Theidea，thusearlyborn，layinoblivionuntil1760，whenthedaguerreotypewasagainclearlyindicatedinabookpublishedinParis，writtenbyacertainTiphaniedelaRoche，undertheanagrammatictitleofGiphantie。Stilllater，atthebeginningofthepresentcentury，wefindThomasWedgwood，SirHumphryDavy，andJamesWatt，makingexperimentsontheactionoflightuponnitrateofsilver；andonlywithinthelastfewmonthsasilveredcopper-platehasbeenfoundamongsttheoldhouseholdlumberofMatthewBoultonWatt’spartner，havingonitarepresentationoftheoldpremisesatSoho，apparentlytakenbysomesuchprocess。*
[footnote……
TheplateisnowtobeseenattheMuseumofPatentsatSouthKensington。Intheaccountwhichhasbeenpublishedoftheabovediscoveryitisstatedthat”anoldmanofninetyrecentlydeadorstillaliverecollected，orrecollects，thatWattandothersusedtotakeportraitsofpeopleinadark?room；andthereisaletterextantofSirWilliamBeechey，beggingtheLunarSocietytodesistfromtheseexperiments，as，weretheprocesstosucceed，itwouldruinportrait-painting。”
Inlikemannertheinventionoftheelectrictelegraph，supposedtobeexclusivelymodern，wasclearlyindicatedbySchwenterinhisDelasementsPhysico-Mathematiques，publishedin1636；andhetherepointedouthowtwoindividualscouldcommunicatewitheachotherbymeansofthemagneticneedle。Acenturylater，in1746，LeMonnierexhibitedaseriesofexperimentsintheRoyalGardensatParis，showinghowelectricitycouldbetransmittedthroughironwire950
fathomsinlength；andin1753wefindoneCharlesMarshallpublishingaremarkabledescriptionoftheelectrictelegraphintheScotsMagazine，underthetitleof’AnexpeditionsMethodofconveyingIntelligence。’Again，in1760，wefindGeorgeLouisLesage，professorofmathematicsatGeneva，promulgatinghisinventionofanelectrictelegraph，whichheeventuallycompletedandsettoworkin1774。Thisinstrumentwascomposedoftwenty-fourmetallicwires，separatefromeachotherandenclosedinanon-conductingsubstance。
Eachwireendedinastalkmountedwithalittleballofelder-woodsuspendedbyasilkthread。Whenastreamofelectricity，nomatterhowslight。，wassentthroughthewire，theelder-ballattheoppositeendwasrepelled，suchmovementdesignatingsomeletterofthealphabet。AfewyearslaterwefindArthurYoung，inhisTravelsinFrance，describingasimilarmachineinventedbyaM。LomondofParis，theactionofwhichhealsodescribes。*
[footnote……”l6thOct。l787。IntheeveningtoM。Lomond，averyingeniousandinventivemechanic，whohasmadeanimprovementofthejennyforspinningcotton。Commonmachinesaresaidtomaketoohardathreadforcertainfabrics，butthisformsitlooseandspongy。Inelectricityhehasmadearemarkablediscovery：youwritetwoorthreewordsonapaper；hetakesitwithhimintoaroom，andturnsamachineinclosedinacylindricalcase，atthetopofwhichisanelectrometer，asmallfinepithball；awireconnectswithasimilarcylinderandelectrometerinadistantapartment；andhiswife，byremarkingthecorrespondingmotionsoftheball，writesdownthewordstheyindicate；fromwhichitappearsthathehasformedanalphabetofmotions。Asthelengthofthewiremakesnodifferenceintheeffect，acorrespondencemightbecarriedonatanydistance：
withinandwithoutabesiegedtown，forinstance；orforapurposemuchmoreworthy，andathousandtimesmoreharmless，betweentwoloversprohibitedorpreventedfromanybetterconnexion。Whatevertheusemaybe，theinventionisbeautiful。”——ArthurYoung’sTravelsinFrancein1787-8-9。London，1792，4to。ed。p。65。
Intheseandsimilarcases，thoughtheideawasbornandthemodeloftheinventionwasactuallymade，itstillwaitedtheadventofthescientificmechanicalinventorwhoshouldbringittoperfection，andembodyitinapracticalworkingform。
Someofthemostvaluableinventionshavedescendedtouswithoutthenamesoftheirauthorshavingbeenpreserved。Wearetheinheritorsofanimmenselegacyoftheresultsoflabourandingenuity，butweknownotthenamesofourbenefactors。Whoinventedthewatchasameasureroftime?Whoinventedthefastandloosepulley?Whoinventedtheeccentric?Who，asksamechanicalinquirer，*
[footnote……
Mechanic’sMagazine，4thFeb。1859。”inventedthemethodofcuttingscrewswithstocksanddies?Whoeverhemightbe，hewascertainlyagreatbenefactorofhisspecies。Yetaddsthewriterhisnameisnotknown，thoughtheinventionhasbeensorecent。”Thisisnot，however，thecasewithmostmoderninventions，thegreaternumberofwhicharemoreorlessdisputed。
Whowasentitledtothemeritofinventingprintinghasneveryetbeendetermined。WeberandSenefelderbothlaidclaimtotheinventionoflithography，thoughitwasmerelyanoldGermanartrevived。Eventheinventionofthepenny-postagesystembySirRowlandHillisdisputed；Dr。GrayoftheBritishMuseumclaimingtobeitsinventor，andaFrenchwriterallegingittobeanoldFrenchinvention。*
[footnote……
AwriterintheMondesays：——”Theinventionofpostage-stamps。isfarfrombeingsomodernasisgenerallysupposed。ApostalregulationinFranceoftheyear1653，whichhasrecentlycometolight，givesnoticeofthecreationofpre-paidticketstobeusedforParisinsteadofmoneypayments。Theseticketsweretobedatedandattachedtotheletterorwrappedroundit，insuchamannerthatthepostmancouldremoveandretainthemondeliveringthemissive。Thesefranksweretobesoldbytheportersoftheconvents，prisons，colleges，andotherpublicinstitutions，atthepriceofonesou。”
TheinventionofthesteamboathasbeenclaimedonbehalfofBlascodeGaray，aSpaniard，Papin，aFrenchman，JonathanHulls，anEnglishman，andPatrickMillerofDalswinton，aScotchman。TheinventionofthespinningmachinehasbeenvariouslyattributedtoPaul，Wyatt，Hargreaves，Higley，andArkwright。Theinventionofthebalance-springwasclaimedbyHuyghens，aDutchman，Hautefeuille，aFrenchman，andHooke，anEnglishman。Thereisscarcelyapointofdetailinthelocomotivebutisthesubjectofdispute。Thustheinventionoftheblast-pipeisclaimedforTrevithick，GeorgeStephenson，GoldsworthyGurney，andTimothyHackworth；thatofthetubularboilerbySeguin，Stevens，Booth，andW。H。James；thatofthelink-motionbyJohnGray，HughWilliams，andRobertStephenson。
Indeedmanyinventionsappeartobecoincident。Anumberofmindsareworkingatthesametimeinthesametrack，withtheobjectofsupplyingsomewantgenerallyfelt；and，guidedbythesameexperience，theynotunfrequentlyarriveatlikeresults。Ithassometimeshappenedthattheinventorshavebeenseparatedbygreatdistances，sothatpiracyonthepartofeitherwasimpossible。ThusHadleyandGodfreyalmostsimultaneouslyinventedthequadrant，theoneinLondon，theotherinPhiladelphia；andtheprocessofelectrotypingwasinventedatthesametimebyMr。Spencer，aworkingchemistatLiverpool，andbyProfessorJacobiatSt。Petersburg。Thesafety-lampwasacoincidentinvention，madeaboutthesametimebySirHumphryDavyandGeorgeStephenson；andperhapsastillmoreremarkableinstanceofacoincidentdiscoverywasthatoftheplanetNeptunebyLeverrieratParis，andbyAdamsatCambridge。
Itisalwaysdifficulttoapportionthedueshareofmeritwhichbelongstomechanicalinventors，whoareaccustomedtoworkuponeachother’shintsandsuggestions，aswellasbytheirownexperience。
Someideaofthisdifficultymaybeformedfromthefactthat，inthecourseofourinvestigationsastotheoriginoftheplaningmachine——oneofthemostusefulofmoderntools——wehavefoundthatithasbeenclaimedonbehalfofsixinventors——FoxofDerby，RobertsofManchester，MatthewMurrayofLeeds，SpringofAberdeen，ClementandGeorgeRennieofLondon；andtheremaybeotherclaimantsofwhomwehavenotyetheard。Butmostmechanicalinventionsareofaverycompositecharacter，andareleduptobythelabourandthestudyofalongsuccessionofworkers。ThusSavaryandNewcomenleduptoWatt；Cugnot，Murdock，andTrevithicktotheStephensons；andMaudslaytoClement，Roberts，Nasmyth，Whitworth，andmanymoremechanicalinventors。Thereisscarcelyaprocessintheartsbuthasinlikemannerengagedmindaftermindinbringingittoperfection。”Thereisnothing，”saysMr。Hawkshaw，”reallyworthhavingthatmanhasobtained，thathasnotbeentheresultofacombinedandgradualprocessofinvestigation。Agiftedindividualcomesacrosssomeoldfootmark，stumblesonachainofpreviousresearchandinquiry。Hemeets，forinstance，withamachine，theresultofmuchpreviouslabour；hemodifiesit，pullsittopieces，constructsandreconstructsit，andbyfurthertrialandexperimenthearrivesatthelongsought-forresult。”*
[footnote……
InauguralAddressdeliveredbeforetheInstitutionofCivilEngineers，l4thJan。1862。
Butthemakingoftheinventionisnotthesoledifficulty。Itisonethingtoinvent，saidSirMarcBrunel，andanotherthingtomaketheinventionwork。ThuswhenWatt，afterlonglabourandstudy，hadbroughthisinventiontocompletion，heencounteredanobstaclewhichhasstoodinthewayofotherinventors，andforatimepreventedtheintroductionoftheirimprovements，ifnotledtotheirbeinglaidasideandabandoned。Thiswasthecircumstancethatthemachineprojectedwassomuchinadvanceofthemechanicalcapabilityoftheagethatitwaswiththegreatestdifficultyitcouldbeexecuted。
WhenlabouringuponhisinventionatGlasgow，Wattwasbaffledandthrownintodespairbytheclumsinessandincompetencyofhisworkmen。WritingtoDr。Roebuckononeoccasion，hesaid，”Youaskwhatistheprincipalhindranceinerectingengines?Itisalwaysthesmith-work。”Hisfirstcylinderwasmadebyawhitesmith，ofhammeredironsolderedtogether，buthavingusedquicksilvertokeepthecylinderair-tight，itdroppedthroughtheinequalitiesintotheinterior，and”playedthedevilwiththesolder。”Yet，inefficientthoughthewhitesmithwas，Wattcouldillsparehim，andwefindhimwritingtoDr。Roebuckalmostindespair，saying，”Myoldwhite-ironmanisdead！”feelinghislosstobealmostirreparable。HisnextcylinderwascastandboredatCarron，butitwassountruethatitprovednexttouseless。Thepistoncouldnotbekeptsteamtight，notwithstandingthevariousexpedientswhichwereadoptedofstuffingitwithpaper，cork，putty，pasteboard，andoldhat。EvenafterWatthadremovedtoBirmingham，andhehadtheassistanceofBoulton’sbestworkmen，Smeatonexpressedtheopinion，whenhesawtheengineatwork，thatnotwithstandingtheexcellenceoftheinvention，itcouldneverbebroughtintogeneralusebecauseofthedifficultyofgettingitsvariouspartsmanufacturedwithsufficientprecision。ForalongtimewefindWatt，inhisletters，complainingtohispartnerofthefailureofhisenginesthrough”villainousbadworkmanship。”
Sometimesthecylinders，whencast，werefoundtobemorethananeighthofaninchwideratoneendthantheother；andundersuchcircumstancesitwasimpossibletheenginecouldactwithprecision。
Yetbetterworkcouldnotbehad。First-rateworkmeninmachinerydidnotasyetexist；theywereonlyinprocessofeducation。Nearlyeverythinghadtobedonebyhand。Thetoolsusedwereofaveryimperfectkind。Afewill-constructedlathes，withsomedrillsandboring-machinesofarudesort，constitutedtheprincipalfurnitureoftheworkshop。Yearsafter，whenBrunelinventedhisblock-machines，considerabletimeelapsedbeforehecouldfindcompetentmechanicstoconstructthem，andevenaftertheyhadbeenconstructedhehadequaldifficultyinfindingcompetenthandstoworkthem。*
[footnote……
BEAMISH’SMemoirofSirI。M。Brunel，79，80。
Wattendeavouredtoremedythedefectbykeepingcertainsetsofworkmentospecialclassesofwork，allowingthemtodonothingelse。
Fatherswereinducedtobringuptheirsonsatthesamebenchwiththemselves，andinitiatetheminthedexteritywhichtheyhadacquiredbyexperience；andatSohoitwasnotunusualforthesamepreciselineofworktobefollowedbymembersofthesamefamilyforthreegenerations。Inthiswayasgreatadegreeofaccuracyofamechanicalkindwasarrivedatwaspracticableunderthecircumstances。Butnotwithstandingallthiscare，accuracyoffittingcouldnotbesecuredsolongasthemanufactureofsteam-engineswasconductedmainlybyhand。Therewasusuallyaconsiderablewasteofsteam，whichtheexpedientsofchewedpaperandgreasedhatpackedoutsidethepistonwereinsufficienttoremedy；anditwasnotuntiltheinventionofautomaticmachine-toolsbythemechanicalengineersabouttobementioned，thatthemanufactureofthesteam-enginebecameamatterofcomparativeeaseandcertainty。Wattwascompelledtorestsatisfiedwithimperfectresults，arisingfromimperfectworkmanship。Thus，writingtoDr。Smallrespectingacylinder18
inchesindiameter，hesaid，”attheworstplacethelongdiameterexceededtheshortbyonlythree-eighthsofaninch。”Howdifferentfromthestateofthingsatthisday，whenacylinderfivefeetwidewillberejectedasapieceofimperfectworkmanshipifitbefoundtovaryinanypartmorethanthe80thpartofaninchindiameter！
Notfiftyyearssinceitwasamatteroftheutmostdifficultytosetanenginetowork，andsometimesofequaldifficultytokeepitgoing。Thoughfittedbycompetentworkmen，itoftenwouldnotgoatall。Thentheforemanofthefactoryatwhichitwasmadewassentfor，andhewouldalmostlivebesidetheengineforamonthormore；
andaftereasingherhereandscrewingherupthere，puttinginanewpartandalteringanoldone，packingthepistonandtighteningthevalves，themachinewouldatlengthbegottowork。*
[footnote……
Therewasthesameclumsinessinallkindsofmill-workbeforetheintroductionofmachine-tools。Wehaveheardofapieceofmachineryoftheoldschool，thewheelsofwhich，whensettowork，madesuchaclatterthattheownerfearedtheenginewouldfalltopieces。Theforemanwhosetitagoing，afterworkingatituntilhewasalmostindespair，atlastgaveitup，saving，”Ithinkwehadbetterleavethecogstosettletheirdifferenceswithoneanother：theywillgrindthemselvesrightintime！”