the life of thomas telford- 第47部分

Commissioners；　they　were　enabled　to　proceed　with　the　completion　of

their　undertaking。　A　capacious　canal　was　cut　from　Gloucester　to

Sharpness　Point；　about　eight　miles　down　the　Severn；　which　had　the

effect　of　greatly　improving　the　convenience　of　the　port　of

Gloucester；　and　by　means　of　this　navigation；　ships　of　large　burden

can　now　avoid　the　circuitous　and　difficult　passage　of　the　higher

part　of　the　river；　very　much　to　the　advantage　of　the　trade　of　the

place。



The　formation　of　a　new　tunnel　through　Harecastle　Hill；　for　the

better　accommodation　of　the　boats　passing　along　the　Grand　Trunk

Canal；　was　a　formidable　work。　　The　original　tunnel；　it　will　be

remembered；*＇3＇　was　laid　out　by　Brindley；　about　fifty　years

before；　and　occupied　eleven　years　in　construction。　　But　the

engineering　appliances　of　those　early　days　were　very　limited；　the

pumping　powers　of　the　steam…engine　had　not　been　fairly　developed；

and　workmen　were　as　yet　only　half…educated　in　the　expert　use　of

tools。　　The　tunnel；　no　doubt；　answered　the　purpose　for　which　it　was

originally　intended；　but　it　was　very　soon　found　too　limited　for　the

traffic　passing　along　the　navigation。　　It　was　little　larger　than　a

sewer；　and　admitted　the　passage　of　only　one　narrow　boat；　seven　feet

wide；　at　a　time；　involving　very　heavy　labour　on　the　part　of　the　men

who　worked　it　through。　　This　was　performed　by　what　was　called

legging。　　The　Leggers　lay　upon　the　deck　of　the　vessel；　or　upon　a

board　slightly　projecting　from　either　side　of　it；　and；　by　thrusting

their　feet　against　the　slimy　roof　or　sides　of　the　tunnel…walking

horizontally　as　it　were　　they　contrived　to　push　it　through。

But　it　was　no　better　than　horsework；　and　after　〃legging〃　Harecastle

Tunnel；　which　is　more　than　a　mile　and　a　half　long；　the　men　were

usually　completely　exhausted；　and　as　wet　from　perspiration　as　if

they　had　been　dragged　through　the　canal　itself。　　The　process

occupied　about　two　hours；　and　by　the　time　the　passage　of　the　tunnel

was　made；　there　was　usually　a　collection　of　boats　at　the　other　end

waiting　their　turn　to　pass。　　Thus　much　contention　and　confusion

took　place　amongst　the　boatmena　very　rough　class　of　labourers

and　many　furious　battles　were　fought　by　the　claimants　for　the　first

turn　〃through。〃　　Regulations　were　found　of　no　avail　to　settle　these

disputes；　still　less　to　accommodate　the　large　traffic　which

continued　to　keep　flowing　along　the　line　of　the　Grand　Trunk；

and　steadily　increased　with　the　advancing　trade　and　manufactures　of

the　country。　　Loud　complaints　were　made　by　the　public；　but　they　were

disregarded　for　many　years；　and　it　was　not　until　the　proprietors

were　threatened　with　rival　canals　and　railroads　that　they

determined　onwhat　they　could　no　longer　avoid　if　they　desired　to

retain　the　carrying　trade　of　the　district　the　enlargement　of　the

Harecastle　Tunnel。



Mr。　Telford　was　requested　to　advise　the　Company　what　course　was

most　proper　to　be　adopted　in　the　matter；　and　after　examining　the

place；　he　recommended　that　an　entirely　new　tunnel　should　be

constructed；　nearly　parallel　with　the　old　one；　but　of　much　larger

dimensions。　The　work　was　begun　in　1824；　and　completed　in　1827；

in　less　than　three　years。　　There　were　at　that　time　throughout　the

country　plenty　of　skilled　labourers　and　contractors；　many　of　them

trained　by　their　experience　upon　Telford's　own　works；　where　as

Brindley　had　in　a　great　measure　to　make　his　workmen　out　of　the

rawest　material。　Telford　also　had　the　advantage　of　greatly　improved

machinery　and　an　abundant　supply　of　moneythe　Grand　Trunk　Canal

Company　having　become　prosperous　and　rich；　paying　large　dividends。

It　is　therefore　meet；　while　eulogising　the　despatch　with　which　he

was　enabled　to　carry　out　the　work；　to　point　out　that　the　much

greater　period　occupied　in　the　earlier　undertaking　is　not　to　be　set

down　to　the　disparagement　of　Brindley；　who　had　difficulties　to

encounter　which　the　later　engineer　knew　nothing　of。



The　length　of　the　new　tunnel　is　2926　yards；　it　is　16　feet　high　and

14　feet　broad；　4　feet　9　inches　of　the　breadth　being　occupied　by　the

towing…pathfor　〃legging〃　was　now　dispensed　with；　and　horses

hauled　along　the　boats　instead　of　their　being　thrust　through　by

men。　The　tunnel　is　in　so　perfectly　straight　a　line　that　its　whole

length　can　be　seen　through　at　one　view；　and　though　it　was

constructed　by　means　of　fifteen　different　pitshafts　sunk　to　the

same　line　along　the　length　of　the　tunnel；　the　workmanship　is　so

perfect　that　the　joinings　of　the　various　lengths　of　brickwork　are

scarcely　discernible。　　The　convenience　afforded　by　the　new　tunnel

was　very　great；　and　Telford　mentions　that；　on　surveying　it　in　1829；

he　asked　a　boatman　coming；　out　of　it　how　he　liked　it？　　〃I　only

wish；〃　he　replied；　〃that　it　reached　all　the　way　to　Manchester！〃



＇Image＇　Cross　Section　of　Harecastle　Tunnel。



At　the　time　that　Mr。　Telford　was　engaged　upon　the　tunnel　at

Harecastle；　he　was　employed　to　improve　and　widen　the　Birmingham

Canal；　another　of　Brindley's　works。　　Though　the　accommodation

provided　by　it　had　been　sufficient　for　the　traffic　when　originally

constructed；　the　expansion　of　the　trade　of　Birmingham　and　the

neighbourhood；　accelerated　by　the　formation　of　the　canal　itself；

had　been　such　as　completely　to　outgrow　its　limited　convenience　and

capacity；　and　its　enlargement　and　improvement　now　became　absolutely

necessary。　　Brindley's　Canal；　for　the　sake　of　cheapness　of

constructionmoney　being　much　scarcer　and　more　difficult　to　be

raised　in　the　early　days　of　canalswas　also　winding　and　crooked；

and　it　was　considered　desirable　to　shorten　and　straighten　it　by

cutting　off　the　bends　at　different　places。　　　At　the　point　at　which

the　canal　entered　Birmingham；　it　had　become　〃little　better　than　a

crooked　ditch；　with　scarcely　the　appearance　of　a　towing…path；　the

horses　frequently　sliding　and　staggering　in　the　water；　the

hauling…lines　sweeping　the　gravel　into　the　canal；　and　the

entanglement　at　the　meeting　of　boats　being　incessant；　whilst　at　the

locks　at　each　end　of　the　short　summit　at　Smethwick　crowds　of

boatmen　were　always　quarrelling；　or　offering　premiums　for　a

preference　of　passage；　and　the　mine…owners；　injured　by　the　delay；

were　loud　in　their　just　complaints。〃*＇4＇



Mr。　Telford　proposed　an　effective　measure　of　improvement；　which

was　taken　in　hand　without　loss　of　time；　and　carried　out；　greatly

to　the　advantage　of　the　trade　of　the　district。　　The　numerous　bends

in　the　canal　were　cut　off；　the　water…way　was　greatly　widened；　the

summit　at　Smethwick　was　cut　down　to　the　level　on　either　side；　and　a

straight　canal；　forty　feet　wide；　without　a　lock；　was　thus　formed

as　far　as　Bilston　and　Wolverhampton；　while　the　length　of　the　main

line　between　Birmingham　and　Autherley；　along　the　whole　extent　of

the　〃Black　country；〃　was　reduced　from　twenty…two　to　fourteen　miles。

At　the　same　time　the　obsolete　curvatures　in　Brindley's　old　canal

were　converted　into　separate　branches　or　basins；　for　the

accommodation　of　the　numerous　mines　and　manufactories　on　either

side　of　the　main　line。　In　consequence　of　the　alterations　which　had

been　made　in　the　canal；　it　was　found　necessary　to　construct

numerous　large　bridges。　　One　of　thesea　cast　iron　bridge；

at　Galton；　of　150　feet　spanhas　been　much　admired　for　its　elegance；

lightness；　and　economy　of　material。　Several　others　of　cast　iron

were　constructed　at　different　points；　and　at　one　place　the　canal

itself　is　carried　along　on　an　aqueduct　of　the　same　material　as　at

Pont…Cysylltau。　　The　whole　of　these　extensive　improvements　were

carried　out　in　the　short　space　of　two　years；　and　the　result　was

highly　satisfactory；　〃proving；〃　as　Mr。　Telford　himself　observes；

〃that　where　business　is　extensive；　liberal　expenditure　of　this　kind

is　true　economy。〃



＇Image＇　Galton　Bridge；　Birmingham　Canal。



In　1825　Mr。　Telford　was　called　upon　to　lay　out　a　canal　to　connect

the　Grand　Trunk；　at　the　north　end　of　Harecastle　Tunnel；　with　the

rapidly　improving　towns　of　Congleton　and　Macclesfield。　　The　line

was　twenty…nine　miles　in　length；　ten　miles　on　one　level　from

Harecastle　to　beyond　Congleton；　then；　ascending　114　feet　by　eleven

locks；　it　proceeded　for　five　miles　on　a　level　past　Macclesfield；

and　onward　to　join　the　Peak　Forest　Canal　at　Marple。　　The　navigation

was　thus　conducted　upon　two　levels；　each　of　considerable　length；

and　it　so　happened　that　the　trade　of　each　was　in　a　measure

distinct；　and　required　separate　accommodation。　　The　traffic　of　the

whole　of　the　Congleton　district　had　ready　access　to　the　Grand　Trunk

system；　without　the　labour；　expense；　and　delay　involved　by　passing

the　boats　through　locks；　while　the　coals　brought　to　Macclesfield　to

supply　the　mills　there　were　carried　throughout　upon　the　upper

level；　also　without　lockage。　　The　engineer's　arrangement　proved

highly　judicious；　and　furnishes　an　illustration　of　the　tact　and

judgment　which　he　usually　displayed　in　laying　out　his　works　for

practical　uses。　Mr　Telford　largely　employed　cast　iron　in　the

construction　of　this　canal；　using　it　in　the　locks　and　gates；　as

well　as　in　an　extensive　aqueduct　which　it　was　necessary　to

construct　over　a　deep　ravine；　after　the　plan　pursued　by　him　at；

Pont…Cysylltau　and　other　places。



The　last　canal　constructed　by。　　Mr。　Telford　was　the　Birmingham　and

Liverpool　Junction；　extending　from　the　Birmingham　Canal；　near

Wolverhampton；　in　nearly　a　direct　line；　by　Market　Drayton；

Nantwich；　and　through　the　city　of　Chester；　by　the　Ellesmere　Canal；

to　Ellesmere　Port　on　the　Mersey。　　The　proprietors　of　canals　were

becoming　alarmed　at　the　numerous　railways　projected　through　the

districts　heretofore　served　by　their　water…ways；　and　among　other

projects　one　was　set　on　foot；　as　early　as　1825；　for　constructing　a

line　of　railway　from　London　to　Liverpool。　　Mr。　Telford　was

consulted　as　to　the　best　means　of　protecting　existing　investments；

and　his　advice　was　to　render　the　canal　system　as　complete　as　it

could　be　made；　for　he　entertained　the　convi