AconsiderablebranchofbusinesscarriedonbythefirmofSharp，Roberts，andCo。wasthemanufactureofironbilliard-tables，whichwereconstructedwithalmostperfecttruthbymeansofMr。Roberts’splaning-machine，andbecamealargearticleofexport。Butamuchmoreimportantandremunerativedepartmentwasthemanufactureoflocomotives，whichwasbegunbythefirmshortlyaftertheopeningoftheLiverpoolandManchesterRailwayhadmarkedthisasoneofthechiefbranchesoffuturemechanicalengineering。Mr。Robertsadroitlyseizedtheopportunitypresentedbythisnewfieldofinventionandenterprise，anddevotedhimselfforatimetothecarefulstudyofthelocomotiveanditspowers。Asearlyastheyear1829wefindhimpresentingtotheManchesterMechanics’Instituteamachineexhibitingthenatureoffrictionuponrailroads，insolutionoftheproblemthenunderdiscussioninthescientificjournals。Inthefollowingyearhepatentedanarrangementforcommunicatingpowertobothdriving-wheelsofthelocomotive，atalltimesintheexactproportionsrequiredwhenturningtotherightorleft，——anarrangementwhichhassincebeenadoptedinmanyroadlocomotivesandagriculturalengines。Inthesamepatentwillbefoundembodiedhisinventionofthesteam-brake，whichwasalsoafavouriteideaofGeorgeStephenson，sinceelaboratedbyMr。MacConnelloftheLondonandNorth-WesternRailway。In1834，Sharp，Roberts，andCo。beganthemanufactureoflocomotivesonalargescale；andthecompactnessoftheirengines，theexcellenceoftheirworkmanship，andthenumerousoriginalimprovementsintroducedinthem，speedilysecuredfortheenginesoftheAtlasfirmahighreputationandaverylargedemand。
AmongMr。Roberts’simprovementsmaybementionedhismethodofmanufacturingthecrankaxle，ofweldingtherimandtyresofthewheels，andhisarrangementandformofthewrought-ironframingandaxle-guards。Hissystemoftempletsandgauges，bymeansofwhicheverypartofanengineortendercorrespondedwiththatofeveryotherengineortenderofthesameclass，wasasgreatanimprovementasMaudslay’ssystemofuniformityofpartsinotherdescriptionsofmachinery。
Inconnectionwiththesubjectofrailways，wemayalludeinpassingtoMr。Roberts’sinventionoftheJacquardpunchingmachine——aself-actingtoolofgreatpower，usedforpunchinganyrequirednumberofholes，ofanypitchandtoanypattern，withmathematicalaccuracy，inbridgeorboilerplates。Theoriginofthisinventionwassomewhatsimilartothatoftheself-actingmule。ThecontractorsfortheConwayTubularBridgewhileunderconstruction，in1848，weregreatlyhamperedbycombinationsamongsttheworkmen，andtheydespairedofbeingabletofinishthegirderswithinthetimespecifiedinthecontract。Thepunchingoftheironplatesbyhandwasatediousandexpensiveaswellasaninaccurateprocess；andtheworkwasproceedingsoslowlythatthecontractorsfounditabsolutelynecessarytoadoptsomenewmethodofpunchingiftheyweretofinishtheworkintime。IntheiremergencytheyappealedtoMr。Roberts，andendeavouredtopersuadehimtotakethematterup。
Heatlengthconsentedtodoso，andevolvedthemachineinquestionduringhisevening’sleisure——forthemostpartwhilequietlysippinghistea。Themachinewasproduced，thecontractorswereenabledtoproceedwiththepunchingoftheplatesindependentoftherefractorymen，andtheworkwasexecutedwithadespatch，accuracy，andexcellencethatwouldnototherwisehavebeenpossible。OnlyafewyearssinceMr。RobertsaddedausefulcompaniontotheJacquardpunchingmachine，inhiscombinedself-actingmachineforshearingironandpunchingbothwebsofangleorTironsimultaneouslytoanyrequiredpitch；thoughthismachine，likeotherswhichhaveproceededfromhisfertilebrain，isaheadevenofthisfast-manufacturingage，andhasnotyetcomeintogeneraluse，butiscertaintodosobeforemanyyearshaveelapsed。
Theseinventionsweresurelyenoughforonemantohaveaccomplished；