ,lessons on ,mann]s4 ,by ,,edi? ,e4 ,,wigg94 ,wat] ,analysis4 ,a ,h&book = ,wat]-,dr9k]s4 ,by ,g4 ,l4 ,,au/91 ,m4 ,d4 ,h&book ( ,light ,gymna/ics4 ,by ,,lucy ,b4 ,,hunt1 in/ructor 9 gymna/ics at ,smi? 7female7 ,college1 ,nor?ampton1 ,mass4 ,! ,p>lor ,g>d5]4 ,a ,treatise on ! ,h\se-,culture ( ,ornam5tal ,plants4 ,by ,,cornelia ,j4 ,,r&olph4 ,) illu/rations4 ,sold by all booksell]s1 & s5t by mail1 po/paid1 on receipt ( price4 ,,lee ,,& ,,%ep>d ,publi%]s ,bo/on 99 99 99 99 99 ,a ,,popul> ,,hi/ory ,,( ,,our ,,c\ntry ,,"y ,,folks' ,hi/ory ( ! ,unit$ ,/ates ,,by ,,?os4 ,,w5twor? ,,higg9son4 ,squ>e #afmo4 #chj pp4 ,) ov] #ajj ,illu/rations4 ,price #a4ej4 ,! !ory ( ! book c be briefly /at$2 x is1 t ,am]ican ,hi/ory is 9 itself "o ( ! mo/ attractive ( all subjects1 & c be made int]e/+ to old & "y by be+ pres5t$ 9 a simple1 cle>1 & graphic way4 ,9 ?is book only su* names & dates are introduc$ z are necess>y to secure a cle> & def9ite ?read ( connect$ incid5t 9 ! m9d ( ! read]2 & ! space ?us sav$ is devot$ to illu/rative traits & incid5ts1 & ! details ( daily liv+4 ,by ?is means x is believ$ t mu* m c be convey$1 ev5 ( ! philosophy ( hi/ory1 ?an :]e ?is is ov]laid & hidd5 by a mass ( m]e /ati/ics4 ,compact1 cle>1 & accurate4444 ,?is unpret5d+ little book is ! be/ g5]al hi/ory ( ! ,unit$ ,/ates we h se54--,! ,nation4 ,! book is s writt5 t e *ild old en\gh to read hi/ory at all w und]/& & l x1 & p]sons ( ! fulle/ in=mation & pure/ ta/e w admire x4--,bo/on ,daily ,adv]tis]4 ,x is m>vel\s to note h[ happily ,mr4 ,higg9son1 9 secur+ an amaz+ compactness by 8 cond5sation1 has avoid$ alike sup]ficiality & dullness4--,bo/on ,transcript4 ,,lee ,,%ep>d ,publi%]s ,bo/on 99 99 99 99 99 ,,by ,,george ,l4 ,,vose ,a ,,manual ,,= ,,railroad ,,eng9e]s ,,& ,,eng9e]+ ,,/ud5ts #afe ,woodcuts & #ca l>ge ,plates4 ,clo?4 #hvo4 #ab4ej4 ,,! ,,same 9 two volumes4 ,clo?4 #ae4jj4 ,volumes sold sep>ately3 ,text #f4jj1 ,plates #i4jj4 ,,elem5t>y ,,c\rse ,,( ,,geometrical ,,draw+ ,) #ch maps4 ,oblong ,folio4 ,clo?4 ,net1 #e4jj4 ,a ,,sket* ,,( ,,! ,,life ,,& ,,works ,,( ,,george ,w4 ,,:i/l]1 ,,civil ,,eng9e] #hvo4 ,clo?4 #a4jj4 ,,bridge ,,disa/]s ,,9 ,,am]ica--,,! ,,cause ,,& ,,! ,,rem$y ,h&book size4 ,clo?4 #ej c5ts4