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Footnotes¡¡for¡¡Chapter¡¡VI¡£
*£§1£§¡¡The¡¡Ellesmere¡¡Canal¡¡now¡¡pays¡¡about¡¡4¡¡per¡¡cent¡£¡¡dividend¡£
*£§2£§¡¡'A¡¡General¡¡History¡¡of¡¡Inland¡¡Navigation£»¡¡Foreign¡¡and
Domestic£»'¡¡&c¡£¡¡By¡¡J¡£¡¡Phillips¡£¡¡¡¡Fourth¡¡edition¡£¡¡¡¡London£»¡¡1803¡£
*£§3£§¡¡£§Image£§¡¡Section¡¡of¡¡Pier
Telford¡¡himself¡¡thus¡¡modestly¡¡describes¡¡the¡¡merit¡¡of¡¡this¡¡original
contrivance£º¡¡¡¨Previously¡¡to¡¡this¡¡time¡¡such¡¡canal¡¡aqueducts¡¡had¡¡been
uniformly¡¡made¡¡to¡¡retain¡¡the¡¡water¡¡necessary¡¡for¡¡navigation¡¡by
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occurred¡¡even¡¡in¡¡the¡¡works¡¡of¡¡the¡¡justly¡¡celebrated¡¡Brindley¡£
It¡¡was¡¡evident¡¡that¡¡the¡¡increased¡¡pressure¡¡of¡¡the¡¡puddled¡¡earth¡¡was
the¡¡chief¡¡cause¡¡of¡¡such¡¡failures£º¡¡I¡¡therefore¡¡had¡¡recourse¡¡to¡¡the
following¡¡scheme¡¡in¡¡order¡¡to¡¡a¡¡void¡¡using¡¡it¡£¡¡¡¡The¡¡spandrels¡¡of¡¡the
stone¡¡arches¡¡were¡¡constructed¡¡with¡¡longitudinal¡¡walls£»¡¡instead¡¡of
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these¡¡the¡¡canal¡¡bottom¡¡was¡¡formed¡¡by¡¡cast¡¡iron¡¡plates¡¡at¡¡each¡¡side£»
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masonry£»¡¡backed¡¡with¡¡hard¡¡burnt¡¡bricks¡¡laid¡¡in¡¡Parker's¡¡cement£»¡¡on
the¡¡outside¡¡of¡¡which¡¡was¡¡rubble¡¡stone¡¡work£»¡¡like¡¡the¡¡rest¡¡of¡¡the
aqueduct¡£¡¡¡¡The¡¡towing¡¡path¡¡had¡¡a¡¡thin¡¡bed¡¡of¡¡clay¡¡under¡¡the¡¡gravel£»
and¡¡its¡¡outer¡¡edge¡¡was¡¡protected¡¡by¡¡an¡¡iron¡¡railing¡£¡¡¡¡The¡¡width¡¡of
the¡¡water¡way¡¡is¡¡11¡¡feet£»¡¡of¡¡the¡¡masonry¡¡on¡¡each¡¡side£»¡¡5¡¡feet¡¡6
inches£»¡¡and¡¡the¡¡depth¡¡of¡¡the¡¡water¡¡in¡¡the¡¡canal£»¡¡5¡¡feet¡£¡¡¡¡By¡¡this
mode¡¡of¡¡construction¡¡the¡¡quantity¡¡of¡¡masonry¡¡is¡¡much¡¡diminished£»
and¡¡the¡¡iron¡¡bottom¡¡plate¡¡forms¡¡a¡¡continuous¡¡tie£»¡¡preventing¡¡the
side¡walls¡¡from¡¡separation¡¡by¡¡lateral¡¡pressure¡¡of¡¡the¡¡contained
water¡£¡¨'Life¡¡of¡¡Telford£»'¡¡p¡£¡¡40¡£
*£§4£§¡¡Letter¡¡to¡¡Mr¡£¡¡Andrew¡¡Little£»¡¡Langholm£»¡¡dated¡¡Shrewsbury£»
13th¡¡March£»¡¡1795¡£
*£§5£§¡¡Matthew¡¡Davidson¡¡had¡¡been¡¡Telford's¡¡fellow¡¡workman¡¡at¡¡Langholm£»
and¡¡was¡¡reckoned¡¡an¡¡excellent¡¡mason¡£¡¡¡¡He¡¡died¡¡at¡¡Inverness£»
where¡¡he¡¡had¡¡a¡¡situation¡¡on¡¡the¡¡Caledonian¡¡Canal¡£
*£§6£§¡¡Mr¡£¡¡Hughes£»¡¡C¡£E¡££»¡¡in¡¡his¡¡'Memoir¡¡of¡¡William¡¡Jessop£»'¡¡published
in¡¡'Weale's¡¡Quarterly¡¡Papers¡¡on¡¡Engineering£»'¡¡points¡¡out¡¡the¡¡bold
and¡¡original¡¡idea¡¡here¡¡adopted£»¡¡of¡¡constructing¡¡a¡¡water¡tight
trough¡¡of¡¡cast¡¡iron£»¡¡in¡¡which¡¡the¡¡water¡¡of¡¡the¡¡canal¡¡was¡¡to¡¡be
carried¡¡over¡¡the¡¡valleys£»¡¡instead¡¡of¡¡an¡¡immense¡¡puddled¡¡trough£»
in¡¡accordance¡¡with¡¡the¡¡practice¡¡until¡¡that¡¡time¡¡in¡¡use£»¡¡and¡¡he¡¡adds£»
¡¨the¡¡immense¡¡importance¡¡of¡¡this¡¡improvement¡¡on¡¡the¡¡old¡¡practice¡¡is
apt¡¡to¡¡be¡¡lost¡¡sight¡¡of¡¡at¡¡the¡¡present¡¡day¡¡by¡¡those¡¡who¡¡overlook
the¡¡enormous¡¡size¡¡and¡¡strength¡¡of¡¡masonry¡¡which¡¡would¡¡have¡¡been
required¡¡to¡¡support¡¡a¡¡puddled¡¡channel¡¡at¡¡the¡¡height¡¡of¡¡120¡¡feet¡£¡¨
Mr¡£¡¡Hughes£»¡¡however£»¡¡claims¡¡for¡¡Mr¡£¡¡Jessop¡¡the¡¡merit¡¡of¡¡having
suggested¡¡the¡¡employment¡¡of¡¡iron£»¡¡though£»¡¡in¡¡our¡¡opinion£»¡¡without
sufficient¡¡reason¡£
Mr¡£¡¡Jessop¡¡was£»¡¡no¡¡doubt£»¡¡consulted¡¡by¡¡Mr¡£¡¡Telford¡¡on¡¡the¡¡subject£»
but¡¡the¡¡whole¡¡details¡¡of¡¡the¡¡design£»¡¡as¡¡well¡¡as¡¡the¡¡suggestion¡¡of
the¡¡use¡¡of¡¡iron¡¡£¨as¡¡admitted¡¡by¡¡Mr¡£¡¡Hughes¡¡himself£©£»¡¡and¡¡the
execution¡¡of¡¡the¡¡entire¡¡works£»¡¡rested¡¡with¡¡the¡¡acting¡¡engineer¡£
This¡¡is¡¡borne¡¡out¡¡by¡¡the¡¡report¡¡published¡¡by¡¡the¡¡Company
immediately¡¡after¡¡the¡¡formal¡¡opening¡¡of¡¡the¡¡Canal¡¡in¡¡1805£»¡¡in¡¡which
they¡¡state£º¡¡¡¨Having¡¡now¡¡detailed¡¡the¡¡particulars¡¡relative¡¡to¡¡the
Canal£»¡¡and¡¡the¡¡circumstances¡¡of¡¡the¡¡concern£»¡¡the¡¡committee£»¡¡in
concluding¡¡their¡¡report£»¡¡think¡¡it¡¡but¡¡justice¡¡due¡¡to¡¡Mr¡£¡¡Telford¡¡to
state¡¡that¡¡the¡¡works¡¡have¡¡been¡¡planned¡¡with¡¡great¡¡skill¡¡and
science£»¡¡and¡¡executed¡¡with¡¡much¡¡economy¡¡and¡¡stability£»¡¡doing¡¡him£»
as¡¡well¡¡as¡¡those¡¡employed¡¡by¡¡him£»¡¡infinite¡¡credit¡£¡¡¡¡£¨Signed£©
Bridgewater¡£¡¨
*£§7£§¡¡Letter¡¡to¡¡Mr¡£¡¡Andrew¡¡Little£»¡¡Langholm£»¡¡dated¡¡Shrewsbury£»
16th¡¡Sept¡££»¡¡1794¡£
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*£§9£§¡¡Letter¡¡to¡¡Mr¡£¡¡Andrew¡¡Little£»¡¡Langholm£»¡¡dated¡¡Salop£»¡¡20th¡¡Aug¡££»
1797¡£
CHAPTER¡¡VII¡£
IRON¡¡AND¡¡AND¡¡OTHER¡¡BRIDGES¡£
Shrewsbury¡¡being¡¡situated¡¡in¡¡the¡¡immediate¡¡neighbourhood¡¡of¡¡the
Black¡¡Country£»¡¡of¡¡which¡¡coal¡¡and¡¡iron¡¡are¡¡the¡¡principal¡¡products£»
Telford's¡¡attention¡¡was¡¡naturally¡¡directed£»¡¡at¡¡a¡¡very¡¡early¡¡period£»
to¡¡the¡¡employment¡¡of¡¡cast¡¡iron¡¡in¡¡bridge¡building¡£¡¡¡¡The¡¡strength¡¡as
well¡¡as¡¡lightness¡¡of¡¡a¡¡bridge¡¡of¡¡this¡¡material£»¡¡compared¡¡with¡¡one
of¡¡stone¡¡and¡¡lime£»¡¡is¡¡of¡¡great¡¡moment¡¡where¡¡headway¡¡is¡¡ofimportance£»
or¡¡the¡¡difficulties¡¡of¡¡defective¡¡foundations¡¡have¡¡to¡¡be¡¡encountered¡£
The¡¡metal¡¡can¡¡be¡¡moulded¡¡in¡¡such¡¡precise¡¡forms¡¡and¡¡so¡¡accurately
fitted¡¡together¡¡as¡¡to¡¡give¡¡to¡¡the¡¡arching¡¡the¡¡greatest¡¡possible
rigidity£»¡¡while¡¡it¡¡defies¡¡the¡¡destructive¡¡influences¡¡of¡¡time¡¡and
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to¡¡the¡¡end¡¡of¡¡last¡¡century£»¡¡early¡¡detected¡¡the¡¡value¡¡of¡¡this¡¡material£»
and¡¡made¡¡several¡¡attempts¡¡to¡¡introduce¡¡it¡¡in¡¡bridge¡building£»
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inability¡¡of¡¡the¡¡early¡¡founders¡¡to¡¡cast¡¡large¡¡masses¡¡of¡¡iron£»
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made¡¡at¡¡Lyons¡¡in¡¡1755£»¡¡and¡¡it¡¡proceeded¡¡so¡¡far¡¡that¡¡one¡¡of¡¡the
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difficulties¡¡which¡¡had¡¡baffled¡¡the¡¡foreign¡¡iron¡founders¡£¡¡¡¡Shortly
after¡¡the¡¡above¡¡ineffectual¡¡attempt¡¡had¡¡been¡¡made£»¡¡the¡¡construction
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