Thetinyvesselreachedherdestinationinsafety。Surelythedifficultyofatestingtrial，althoughwithamodelscrew，hadatlengthbeenovercome。Butno！Thepaddlestillpossessedtheascendency；andathousandinterests——investedcapital，useandwont，andconservativeinstincts——allstoodintheway。
Someyearsbefore——indeed，aboutthetimethatSmithtookouthispatent——CaptainEricsson，theSwede，inventedascrewpropeller。
SmithtookouthispatentinMay，1836；andEricssoninthefollowingJuly。Ericssonwasaborninventor。WhileaboyinSweden，hemadesawmillsandpumpingengines，withtoolsinventedbyhimself。Helearnttodraw，andhismechanicalcareerbegan。Whenonlytwelveyearsold，hewasappointedacadetintheSwedishcorpsofmechanicalengineers，andinthefollowingyearhewasputinchargeofasectionoftheGothaShipCanal，thenunderconstruction。Arrivedatmanhood，EricssonwentovertoEngland，thegreatcentreofmechanicalindustry。Hewasthentwenty-threeyearsold。HeenteredintopartnershipwithJohnBraithwaite，andwithhimconstructedtheNovelty，whichtookpartinthelocomotivecompetitionatRainhillonthe6thOctober，1829。TheprizewasawardedtoStephenson’sRocketonthe14th；butitwasacknowledgedbyTheTimesofthedaythattheNoveltywasStephenson’ssharpestcompetitor。
Ericssonhadawonderfullyinventivebrain，adeterminedpurpose，andagreatcapacityforwork。Whenawantwasfelt，hewasimmediatelyreadywithaninvention。TherecordsofthePatentOfficeshowhisincessantactivity。Heinventedpumpingengines，steamengines，fireengines，andcaloricengines。Hisfirstpatentfora“reciprocatingpropeller“wastakenoutinOctober1834。Toexhibititsaction，hehadasmallboatconstructedofonlyabouttwofeetlong。Itwaspropelledbymeansofascrew；
andwasshownatworkinacircularbathinLondon。Itperformeditsvoyageroundthebasinattherateofaboutthreemilesanhour。Hispatentfora“spiralpropeller，“wastakenoutinJuly1836。Thiswastheinvention，toexhibitwhichhehadavesselconstructed，ofabout40feetlong，withtwopropellers，eachof5feet3inchesdiameter。
Thisboat，theFrancisB。Ogden，provedextremelysuccessful。
Shemovedataspeedofabouttenmilesanhour。Shewasabletotowvesselsof140tonsburthenattherateofsevenmilesanhour。Perceivingthepeculiarandadmirablefitnessofthescrew-propellerforshipsofwar，EricssoninvitedtheLordsoftheAdmiraltytotakeanexcursionintowofhisexperimentalboat。“MyLords“consented；andtheAdmiraltybargecontainedonthisoccasion，SirCharlesAdam，seniorLord，SirWilliamSymonds，surveyor，SirEdwardParry，ofPolarfame，CaptainBeaufort，hydrographer，andothermenofcelebrity。ThisdistinguishedcompanyembarkedatSomersetHouse，andthelittlesteamer，withherpreciouscharge，proceededdowntherivertoLimehouseattherateofabouttenmilesanhour。Aftervisitingthesteam-enginemanufactoryofMessrs。Seawood，wheretheirLordships’favouriteapparatus，theMorganpaddle-wheel，wasincourseofconstruction，theyre-embarked，andreturnedinsafetytoSomersetHouse。
Theexperimentwasperfectlysuccessful，andyettheresultwasdisappointment。Afewdayslater，aletterfromCaptainBeaufortinformedMr。EricssonthattheirLordshipshadcertainlybeen“verymuchdisappointedwiththeresultoftheexperiment。“Thereasonforthedisappointmentwasaltogetherinexplicabletotheinventor。Itafterwardsappeared，however，thatSirWilliamSymonds，thenSurveyortotheNavy，hadexpressedtheopinionthat“evenifthepropellerhadthepowerofpropellingavessel，itwouldbefoundaltogetheruselessinpractice，becausethepowerbeingappliedatthestern，itwouldbeabsolutelyimpossibletomakethevesselsteer！“ItwillberememberedthatFrancisPettitSmith’sscrewvesselwenttoseainthecourseofthesameyear；andnotonlyfacedthewaves，butwasmadetosteerinaperfectlysuccessfulmanner。
AlthoughtheLordsoftheAdmiraltywouldnotfurtherencouragethescrewpropellerofEricsson，anofficeroftheUnitedStatesNavy，Capt。R。F。Stockton，wassosatisfiedofitssuccess，thataftermakingasingletripintheexperimentalsteamboatfromLondonBridgetoGreenwich，heorderedtheinventortobuildforhimforthwithtwoironboatsfortheUnitedStates，withsteammachineryandapropelleronthesameplan。Oneofthesevessels——theRobertF。Stockton——seventyfeetinlength，wasconstructedbyLairdandCo。，ofBirkenhead，in1838，andleftEnglandforAmericainApril1839。Capt。StocktonsofullypersuadedEricssonofhisprobablesuccessinAmerica，thattheinventoratonceabandonedhisprofessionalengagementsinEngland，andsetoutfortheUnitedStates。Itisunnecessarytomentionthefurtherimportantworksofthisgreatengineer。
Wemay，however，brieflymentionthatin1844，EricssonconstructedfortheUnitedStatesGovernmentthePrincetonscrewsteamer——thoughhewasneverpaidforhistime，labour，andexpenditure。[6]Undeterredbytheiringratitude，Ericssonneverthelessconstructedforthesamegovernment，wheninthethroesofcivilwar，thefamousMonitor，theiron-cladcupolavessel，andwassimilarlyrewarded！Heafterwardsinventedthetorpedoship——theDestroyer——theuseofwhichhasfortunatelynotyetbeenrequiredinseawarfare。Ericssonstilllives——constantlyplanningandscheming——inhishouseinBeachStreet，NewYork。Heisnowovereightyyearsoldhavingbeenbornin1803。Heisstrongandhealthy。Howhashepreservedhisvigorousconstitution？TheeditorofScribnergivestheanswer:“Thehallwindowsofhishouseareopen，winterandsummer，andnonebutopengrate-firesareallowed。Insomnianevertroubleshim，forhefallsasleepassoonashisheadtouchesthepillow。Hisappetiteanddigestionarealwaysgood，andhehasnotlostamealintenyears。Whatanexampletothemenwhoimagineitishardworkthatiskillingtheminthiscareerofunremittingindustry！“
Toreturnto“Screw“Smith，afterthesuccessfultrialofhislittlevesselatseaintheautumnof1837。Hehadmanydifficultiesyettocontendwith。Therewas，first，thedifficultyofanewinvention，andthefactthatthepaddle-boathadestablisheditselfinpublicestimation。Theengineeringandshipbuildingworldweredeadagainsthim。Theyregardedtheprojectofpropellingavesselbymeansofascrewasvisionaryandpreposterous。Therewasalsotheofficialunwillingnesstoundertakeanythingnovel，untried，andcontrarytoroutine。
Therewastheusualshakingoftheheadandtheshruggingoftheshoulders，asiftheinventorwereeitherameredreameroraprojectoreagertolayhishandsuponthepublicpurse。Thesurveyorofthenavywasopposedtotheplan，becauseoftheimpossibilityofmakingavesselsteerwhichwasimpelledfromthestern。“Screw“Smithbidedhistime；hecontinuedundaunted，andwasdeterminedtosucceed。Helabouredsteadilyonward，maintaininghisownfaithunshaken，andupholdingthefaithofthegentlemenwhohadbecomeassociatedwithhimintheprosecutionoftheinvention。
Atthebeginningof1838theLordsoftheAdmiraltyrequestedMr。
Smithtoallowhisvesseltobetriedundertheirinspection。
Twotrialswereaccordinglymade，andtheygavesomuchsatisfactionthattheadoptionofthepropellerfornavalpurposeswasconsideredasanotimprobablecontingency。Beforedecidingfinallyuponitsadoption，theLordsoftheAdmiraltywereanxioustoseeanexperimentmadewithavesselofnotlessthan200tons。Mr。Smithhadnotthemeansofaccomplishingthisbyhimself，butwiththeimprovedprospectsoftheinvention，capitalistsnowcametohisaid。OneofthemosteffectiveandenergeticofthesewasMr。HenryCurrie，banker；and，withtheassistanceofothers，the“ShipPropellerCompany“wasformed，andproceededtoerectthetestshipproposedbytheAdmiralty。
TheresultwastheArchimedes，awoodenvesselof237tonsburthen。ShewasdesignedbyMr。Pasco，laiddownbyMr。
Wimshurstinthespringof1838，waslaunchedonthe18thofOctoberfollowing，andmadeherfirsttripinMay1839。Shewasfittedwithascrewofoneturnplacedinthedeadwood，andpropelledbyapairofenginesof80-horsepower。Thevesselwasbuiltunderthepersuasionthatherperformancewouldbeconsideredsatisfactoryifaspeedwasattainedoffourorfiveknotsanhour，whereasheractualspeedwasnineandahalfknots。TheLordsoftheAdmiraltywereinvitedtoinspecttheship。AtthesecondtrialSirEdwardParry，SirWilliamSymonds，CaptainBasilHall，andotherdistinguishedpersonswerepresent。
Theresultswereagainsatisfactory。ThesuccessoftheArchimedesastonishedtheengineeringworld。EventheSurveyoroftheRoyalNavyfoundthatthevesselcouldsteer！TheLordsoftheAdmiraltycouldnolongershuttheireyes。Buttheinventioncouldnotatoncebeadopted。Itmustbetestedbythebestjudges。ThevesselwassenttoDovertobetriedwiththebestpacketsbetweenDoverandCalais。Mr。Lloyd，thechiefengineeroftheNavy，conductedtheinvestigation，andreportedmostfavourablyastothemannerofherperformance。Yetseveralyearselapsedbeforethescrewwasintroducedintotheservice。
In1840theArchimedeswasplacedatthedisposalofCaptainChappell，oftheRoyalNavy，who，accompaniedbyMr。Smith，visitedeveryprincipalportinGreatBritain。Shewasthusseenbyshipowners，marineengineers，andshipbuildersineverypartofthekingdom。Theyregardedherwithwonderandadmiration；
yetthenewmodeofnavigationwasnotspeedilyadopted。Thepaddle-wheelstillhelditsown。Thesentiment，ifnottheplantandcapital，oftheengineeringworld，wereagainsttheintroductionofthescrew。AfterthevesselhadreturnedfromhercircumnavigationofGreatBritain，shewassenttoOporto，andperformedthevoyageinsixty-eightandahalfhours，thenheldtobethequickestvoyageonrecord。ShewasthensenttotheTexelattherequestoftheDutchGovernment。ShewentthroughtheNorthHollandCanal，visitedAmsterdam，Antwerp，andotherports；andeverywherelefttheimpressionthatthescrewwasanefficientandreliablepowerinthepropulsionofvesselsatsea。
Shipbuilders，however，continuedto“fightshy“ofthescrew。
ThelateIsambardKingdonBrunelisentitledtothecreditofhavingfirstdirectedtheattentionofshipbuilderstothisimportantinvention。Hewashimselfamanoforiginalviews，freefrombias，andalwaysreadytostrikeoutafreshpathinengineeringworks。HewasbuildingalargenewironsteameratBristol，theGreatBritain，forpassengertrafficbetweenEnglandandAmerica。Hehadintendedtoconstructherasapaddlesteamer；buthearingofthesuccessoftheArchimedes，heinspectedthevessel，andwassosatisfiedwiththeperformanceofthescrewthatherecommendedhisdirectorstoadoptthismethodforpropellingtheGreatBritain。Hisadvicewasadopted，andthevesselwasalteredsoastoadaptherforthereceptionofthescrew。Thevesselwasfoundperfectlysuccessful，andonherfirstvoyagetoLondonsheattainedthespeedoftenknotsanhour，thoughthewindandbalanceoftideswereagainsther。A
fewothermerchantshipswerebuiltandfittedwiththescrew；
thePrincessRoyalatNewcastlein1840，theMargaretandSenatoratHull，andtheGreatNorthernatLondonderry，in1841。
TheLordsoftheAdmiraltymadeslowprogressinadaptingthescrewfortheRoyalNavy。SirWilliamSymonds，thesurveyorandprincipaldesignerofHerMajesty’sships，wasopposedtoallnewprojects。Hehatedsteampower，andwasutterlyopposedtoironships。Hespeaksoftheminhisjournalas“monstrous。“[7]Solongasheremainedinofficeeverythingwasdoneinaperfunctoryway。AsmallvesselnamedtheBeewasbuiltatChathamin1841，andfittedwithbothpaddlesandthescrewforthepurposesofexperiment。InthesameyeartheRattier，thefirstscrewvesselbuiltforthenavy，waslaiddownatSheerness。Althoughofonly888tonsburthen，shewasnotlauncheduntilthespringof1843。ShewasthenfittedwiththesamekindofscrewastheArchimedes，thatis，adouble-headedscrewofhalfaconvolution。Experimentswentonforaboutthreeyears，soastodeterminethebestproportionsofthescrew，andtheproportionsthenascertainedhavesincebeentheprincipalguidesofengineeringpractice。
TheRattlerwasatlengthtriedinawatertournamentwiththepaddle-steamerAlecto，andsignallydefeatedher。FrancisPettitSmith，likeGulliver，maybesaidtohavedraggedthewholeBritishfleetafterhim。Werethepaddleouronlymeansofpropulsion，ourwholenavalforcewouldbereducedtoanullity。
Hostilegunnerswouldwingapaddle-steameraseffectuailyasasportsmanwingsabird，andalltheplatingintheworldwouldrendersuchashipamerehelplesslogonthewater。
TheAdmiraltycouldnolongerdefertheuseofthisimportantinvention。Likeallgoodthings，itmadeitswayslowlyandbydegrees。Theroyalnavalauthorities，whoin1833backedthesidepaddles，havesinceadoptedthescrewinmostoftheships-of-war。Inalllongsea-goingvoyages，also，thescrewisnowthefavouritemodeofpropulsion。Screwshipsofprodigioussizearenowbuiltandlaunchedinalltheship-buildingportsofBritain，andaresentouttonavigateineverypartoftheworld。