industrial biography-第28章

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evidence　on　the　trial　of　Neilson's　patent　in　1839；　but　the　invention

does　not　appear　to　have　been　perfected　by　him。

　。。。＇



The　construction　of　a　bridge　of　iron　was　an　entirely　new　idea。　　An

attempt　had　indeed　been　made　at　Lyons；　in　France；　to　construct　such　a

bridge　more　than　twenty　years　before；　but　it　had　entirely　failed；　and

a　bridge　of　timber　was　erected　instead。　　It　is　not　known　whether　the

Coalbrookdale　masters　had　heard　of　that　attempt；　but；　even　if　they

had；　it　could　have　been　of　no　practical　use　to　them。



Mr。　Pritchard；　an　architect　of　Shrewsbury；　was　first　employed　to

prepare　a　design　of　the　intended　structure；　which　is　still　preserved。

Although　Mr。　Pritchard　proposed　to　introduce　cast…iron　in　the　arch　of

the　bridge；　which　was　to　be　of　120　feet　span；　it　was　only　as　a　sort

of　key；　occupying　but　a　few　feet　at　the　crown　of　the　arch。　　This

sparing　use　of　cast　iron　indicates　the　timidity　of　the　architect　in

dealing　with　the　new　materialhis　plan　exhibiting　a　desire　to　effect

a　compromise　between　the　tried　and　the　untried　in

bridge…construction。　　But　the　use　of　iron　to　so　limited　an　extent；　and

in　such　a　part　of　the　structure；　was　of　more　than　questionable

utility；　and　if　Mr。　Pritchard's　plan　had　been　adopted；　the　problem　of

the　iron　bridge　would　still　have　remained　unsolved。



The　plan；　however；　after　having　been　duly　considered；　was　eventually

set　aside；　and　another；　with　the　entire　arch　of　cast…iron；　was

prepared　under　the　superintendence　of　Abraham　Darby；　by　Mr。　Thomas

Gregory；　his　foreman　of　pattem…makers。　　This　plan　was　adopted；　and

arrangements　were　forthwith　made　for　carrying　it　into　effect。　　The

abutments　of　the　bridge　were　built　in　1777…8；　during　which　the

castings　were　made　at　the　foundry；　and　the　ironwork　was　successfully

erected　in　the　course　of　three　months。　　The　bridge　was　opened　for

traffic　in　1779；　and　proved　a　most　serviceable　structure。　　In　1788　the

Society　of　Arts　recognised　Mr。　Darby's　merit　as　its　designer　and

erector　by　presenting　him　with　their　gold　medal；　and　the　model　of　the

bridge　is　still　to　be　seen　in　the　collection　of　the　Society。　　Mr。

Robert　Stephenson　has　said　of　the　structure：　　〃　If　we　consider　that

the　manipulation　of　cast…iron　was　then　completely　in　its　infancy；　a

bridge　of　such　dimensions　was　doubtless　a　bold　as　well　as　an　original

undertaking；　and　the　efficiency　of　the　details　is　worthy　of　the

boldness　of　the　conception。〃*

　＇footnote。。。

Encyclopaedia　Britannica；　8th　ed。　Art。　　〃Iron　Bridges。〃

　。。。＇

Mr。　Stephenson　adds　that　from　a　defect　in　the　construction　the

abutments　were　thrust　inwards　at　the　approaches　and　the　ribs

partially　fractured。　　We　are；　however；　informed　that　this　is　a

mistake；　though　it　does　appear　that　the　apprehension　at　one　time

existed　that　such　an　accident　might　possibly　occur。



To　remedy　the　supposed　defect；　two　small　land　arches　were；　in　the

year　1800；　substituted　for　the　stone　approach　on　the　Broseley　side　of

the　bridge。　　While　the　work　was　in　progress；　Mr。　Telford；　the

well…known　engineer；　carefully　examined　the　bridge；　and　thus　spoke　of

its　condition　at　the　time：　　　〃The　great　improvement　of　erecting　upon

a　navigable　river　a　bridge　of　cast…iron　of　one　arch　only　was　first

put　in　practice　near　Coalbrookdale。　　The　bridge　was　executed　in　1777

by　Mr。　Abraham　Darby；　and　the　ironwork　is　now　quite　as　perfect　as

when　it　was　first　put　up。　　Drawings　of　this　bridge　have　long　been

before　the　public；　and　have　been　much　and　justly　admired。〃*

　＇footnote。。。

PLYMLEY；　General　View　of　the　Agriculture　of　Shropshire。

　。。。＇

A　Coalbrookdale　correspondent；　writing　in　May；　1862；　informs　us　that

〃at　the　present　time　the　bridge　is　undergoing　repair；　and；　special

examination　having　been　made；　there　is　no　appearance　either　that　the

abutments　have　moved；　or　that　the　ribs　have　been　broken　in　the　centre

or　are　out　of　their　proper　right　line。　　There　has；　it　is　true；　been　a

strain　on　the　land　arches；　and　on　the　roadway　plates；　which；　however；

the　main　arch　has　been　able　effectually　to　resist。〃



The　bridge　has　now　been　in　profitable　daily　use　for　upwards　of　eighty

years；　and　has　during　that　time　proved　of　the　greatest　convenience　to

the　population　of　the　district。　　So　judicious　was　the　selection　of　its

site；　and　so　great　its　utility；　that　a　thriving　town　of　the　name　of

Ironbridge　has　grown　up　around　it　upon　what；　at　the　time　of　its

erection；　was　a　nameless　part　of　〃the　waste　of　the　manor　of　Madeley。〃

And　it　is　probable　that　the　bridge　will　last　for　centuries　to　come。

Thus；　also；　was　the　use　of　iron　as　an　important　material　in

bridge…building　fairly　initiated　at　Coalbrookdale　by　Abraham　Darby；

as　the　use　of　iron　rails　was　by　Richard　Reynolds。　　We　need　scarcely

add　that　since　the　invention　and　extensive　adoption　of　railway

locomotion；　the　employment　of　iron　in　various　forms　in　railway　and

bridge　structures　has　rapidly　increased；　until　iron　has　come　to　be

regarded　as　the　very　sheet…anchor　of　the　railway　engineer。



In　the　mean　time　the　works　at　Coalbrookdale　had　become　largely

extended。　　In　1784；　when　the　government　of　the　day　proposed　to　levy　a

tax　on　pit…coal；　Richard　Reynolds　strongly　urged　upon　Mr。　Pitt；　then

Chancellor　of　the　Exchequer；　as　well　as　on　Lord　Gower；　afterwards

Marquis　of　Stafford；　the　impolicy　of　such　a　tax。　　To　the　latter　he

represented　that　large　capitals　had　been　invested　in　the　iron　trade；

which　was　with　difficulty　carried　on　in　the　face　of　the　competition

with　Swedish　and　Russian　iron。　　At　Coalbrookdale；　sixteen　〃fire

engines；〃　as　steam　engines　were　first　called；　were　then　at　work；

eight　blast…furnaces　and　nine　forges；　besides　the　air　furnaces　and

mills　at　the　foundry；　which；　with　the　levels；　roads；　and　more　than

twenty　miles　of　iron　railways；　gave　employment　to　a　very　large　number

of　people。　　〃The　advancement　of　the　iron　trade　within　these　few

years；〃　said　he；　〃has　been　prodigious。　　It　was　thought；　and　justly；

that　the　making　of　pig…iron　with　pit　coal　was　a　great　acquisition　to

the　country　by　saving　the　wood　and　supplying　a　material　to

manufactures；　the　production　of　which；　by　the　consumption　of　all　the

wood　the　country　produced；　was　formerly　unequal　to　the　demand；　and

the　nail　trade；　perhaps　the　most　considerable　of　any　one　article　of

manufactured　iron；　would　have　been　lost　to　this　country　had　it　not

been　found　practicable　to　make　nails　of　iron　made　with　pit　coal。　　We

have　now　another　process　to　attempt；　and　that　is　to　make　BAR　IRON

with　pit　coal；　and　it　is　for　that　purpose　we　have　made；　or　rather　are

making；　alterations　at　Donnington　Wood；　　Ketley；　and　elsewhere；　which

we　expect　to　complete　in　the　present　year；　but　not　at　a　less　expense

than　twenty　thousand　pounds；　which　will　be　lost　to　us；　and　gained　by

nobody；　if　this　tax　is　laid　upon　our　coals。〃　　He　would　not；　however；

have　it　understood　that　he　sought　for　any　PROTECTION　for　the　homemade

iron；　notwithstanding　the　lower　prices　of　the　foreign　article。　　〃From

its　most　imperfect　state　as　pig…iron；〃　he　observed　to　Lord　Sheffield；

〃to　its　highest　finish　in　the　regulating　springs　of　a　watch；　we　have

nothing　to　fear　if　the　importation　into　each　country　should　be

permitted　without　duty。〃　　We　need　scarcely　add　that　the　subsequent

history　of　the　iron　trade　abundantly　justified　these　sagacious

anticipations　of　Richard　Reynolds。



He　was　now　far　advanced　in　years。　　His　business　had　prospered；　his

means　were　ample；　and　he　sought　retirement。　　He　did　not　desire　to

possess　great　wealth；　which　in　his　opinion　entailed　such　serious

responsibilities　upon　its　possessor；　and　he　held　that　the

accumulation　of　large　property　was　more　to　be　deprecated　than

desired。　　He　therefore　determined　to　give　up　his　shares　in　the

ironworks　at　Ketley　to　his　sons　William　and　Joseph；　who　continued　to

carry　them　on。　　William　was　a　man　of　eminent　ability；　well　versed　in

science；　and　an　excellent　mechanic。　　He　introduced　great　improvements

in　the　working　of　the　coal　and　iron　mines；　employing　n