an autobiography-第21部分

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e　Douglas　mortally；　and　to　get　rid　of　the　body　the　king　cast　it　out　of　the　window　of　the　chapel；　where　it　fell　down　the　precipitous　rock　underneath。　　The　chapel　has　since　been　destroyed　by　fire。　　。。。＇　were　the　first　specimens　of　Gothic　carving　in　oak　that　I　had　ever　seen；　and　they　seemed　to　put　our　modern　carvings　to　shame。　　The　Great　Hall；　where　the　Scottish　Parliament　used　to　meet；　was　also　very　interesting　as　connected　with　the　ancient　history　of　the　country。

From　Stirling　we　walked　to　Alloa；　passing　the　picturesque　cascades　rushing　down　the　cleft's　of　the　Ochils。　　We　put　up　for　the　night　at　Clackmannan；　a　very　decayed　and　melancholy…looking　village；　though　it　possessed　a　fine　specimen　of　the　Scottish　castellated　tower。　　It　is　said　that　Robert　Bruce　slept　here　before　the　Battle　of　Bannockburn。　But　the　most　interesting　thing　that　I　saw　during　the　journey　was　the　Devon　Ironworks。　　I　had　read　and　heard　about　the　processes　carried　on　there　in　smelting　iron　ore　and　running　it　into　pig…iron。　　The　origin　of　the　familiar　trade　term　〃pig…iron〃　is　derived　from　the　result　of　the　arrangement　most　suitable　for　distributing　the　molten　iron　as　it　rushes　forth　from　the　opening　made　at　the　bottom　part　of　the　blast…furnace；　when；　after　its　reduction　from　the　ore；　it　collects　in　a　fluid　mass　of　several　tons　weight。　　Previous　to　〃tapping〃　the　furnace　a　great　central　channel　is　made　in　the　sand…covered　floor　of　the　forge；　this　central　channel　is　then　subdivided　into　many　lateral　branches　or　canals；　into　which　the　molten　iron　flows；　and　eventually　hardens。

The　great　steam…engine　that　worked　the　blast　furnace　was　the　largest　I　had　ever　seen。　　A　singular　expedient　was　employed　at　these　works；　of　using　a　vast　vault　hewn　in　the　solid　rock　of　the　hillside　for　the　purpose　of　storing　up　the　blast　produced　by　the　engines；　and　so　equalising　the　pressure；　thus　turning　a　mountain　side　into　a　reservoir　for　the　use　of　a　blast…furnace。　　This　seemed　to　me　a　daring　and　wonderful　engineering　feat。

We　waited　at　the　works　until　the　usual　time　had　arrived　for　letting　out　the　molten　iron　which　had　been　accumulating　at　the　lower　part　of　the　blast…furnace。　　It　was　a　fine　sight　to　see　the　stream　of　white…hot　iron　flowing　like　water　into　the　large　gutter　immediately　before　the　opening。　　From　this　the　molten　iron　flowed　on　until　it　filled　the　moulds　of　sand　which　branched　off　from　the　central　gutter。　　The　iron　left　in　the　centre；　when　cooled　and　broken　up；　was　called　sow　metal；　while　that　in　the　branches　was　called　pig　iron；　the　terms　being　derived　from　the　appearance　of　a　sow　engaged　in　its　maternal　duties。　The　pig…iron　is　thus　cast　in　handy…sized　pieces　for　the　purpose　of　being　transported　to　other　iron　foundries；　while　the　clumsy　sow　metal　is　broken　up　and　passes　through　another　process　of　melting；　or　is　reserved　for　foundry　uses　at　the　works　where　it　is　produced。　After　inspecting　with　great　pleasure　the　machinery　connected　with　the　foundry；　we　took　our　leave　and　returned　to　Edinburgh　by　steamer　from　Alloa。

Shortly　after；　I　had　the　good　fortune　to　make　the　acquaintance　of　Robert　Bald；　the　well…known　mining　engineer。　　He　was　one　of　the　most　kind…hearted　men　I　have　ever　known。　　He　was　always　ready　to　communicate　his　knowledge　to　young　and　old。　　His　sound　judgment　and　long　practical　experience　in　regard　to　coal…mining　and　the　various　machinery　connected　with　it；　rendered　him　a　man　of　great　importance　in　the　northern　counties；　where　his　advice　was　eagerly　sought　for。　Besides　his　special　knowledge；　he　had　a　large　acquaintance　with　literature　and　science。　He　was　bright；　lively；　and　energetic。　　He　was　a　living　record　of　good　stories；　and　in　every　circle　in　which　he　moved　he　was　the　focus　of　cheerfulness。　　In　fact；　there　was　no　greater　social　favourite　in　Edinburgh　than　Robert　Bald。

Bald　was　very　fond　of　young　people；　and　he　became　much　attached　to　me。　He　used　to　come　to　my　father's　house；　and　often　came　in　to　see　what　I　was　about　in　the　work…room。　　He　was　rejoiced　to　see　the　earnest　and　industrious　manner　in　which　I　was　employed；　in　preparing　myself　for　my　proposed　business　as　an　engineer。　　He　looked　over　my　tools；　mostly　of　my　own　making；　and　gave　me　every　encouragement。　　When　he　had　any　visitors　he　usually　brought　them　and　introduced　them　to　me。　　In　this　way　I　had　the　happiness　to　make　the　acquaintance　of　Robert　Napier；　Nelson；　and　Cook；　of　Glasgow；　and　in　after　life　I　continued　to　enjoy　their　friendship。　　It　would　be　difficult　for　me　to　detail　the　acts　of　true　disinterested　kindness　which　I　continued　to　receive　from　this　admirable　man。

On　several　occasions　he　wished　me　to　accompany　him　on　his　business　journeys；　in　order　that　I　might　see　some　works　that　would　supply　me　with　valuable　information。　　He　had　designed　a　powerful　pumping　engine　to　drain　more　effectually　a　large　colliery　district　situated　near　Bannockburnclose　to　the　site　of　the　great　battle　in　the　time　of　Robert　the　Bruce。　　He　invited　me　to　join　him。　　It　was　with　the　greatest　pleasure　that　I　accepted　his　invitation；　for　there　would　be　not　only　the　pleasure　of　seeing　a　noble　piece　of　steam　machinery　brought　into　action　for　the　first　time；　but　also　the　enjoyment　of　visiting　the　celebrated　Carron　Ironworks。

The　Carron　Ironworks　are　classic　ground　to　engineers。　　They　are　associated　with　the　memory　of　Roebuck；　Watt；　and　Miller　of　Dalswinton。　For　there　Roebuck　and　Watt　began　the　first　working　steam…engine；　Miller　applied　the　steam…engine　to　the　purposes　of　navigation；　and　invented　the　Carronade　gun。　　The　works　existed　at　an　early　period　in　the　history　of　British　iron　manufacture。　　Much　of　the　machinery　continued　to　be　of　wood。　　Although　effective　in　a　general　way　it　was　monstrously　cumbrous。　It　gave　the　idea　of　vast　power　and　capability　of　resistance；　while　it　was　far　from　being　so　in　reality。　It　was；　however；　truly　imposing　and　impressive　in　its　effect　upon　strangers。　　When　seen　partially　lit　up　by　the　glowing　masses　of　white…hot　iron；　with　only　the　rays　of　bright　sunshine　gleaming　through　a　few　holes　in　the　roof；　and　the　dark；　black；　smoky　vaults　in　which　the　cumbrous　machinery　was　heard　rumbling　away　in　the　distancewhile　the　moving　parts　were　dimly　seen　through　the　murky　atmosphere；　mixed　with　the　sounds　of　escaping　steam　and　rushes　of　water；　with　the　half…naked　men　darting　about　with　masses　of　red…hot　iron　and　ladles　full　of　molten　cast…ironit　made　a　powerful　impression　upon　the　mind。

I　was　afterwards　greatly　interested　by　a　collection　of　old　armour；　dug　up　from　the　field　of　the　Battle　of　Bannockburn　close　at　hand。　They　were　arranged　on　the　walls　of　the　house　of　the　manager　of　the　Carron　Ironworks。　　There　were　swords；　daggers；　lances；　battle…axes；　shields；　and　coats　of　chain…armour。　　Some　of　the　latter　were　whole；　others　in　fragmentary　portions。　　I　was　particularly　interested　with　the　admirable　workmanship　of　the　coats　of　mail。　　The　iron　links　extended　from　the　covering　of　the　head　to　the　end　of　the　arms；　and　from　the　shoulders　down　to　the　hips；　in　one　linked　iron　fabric。　　The　beauty　and　exactness　with　which　this　chain…armour　had　been　forged　and　built　up　were　truly　wonderful。　　There　must　have　been　〃giants　in　those　days。〃　　This　grand　style　of　armour　was　in　use　from　the　time　of　the　Conquest；　and　was　most　effective　in　the　way　of　protection；　as　it　was　fitted　by　its　flexibility　to　give　full　play　to　the　energetic　action　of　the　wearer。　　It　was　infinitely　superior　to　the　senseless　plate…armour　that　was　used；　at　a　subsequent　period；　to　encase　soldiers　like　lobsters。　　The　chain…armour　I　saw　at　Carron　left　a　deep　impression　on　my　mind。　　I　never　see　a　bit　of　it；　or　of　its　representation　in　the　figures　on　our　grand　tombs　of　the　thirteenth　century；　but　I　think　of　my　first　sight　of　it　at　Carron　and　of　the　tremendous　conflict　at　Bannockburn。

Remembering；　also；　the　impressive　sight　of　the　picturesque　fire…lit　halls；　and　the　terrible…looking；　cumbrous　machinery　which　I　first　beheld　on　a　grand　scale　at　Carron；　I　have　often　regretted　that　some　of　our　artists　do　not　follow　up　the　example　set　them　by　that　admirable　painter；　Wright　of　Derby；　and　treat　us　to　the　pictures　of　some　of　our　great　ironworks。　　They　not　only　abound　with　the　elements　of　the　picturesque　in　its　highest　sense；　but　also　set　forth　the　glory　of　the　useful　arts　in　such　a　way　as　would　worthily　call　forth　the　highest　power　of　our　artists。

To　return　to　my　life　at　Edinburgh。　　I　was　now　seventeen　years　old。　I　had　acquired　a　considerable　amount　of　practical　knowledge　as　to　the　use　and　handling　of　mechanical　tools；　and　I　desired　to　turn　it　to　some　account。　　I　was　able　to　construct　working　models　of　steam…engines　and　other　apparatus　required　for　the　illustration　of　mechanical　subjects。　I　began　with　making　a　small　working　steam　engine　for　the　purpose　of　grinding　the　oil…colours　used　by　my　father　in　his　artistic　work。　The　result　was　quite　satisfactory。　　Many　persons　came　to　see　my　active　little　steam…engine　at　work；　and　they　were　so　pleased　with　it　that　I　received　several　orders　for　small　workshop　engines；　and　also　for　some　models　of　steam…engines　to　illustrate　the　subjects　taught　at　Mechanics'　Institutions。

＇Image＇　　Sectional　model　of　condensing　steam…engine。　　By　James　Nasmyth

I　contrived　a　sectional　model　of　a　complete　condensing　steam…engine　of　the　beam　and　parallel　motion　construction。　　The　model；　as　seen　from　one　side；　exhibited　every　external　detail　in　full　and　due　action　when　the　flywheel　was　moved　round　by　hand；　while；　on　the　other　or　sectional　side；　every　detail　of　the　interior　was　seen；　with　the　steam…valves　and　air…pump；　as　well　as　the　motion　of　the　piston　in　the　cylinder；　with　the　construction　of　the　piston　and　the　stuffing　box；　together　with　the　slide…valve　and　steam　passages；　all　in　due　position　and　relative　movement。

The　first　of　these　sectional　models　of　the　steam…engine　was　made　for　the　Edinburgh　School　of　Arts；　where　its　uses　in　instructing　mechanics　and　others　in　the　application　of　steam　were　highly　appreciated。　The　second　was　made　for　Professor　Leslie；　of　the　Edinburgh　University；　for　use　in　his　lectures　on　Natural　Philosophy。　　The　professor　had；　at　his　own　private　cost；　provided　a　complete　and　excellent　set　of　apparatus；　which；　for　excellent　workmanship　and　admirable　utility；　had　never；　I　believe；　been　provided　for　the　service　of　any　uni