Manyotherlargefirmsnowcompetefortheirshareofthetrade;andtheextenttowhichithasgrown,thenumberoffurnacesconstantlyatwork,andthequantityofsteelcastintoingots,tobetiltedorrolledforthevariouspurposestowhichitisapplied,haverenderedSheffieldthegreatestlaboratoryintheworldofthisvaluablematerial。Ofthetotalquantityofcast-steelmanufacturedinEngland,notlessthanfive-sixthsareproducedthere;andthefacilitiesforexperimentandadaptationonthespothaveenabledtheSheffieldsteel-makerstokeeptheleadinthemanufacture,andsurpassallothersintheperfectiontowhichtheyhavecarriedthisimportantbranchofournationalindustry。Itisindeedaremarkablefactthatthisverytown,whichwasformerlyindebtedtoStyriaforthesteelusedinitsmanufactures,nowexportsamaterialofitsownconversiontotheAustrianforgesandotherplacesontheContinentfromwhichitwasbeforeaccustomedtodrawitsownsupplies。
AmongtheimprovedprocessesinventedoflateyearsforthemanufactureofsteelarethoseofHeath,Mushet,andBessemer。Thelastpromisestoeffectbeforelonganentirerevolutionintheironandsteeltrade。Byitthecrudemetalisconvertedbyonesimpleprocess,directlyasitcomesfromtheblast-furnace。Thisiseffectedbydrivingthroughit,whilestillinamoltenstate,severalstreamsofatmosphericair,onwhichthecarbonofthecrudeironuniteswiththeoxygenoftheatmosphere,thetemperatureisgreatlyraised,andaviolentebullitiontakesplace,duringwhich,iftheprocessbecontinued,thatpartofthecarbonwhichappearstobemechanicallymixedanddiffusedthroughthecrudeironisentirelyconsumed。Themetalbecomesthoroughlycleansed,theslagisejectedandremoved,whilethesulphurandothervolatilemattersaredrivenoff;theresultbeinganingotofmalleableironofthequalityofcharcoaliron。Animportant。featureintheprocessis,thatbystoppingitataparticularstage,immediatelyfollowingtheboil,beforethewholeofthecarbonhasbeenabstractedbytheoxygen,thecrudeironwillbefoundtohavepassedintotheconditionofcast-steelofordinaryquality。Bycontinuingtheprocess,themetallosingitscarbon,itpassesfromhardtosoftsteel,thencetosteelyiron,andlastofalltoverysoftiron;sothatbyinterruptingtheprocessatanystage,orcontinuingittotheend,almostanyqualityofironandsteelmaybeobtained。OneofthemostvaluableformsofthemetalisdescribedbyMr。Bessemeras”semi-steel,”beinginhardnessaboutmidwaybetweenordinarycast-steelandsoftmalleableiron。TheBessemerprocessesarenowinfulloperationinEnglandaswellasabroad,bothforconvertingcrudeintomalleableiron,andforproducingsteel;andtheresultsareexpectedtoproveofthegreatestpracticalutilityinallcaseswhereironandsteelareextensivelyemployed。
Yet,likeeveryotherinvention,thisofMr。Bessemerhadlongbeendreamtof,ifnotreallymade。WeareinformedinWarner’sTourthroughtheNorthern。CountiesofEngland,publishedatBathinl80L,thataMr。ReedofWhitehavenhadsucceededatthatearlyperiodinmakingsteeldirectfromtheore;andMr。Mushetclearlyalludestotheprocessinhis”PapersonIronandSteel。”Nevertheless,Mr。
Bessemerisentitledtothemeritofworkingouttheidea,andbringingtheprocesstoperfection,byhisgreatskillandindomitableperseverance。IntheHeathprocess,carburetofmanganeseisemployedtoaidtheconversionofironintosteel,whileitalsoconfersonthemetalthepropertyofweldingandworkingmoresoundlyunderthehammer——afactdiscoveredbyMr。HeathwhileresidinginIndia。Mr。Mushet’sprocessisofasimilarcharacter。Anotherinventor,MajorUchatius,anAustrianengineer,granulatescrudeironwhileinamoltenstatebypouringitintowater,andthensubjectingittotheprocessofconversion。Someofthemanufacturersstillaffectsecrecyintheiroperations;butasoneoftheSandersonfirm——famousfortheexcellenceoftheirsteel——remarkedtoavisitorwhenshowinghimovertheirworks,”thegreatsecretistohavethecouragetobehonest——aspirittopurchasethebestmaterial,andthemeansanddispositiontodojusticetoitinthemanufacture。”
Itremainstobeadded,thatmuchofthesuccessoftheSheffieldmanufacturesisattributabletothepracticalskilloftheworkmen,whohaveprofitedbytheaccumulatedexperiencetreasuredupbytheirclassthroughmanygenerations。Theresultsoftheinnumerableexperimentsconductedbeforetheireyeshaveissuedinamostvaluablethoughunwrittencodeofpractice,thedetailsofwhichareknownonlytothemselves。Theyarealsoamostlaboriousclass;andLePlaysaysofthem,whenalludingtothefactofasingleworkmansuperintendingtheoperationsofthreesteel-castingfurnaces——”I
havefoundnowhereinEurope,exceptinEngland,workmenableforanentireday,withoutanyintervalofrest,toundergosuchtoilsomeandexhaustinglabourasthatperformedbytheseSheffieldworkmen。”
CHAPTERVII。
THEINVENTIONSOFHENRYCORT。”Ihavealwaysfounditinmineownexperienceaneasiermattertodevisemanieandprofitableinventions,thantodisposeofoneofthemtothegoodoftheauthorhimself。”——SirHughPlatt,1589。
HenryCortwasbornin1740atLancaster,wherehisfathercarriedonthetradeofabuilderandbrickmaker。NothingisknownastoHenry’searlyhistory;butheseemstohaveraisedhimselfbyhisowneffortstoarespectableposition。In1765wefindhimestablishedinSurreyStreet,Strand,carryingonthebusinessofanavyagent,inwhichheissaidtohaverealizedconsiderableprofits。ItwaswhileconductingthisbusinessthathebecameawareoftheinferiorityofBritishironcomparedwiththatobtainedfromforeigncountries。TheEnglishwroughtironwasconsideredsobadthatitwasprohibitedfromallgovernmentsupplies,whilethecastironwasconsideredoftoobrittleanaturetobesuitedforgeneraluse。*
[footnote……
LifeofBrunel,p。60。
IndeedtheRussiangovernmentbecamesopersuadedthattheEnglishnationcouldnotcarryontheirmanufactureswithoutRussianiron,thatin1770theyorderedthepricetoberaisedfrom70and80copecsperpoodto200and220
copecsperpood。*
[footnote……
SCRIVENOR,HistoryoftheIronTrade,169。
Suchbeingthecase,Cort’sattentionbecamedirectedtothesubjectinconnectionwiththesupplyofirontotheNavy,andheenteredonaseriesofexperimentswiththeobjectofimprovingthemanufactureofEnglishiron。Whattheparticularexperimentswere,andbywhatstepshearrivedatresultsofsomuchimportancetotheBritishirontrade,noonecannowtell。Allthatisknownis,thatabouttheyear1775herelinquishedhisbusinessasanavyagent,andtookaleaseofcertainpremisesatFontley,nearFareham,atthenorth-westerncornerofPortsmouthHarbour,whereheerectedaforgeandanironmill。HewasafterwardsjoinedinpartnershipbySamuelJellicoesonofAdamJellicoe,thenDeputy-PaymasterofSeamen’sWages,whichturnedout,aswillshortlyappear,amostunfortunateconnectionforCort。
Asinthecaseofotherinventions,Corttookupthemanufactureofironatthepointtowhichhispredecessorshadbroughtit,carryingitstillfurther,andimprovingupontheirprocesses。Wemayherebrieflyrecitethestepsbywhichthemanufactureofbar-ironbymeansofpit-coalhaduptothistimebeenadvanced。In1747,Mr。
FordsucceededatCoalbrookdaleinsmeltingironorewithpit-coal,afterwhichitwasrefinedintheusualwaybymeansofcokeandcharcoal。In1762,Dr。Roebuckhereaftertobereferredtotookoutapatentformeltingthecastorpigironinahearthheatedwithpit-coalbytheblastofbellows,andthenworkingtheironuntilitwasreducedtonature,ormetallized,asitwastermed;afterwhichitwasexposedtotheactionofahollowpit-coalfireurgedbyablast,untilitwasreducedtoaloopanddrawnoutintobar-ironunderacommonforge-hammer。ThenthebrothersCranege,in1766,adoptedthereverberatoryorairfurnace,inwhichtheyplacedthepigorcastiron,andwithoutblastortheadditionofanythingmorethancommonrawpit-coal,convertedthesameintogoodmalleableiron,whichbeingtakenredhotfromthereverberatoryfurnacetotheforgehammer,wasdrawnintobarsaccordingtothewilloftheworkman。PeterOnionsofMerthyrTydvil,in1783,carriedthemanufactureastagefurther,asdescribedbyhiminhispatentofthatyear。Havingchargedhisfurnace”boundwithironworkandwellannealed”withpigorfusedcastironfromthesmeltingfurnace,itwasclosedupandthedoorswerelutedwithsand。Thefirewasurgedbyablastadmittedunderneath,apparentlyforthepurposeofkeepingupthecombustionofthefuelonthegrate。ThusOnions’furnacewasofthenatureofapuddlingfurnace,thefireofwhichwasurgedbyablast。Thefirewastobekeptupuntilthemetalbecamelessfluid,and”thickenedintoakindoffroth,whichtheworkman,byopeningthedoor,mustturnandstirwithabarorotherironinstrument,andthenclosetheapertureagain,applyingtheblastandfireuntiltherewasafermentinthemetal。”Thepatentfurtherdescribesthat”astheworkmanstirsthemetal,”thescoriaewillseparate,”andtheparticlesofironwilladhere,whichparticlestheworkmanmustcollectorgatherintoamassorlump。”Thismassorlumpwasthentoberaisedtoawhiteheat,andforgedintomalleableironattheforge-hammer。
Suchwasthestageofadvancereachedinthemanufactureofbar-iron,whenHenryCortpublishedhispatentsin1783and1784。Indispensingwithablast,hehadbeenanticipatedbytheCraneges,andintheprocessofpuddlingbyOnions;butheintroducedsomanyimprovementsofanoriginalcharacter,withwhichhecombinedtheinventionsofhispredecessors,astoestablishquiteanewerainthehistoryoftheironmanufacture,and,inthecourseofafewyears,toraiseittothehigheststateofprosperity。Asearlyas1786,LordSheffieldrecognisedthegreatnationalimportanceofCort’simprovementsinthefollowingwords:-IfMr。Cort’sveryingeniousandmeritoriousimprovementsintheartofmakingandworkingiron,thesteam-engineofBoultonandWatt,andLordDundonald’sdiscoveryofmakingcokeathalfthepresentprice,shouldallsucceed,itisnotassertingtoomuchtosaythattheresultwillbemoreadvantageoustoGreatBritainthanthepossessionofthethirteencoloniesofAmerica;
foritwillgivethecompletecommandoftheirontradetothiscountry,withitsvastadvantagestonavigation。”ItisscarcelynecessaryheretopointouthowcompletelytheanticipationsofLordSheffieldhavebeenfulfilled,sanguinethoughtheymightappeartobewhenutteredsomeseventy-sixyearsago。*
[footnote……
Althoughtheironmanufacturehadgraduallybeenincreasingsincethemiddleofthecentury,itwasasyetcomparativelyinsignificantinamount。Thuswefind,fromastatementbyW。Wilkinson,datedDec。
25,1791,containedinthememorandum-bookofWm。ReynoldsofCoalbrookdale,thattheproduceinEnglandandScotlandwasthenestimatedtobeCokeFurnaces。CharcoalFurnaces。
InEngland……73producing67,548tons20producing8500tonsInScotland……12”12,480”2”1000”
85”80,028”22”9500”
AtthesametimetheannualimportofOregroundsironfromSwedenamountedtoabout20,000tons,andofbarsandslabsfromRussiaabout50,000tons,atanaveragecostof35L。aton!
WewillendeavourasbrieflyaspossibletopointouttheimportantcharacterofMr。Cort’simprovements,asembodiedinhistwopatentsof1783and1784。Inthefirsthestatesthat,after”greatstudy,labour,andexpense,intryingavarietyofexperiments,andmakingmanydiscoveries,hehadinventedandbroughttoperfectionapeculiarmethodandprocessofpreparing,welding,andworkingvarioussortsofiron,andofreducingthesameintousesbymachinery:afurnace,andotherapparatus,adaptedandappliedtothesaidprocess。”Hefirstdescribeshismethodofmakingironfor”largeuses,”suchasshanks,arms,rings,andpalmsofanchors,bythemethodofpilingandfaggoting,sincebecomegenerallypractised,bylayingbarsofironofsuitablelengths,forgedonpurpose,andtaperingsoastobethinneratoneendthantheother,laidoveroneanotherinthemannerofbricksinbuildings,sothattheendsshouldeverywhereoverlayeachother。Thefaggotssoprepared,totheamountofhalfatonmoreorless,werethentobeputintoacommonairorballingfurnace,andbroughttoaweldingheat,whichwasaccomplishedbyhismethodinamuchshortertimethaninanyhollowfire;andwhentheheatwasperfect,thefaggotswerethenbroughtunderaforge-hammerofgreatsizeandweight,andweldedintoasolidmass。Mr。Cortallegesinthespecificationthatironfor”largeruses”thusfinished,isinallrespect’spossessedofthehighestdegreeofperfection;andthatthefireintheballingfurnaceisbettersuited,fromitsregularityandpenetratingquality,togivetheironaperfectweldingheatthroughoutitswholemass,withoutfusinginanypart,thananyfireblownbyablast。