Asidefromthedevelopmentofthemotionpictureasaspectacle，therehasgoneonanevolutioninitsuseforeducationalpurposesofwiderange，whichmustnotbeoverlooked。Infact，thisformofutilizationhasbeencarriedfurtherinEuropethaninthiscountryasameansofdemonstrationintheartsandsciences。Onemaystudyanimallife，watchasurgicaloperation，followthemovementofmachinery，takelessonsinfacialexpressionorincalisthenics。
Itseemsapitythatinmotionpicturesshouldatlasthavebeenfoundtheonlycompetitionthattheancientmarionettescannotwithstand。Butasidefromthedisappearanceofthoseentertainingpuppets，allelseisgaininthecreationofthisnewart。
TheworkattheEdisonlaboratoryinthedevelopmentofthemotionpicturewasasusualintenseandconcentrated，and，asmightbeexpected，manyoftheearlyexperimentswerequiteprimitiveintheircharacteruntilcommandhadbeensecuredofrelativelyperfectapparatus。Thesubjectsregisteredjerkilybythefilmswerecrudeandamusing，suchasofFredOtt\'ssneeze，Carmencitadancing，Italiansandtheirperformingbears，fencing，trapezestunts，horsemanship，blacksmithing——justsimplemovementswithoutanyattempttoportraythesilentdrama。
Onecuriousincidentofthisearlystudyoccurredwhen“Jim“Corbettwasaskedtoboxafewroundsinfrontofthecamera，witha“darkun“tobeselectedlocally。Thiswasagreedto，andacelebratedbruiserwasbroughtoverfromNewark。Whenthis“sparringpartner“cametofaceCorbettintheimitationringhewassoparalyzedwithterrorhecouldhardlymove。ItwasjustafterCorbetthadwononeofhisbigbattlesasaprize-fighter，andthedismayofhisopponentwasexcusable。The“boys“atthelaboratorystilllaughconsumedlywhentheytellaboutit。
Thefirstmotion-picturestudiowasdubbedbythestaffthe“BlackMaria。“Itwasanunpretentiousoblongwoodenstructureerectedinthelaboratoryyard，andhadamovableroofinthecentralpart。
Thisroofcouldberaisedorloweredatwill。Thebuildingwascoveredwithblackroofingpaper，andwasalsopaintedblackinside。Therewasnoscenerytorendergaythislugubriousenvironment，buttheblackinteriorservedasthecommonbackgroundfortheperformers，throwingalltheiractionsintohighrelief。Thewholestructurewassetonapivotsothatitcouldbeswungaroundwiththesun；andthemovableroofwasopenedsothattheaccentuatingsunlightcouldstreaminupontheactorwhosegesticulationswerebeingcaughtbythecamera。
Thesebeginningsandcruditiesareveryremotefromtheelaborateandexpensiveparaphernaliaandmachinerywithwhichtheartisfurnishedto-day。
Atthepresenttimethestudiosinwhichmotionpicturesaretakenareexpensiveandpretentiousaffairs。Animmensebuildingofglass，withallthepropertiesandstage-settingsofaregulartheatre，isrequired。TheBronxParkstudiooftheEdisoncompanycostatleastonehundredthousanddollars，whilethewell-knownhouseofPatheFreresinFrance——oneofEdison\'slicensees——makesuseofnofewerthansevenoftheseglasstheatres。Allofthelargerproducersofpicturesinthiscountryandabroademployregularstockcompaniesofactors，menandwomenselectedespeciallyfortheirskillinpantomime，although，asmostobservershaveperhapssuspected，intheactualtakingofthepicturestheperformersarerequiredtocarryonananimatedandprepareddialoguewiththesamespiritandanimationasontheregularstage。Beforesettingoutonthepreparationofapicture，thebookisfirstwritten——knowninthebusinessasascenario——givingacompletestatementastothescenery，dropsandbackground，andthesequenceofevents，dividedintoscenesasinanordinaryplay。Theseareplacedinthehandsofa“producer，“correspondingtoastage-
director，generallyanactorortheatricalmanofexperience，withahighlydevelopeddramaticinstinct。
Thevariousactorsareselected，partsareassigned，andthescene-paintersaresettoworkontheproductionofthedesiredscenery。Beforethephotographingofascene，alongseriesofrehearsalstakesplace，theincidentsbeinggoneoverandoveragainuntiltheactorsare“letterperfect。“Sopersistentaretheproducersinthematterofrehearsalsandtherefiningandelaborationofdetails，thatfrequentlyapicturethatmaybeactuallyphotographedandreproducedinfifteenminutes，mayrequiretwoorthreeweeksforitsproduction。Aftertherehearsalofascenehasadvancedsufficientlytosuitthecriticalrequirementsoftheproducer，thecameramanisinrequisition，andheisconsultedastolightingsoastoproducetherequiredphotographiceffect。
Preferably，ofcourse，sunlightisusedwheneverpossible，hencetheglassstudios；butondarkdays，andwhennight-workisnecessary，artificiallightofenormouscandle-powerisused，eithermercuryarcsorordinaryarclightsofgreatsizeandnumber。
Underallconditionsthelightisproperlyscreenedanddiffusedtosuitthecriticaleyeofthecameraman。Allbeinginreadiness，theactualpictureistaken，theactorsgoingthroughtheirrehearsedparts，theproducerstandingoutoftherangeofthecamera，andwithamegaphonetohislipsyellingouthisinstructions，imprecations，andapproval，andthecameramangrindingatthecrankofthecameraandsecuringthepicturesattherateoftwentyormorepersecond，makingafaithfulandpermanentrecordofeverymovementandeverychangeoffacialexpression。Attheendofthescenethenegativeisdevelopedintheordinaryway，andisthenreadyforuseintheprintingofthepositivesforsale。Whenafurthersceneintheplaytakesplaceinthesamesetting，andwithoutregardtoitspositionintheplot，itistakenup，rehearsed，andphotographedinthesameway，andafterwardallthescenesarecementedtogetherinthepropersequence，andformthecompletenegative。Frequently，therefore，intheproductionofamotion-pictureplay，thefirstandthelastscenemaybetakensuccessively，theonlythingnecessarybeing，ofcourse，thatafterallisdonethevariousscenesshouldbearrangedintheirproperorder。Theframes，havingservedtheirpurpose，nowgobacktothescene-painterforfurtheruse。Allpicturesarenottakeninstudios，becausewhenlightandweatherpermitandpropersurroundingscanbesecuredoutside，scenescanbestbeobtainedwithnaturalscenery——citystreets，woods，andfields。Thegreatdrawbacktothetakingofpicturesout-of-doors，however，istheinevitablecrowd，attractedbythenoveltyoftheproceedings，whichmakesthecameraman\'slifeatormentbygettingintothefieldofhisinstrument。Thecrowdsarepatient，however，andinoneEdisonpictureinvolvingtheblowingupofabridgebythevillainofthepieceandthesubstitutionofapontoonbridgebyacompanyofengineersjustintimetoallowtheheroinetopassoverinherautomobile，morethanathousandpeoplestoodaroundforalmostanentiredaywaitingforthetediousrehearsalstoendandtheactualperformancetobegin。
Frequentlylargebodiesofmenareusedinpictures，suchastroopsofsoldiers，anditisanopensecretthatforweeksduringtheBoerWarregularlyequippedBritishandBoerarmiesconfrontedeachotheronthepeacefulhillsofOrange，NewJersey，readytoenactbeforethecamerathestirringeventstoldbythecablefromtheseatofhostilities。Theseconflictswereessentiallyharmless，exceptinonecaseduringthebattleofSpionKopje，when“GeneralCronje，“
inhiseffortstofireawoodencannon，inadvertentlydroppedhisfuseintoalargeglassbottlecontaininggunpowder。Theeffectwascertainlymostdramatic，andcreatedgreatenthusiasmamongthemanyaudienceswhichviewedthecompletedproduction；buttheunfortunategeneral，whoisstillanemployee，wastakentothehospital，andevennow，twelveyearsafterward，hesayswithagrinthatwheneverhehasamomentofleisurehetakesthetimetopickafewpiecesofglassfromhisperson！
Edison\'sgreatcontributiontotheregularstagewastheincandescentelectriclamp，whichenabledtheproductionofsceniceffectsneverbeforeevendreamedof，butwhichweacceptnowwithsomuchcomplacency。Yetwiththemotionpicture，effectsaresecuredthatcouldnotbereproducedtotheslightestextentontherealstage。Thevillain，overcomebyaremorsefulconscience，seesonthewalloftheroomtheverycrimewhichhecommitted，withHIMSELFastheprincipalactor；oneoftheeasyeffectsofdoubleexposure。Thesubstantialandofttimescorpulentghostorspiritoftherealstagehasbeensucceededbyanintangiblewraith，astransparentandunsubstantialasmaybedemandedinthebestbookoffairytales——moredoubleexposure。Amanemergesfromthewaterwithasplash，ascendsfeetforemosttenyardsormore，makesagracefulcurveandlandsonaspring-board，runsdownittothebank，andhisclothesflygentlyupfromthegroundandenclosehisperson——allunthinkableinreallife，butreadilypossiblebyrunningthemotion-picturefilmbackward！Thefairyprincecommandstheprincesstoappear，consignsthebadbrotherstoinstantannihilation，turnsthewitchintoacat，conferslifeoninanimatethings；andmanymorestartlingandapparentlyincomprehensibleeffectsarecarriedoutwithactualreality，bystop-workphotography。Inonecase，whenthecommandfortheheroinetocomeforthisgiven，thecameraisstopped，theyoungwomanwalkstothedesiredspot，andthecameraisagainstarted；theeffecttotheeye——notknowingofthislittleby-play——isasifshehadinstantlyappearedfromspace。Theothereffectsareperhapsobvious，andthefieldandopportunitiesareabsolutelyunlimited。Othercuriouseffectsaresecuredbytakingthepicturesatadifferentspeedfromthatatwhichtheyareexhibited。If，forexample，asceneoccupyingthirtysecondsisreproducedintenseconds，themovementswillbethreetimesasfast，andviceversa。Manyscenesfamiliartothereader，showingautomobilestearingalongtheroadandroundingcornersatanapparentlyrecklessspeed，arereallypicturesofslowanddignifiedmovementsreproducedatahighspeed。
Briefreferencehasbeenmadetomotionpicturesofeducationalsubjects，andinthisfieldthereareverygreatopportunitiesfordevelopment。Thestudyofgeography，scenesandincidentsinforeigncountries，showingthelivesandcustomsandsurroundingsofotherpeoples，isobviouslymoreentertainingtothechildwhenactivelydepictedonthescreenthanwhenmerelydescribedinwords。Thelivesofgreatmen，theenactingofimportanthistoricalevents，thereproductionofgreatworksofliterature，ifvisuallypresentedtothechildmustnecessarilyimpresshismindwithgreaterforcethanifshownbymerewords。Wepredictthatthetimeisnotfardistantwhen，inmanyofourpublicschools，twoorthreehoursaweekwillbedevotedtothisrationalandeffectiveformofeducation。
Byapplyingmicrophotographytomotionpicturesanadditionalfieldisopenedup，onephaseofwhichmaybethestudyofgermlifeandbacteria，sothatourfuturemedicalstudentsmaybecomeasfamiliarwiththehabitsandcustomsoftheAnthraxbacillus，forexample，asofthedomesticcat。
Fromwhateverpointofviewthesubjectisapproached，thefactremainsthatinthemotionpicture，perhapsmorethanwithanyotherinvention，Edisonhascreatedanartthatmustalwaysmakeaspecialappealtothemindandemotionsofmen，andalthoughsofarithasnotadvancedmuchbeyondthefieldofamusement，itcontainsenormouspossibilitiesforseriousdevelopmentinthefuture。Letusnotthinktoolightlyofthehumblefive-centtheatrewithitsgapingcrowdfollowingwithbreathlessinterestthevicissitudesofthebeautifulheroine。Beforeusliesanundevelopedlandofopportunitywhichisdestinedtoplayanimportantpartinthegrowthandwelfareofthehumanrace。
CHAPTERXXII
THEDEVELOPMENTOFTHEEDISONSTORAGE
BATTERY
ITismorethanahundredyearssincetheelementaryprincipleofthestoragebatteryor“accumulator“
wasdetectedbyaFrenchmannamedGautherot；itisjustfiftyyearssinceanotherFrenchman，namedPlante，discoveredthatontakingtwothinplatesofsheetlead，immersingthemindilutesulphuricacid，andpassinganelectriccurrentthroughthecell，thecombinationexhibitedtheabilitytogivebackpartoftheoriginalchargingcurrent，owingtothechemicalchangesandreactionssetup。Plantecoileduphissheetsintoaveryhandycelllikealittlerollofcarpetorpastry；butthetroublewasthatthebatterytookalongtimeto“form。“Onesheetbecomingcoatedwithleadperoxideandtheotherwithfinelydividedorspongymetalliclead，theywouldreceivecurrent，andthen，evenafteralongperiodofinaction，furnishorreturnanelectromotiveforceoffrom1。85
to2。2volts。Thisabilitytostoreupelectricalenergyproducedbydynamosinhoursotherwiseidle，whetherdrivenbysteam，wind，orwater，wasadistinctadvanceintheart；butthesensationalstepwastakenabout1880，whenFaureinFranceandBrushinAmericabrokeawayfromtheslowandwearyprocessof“form-
ing“theplates，andhitonclevermethodsoffurnishingthem“readymade，“sotospeak，bydabbingredleadontolead-gridplates，justasbutterisspreadonasliceofhome-madebread。Thisbroughtthestoragebatteryatonceintouseasapractical，manufacturedpieceofapparatus；andtheworldwascaptivatedwiththeidea。ThegreatEnglishscientist，SirWilliamThomson，wentwildwithenthusiasmwhenaFaure“boxofelectricity“wasbroughtoverfromParistohimin1881containingamillionfoot-poundsofstoredenergy。Hisbiographer，Dr。SylvanusP。
Thompson，describeshimaslyingillinbedwithawoundedleg，andwatchingresultswithanincandescentlampfastenedtohisbedcurtainbyasafety-pin，andlitupbycurrentfromthelittleFaurecell。SaidSirWilliam：“Itisgoingtobeamostvaluable，practicalaffair——asvaluableaswater-cisternstopeoplewhethertheyhadorhadnotsystemsofwater-
pipesandwater-supply。“Indeed，inoneoutburstofpanegyrictheshrewdphysicistremarkedthathesawinit“arealizationofthemostardentlyandincreasinglyfeltscientificaspirationofhislife——anaspirationwhichhehardlydaredtoexpectortoseerealized。“Alittlelater，however，SirWilliam，alwayscautiousandcanny，begantodiscovertheinherentdefectsoftheprimitivebattery，astodisintegration，inefficiency，costliness，etc。，andthoughofferedtemptinginducements，declinedtolendhisnametoitsfinancialintroduction。Nevertheless，heacceptedtheprincipleasvaluable，andputthebatterytoactualuse。
Formanyyearsafterthisepisode，themodernlead-
leadtypeofbatterythusbroughtforwardwithsogreataflourishoftrumpetshadahardtimeofit。
Edison\'sattitudetowardit，evenasausefulsupplementtohislightingsystem，wasalwaysoneofscepticism，andheremarkedcontemptuouslythatthebeststoragebatteryheknewwasatonofcoal。Thefinancialfortunesofthebattery，onbothsidesoftheAtlantic，wereasvariedandasdisastrousasitsindustrial；butitdidatlastemerge，and“madegood。“
By1905，theproductionoflead-leadstoragebatteriesintheUnitedStatesalonehadreachedavaluefortheyearofnearly$3，000，000，andithasincreasedgreatlysincethattime。Thestoragebatteryisnowregardedasanimportantandindispensableadjunctinnearlyallmodernelectric-lightingandelectric-
railwaysystemsofanymagnitude；andin1909，inspiteofitsweight，ithadfoundadoptioninovertenthousandautomobilesofthetruck，deliverywagon，pleasurecarriage，andrunabouttypesinAmerica。
Edisonwatchedcloselyallthisearlierdevelopmentforaboutfifteenyears，notchanginghismindastowhatheregardedastheincurabledefectsofthelead-
leadtype，butcominggraduallytotheconclusionthatifastoragebatteryofsomeotherandbettertypecouldbebroughtforward，itwouldfulfilalltheearlyhopes，howeverextravagant，ofsuchmenasKelvinSirWilliamThomson，andwouldbecomeasnecessaryandasuniversalastheincandescentlamportheelectricmotor。Thebeginningofthepresentcenturyfoundhimathispointofnewdeparture。
Generallyspeaking，non-technicalanduninitiatedpersonshaveatendencytoregardaninventionasbeingmoreorlesstheultimateresultofsomehappyinspiration。And，indeed，thereisnodoubtthatsuchmaybethefactinsomeinstances；butinmostcasestheinventorhasintentionallysetouttoaccomplishadefiniteanddesiredresult——mostlythroughtheapplicationoftheknownlawsoftheartinwhichhehappenstobeworking。Itisrarely，however，thatamanwillstartoutdeliberately，asEdisondid，toevolvearadicallynewtypeofsuchanintricatedeviceasthestoragebattery，withonlyameagreclewandavaguestarting-point。
Inviewofthesuccessfuloutcomeoftheproblemwhich，in1900，heundertooktosolve，itwillbeinterestingtoreviewhismentalattitudeatthatperiod。
Ithasalreadybeennotedattheendofapreviouschapterthatonclosingthemagneticiron-oreconcentratingplantatEdison，NewJersey，heresolvedtoworkonanewtypeofstoragebattery。Itwasaboutthistimethat，inthecourseofaconversationwithMr。R。H。Beach，thenofthestreet-railwaydepartmentoftheGeneralElectricCompany，hesaid：
“Beach，Idon\'tthinkNaturewouldbesounkindastowithholdthesecretofaGOODstoragebatteryifarealearnesthuntforitismade。I\'mgoingtohunt。“
FrequentlyEdisonhasbeenaskedwhatheconsidersthesecretofachievement。Tothisqueryhehasinvariablyreplied：“Hardwork，basedonhardthinking。“Thelaboratoryrecordsbearthefullestwitnessthathehasconsistentlyfollowedoutthisprescriptiontotheutmost。Theperfectionofallhisgreatinventionshasbeensignalizedbypatient，persistent，andincessanteffortwhich，recognizingnoth-
ingshortofsuccess，hasresultedintheultimateaccomplishmentofhisideas。Optimisticandhopefultoahighdegree，Edisonhasthehappyfacultyofbeginningthedayasopen-mindedasachild——yesterday\'sdisappointmentsandfailuresdiscardedanddiscountedbythealluringpossibilitiesofto-morrow。
Ofallhisinventions，itisdoubtfulwhetheranyoneofthemhascalledforthmoreoriginalthought，work，perseverance，ingenuity，andmonumentalpatiencethantheonewearenowdealingwith。Oneofhisassociateswhohasbeenthroughthemanyyearsofthestorage-batterydrudgerywithhimsaid：“IfEdison\'sexperiments，investigations，andworkonthisstoragebatterywereallthathehadeverdone，Ishouldsaythathewasnotonlyanotableinventor，butalsoagreatman。Itisalmostimpossibletoappreciatetheenormousdifficultiesthathavebeenovercome。“
Fromabeginningwhichwasmadepracticallyinthedark，itwasnotuntilhehadcompletedmorethantenthousandexperimentsthatheobtainedanypositivepreliminaryresultswhatever。Throughallthisvastamountofresearchtherehadbeennoprevioussignsoftheelectricalactionhewaslookingfor。
Theseexperimentshadextendedovermanymonthsofconstantworkbydayandnight，buttherewasnobreakdownofEdison\'sfaithinultimatesuccess——
nodiminutionofhissanguineandconfidentexpectations。
Thefailureofanexperimentsimplymeanttohimthathehadfoundsomethingelsethatwouldnotwork，thusbringingthepossiblegoalalittlenearerbyaprocessofpainstakingelimination。
Now，however，afterthesemanymonthsofarduoustoil，inwhichhehadexaminedandtestedpracticallyalltheknownelementsinnumerouschemicalcombinations，theelectricactionhesoughtforhadbeenobtained，thusaffordinghimthefirstinklingofthesecretthathehadindustriouslytriedtowrestfromNature。ItshouldbeborneinmindthatfromtheveryoutsetEdisonhaddisdainedanyintentionoffollowingintheonlytracksthenknownbyemployingleadandsulphuricacidasthecomponentsofasuccessfulstoragebattery。Impressedwithwhatheconsideredtheseriousinherentdefectsofbatteriesmadeofthesematerials，andthetremendouslycomplexnatureofthechemicalreactionstakingplaceinalltypesofsuchcells，hedeterminedboldlyatthestartthathewoulddeviseabatterywithoutlead，andoneinwhichanalkalinesolutioncouldbeused——
aformwhichwould，hefirmlybelieved，beinherentlylesssubjecttodecayanddissolutionthanthestandardtype，whichaftermanysetbackshadfinallywonitswaytoanannualproductionofmanythousandsofcells，worthmillionsofdollars。
Twoorthreethousandofthefirstexperimentsfollowedthelineofhiswell-knownprimarybatteryintheattemptedemploymentofcopperoxideasanelementinanewtypeofstoragecell；butitsuseofferednoadvantages，andthehuntwascontinuedinotherdirectionsandpursueduntilEdisonsatisfiedhimselfbyavastnumberofexperimentsthatnickelandironpossessedthedesirablequalificationshewasinsearchof。
Thisimmenseamountofinvestigationwhichhadconsumedsomanymonthsoftime，andwhichhadculminatedinthediscoveryofaseriesofreactionsbetweennickelandironthatboregreatpromise，broughtEdisonmerelywithinsightofastrangeandhithertounexploredcountry。Slowlybutsurelytheresultsofthelastfewthousandsofhispreliminaryexperimentshadpointedinevitablytoanewandfruitfulregionahead。Hehaddiscoveredthehiddenpassageandheldtheclewwhichhehadsoindustriouslysought。Andnow，havingoutlinedadefinitepath，Edisonwasallafiretopushaheadvigorouslyinorderthathemightenterinandpossesstheland。
Itisatritesayingthat“historyrepeatsitself，“
andcertainlynoaxiomcarriesmoretruththanthiswhenappliedtothehistoryofeachofEdison\'simportantinventions。Thedevelopmentofthestoragebatteryhasbeennoexception；indeed，farfromotherwise，forinthetenyearsthathaveelapsedsincethetimehesethimselfandhismechanics，chemists，machinists，andexperimentersatworktodevelopapracticalcommercialcell，theoldstoryofincessantandpersistenteffortssomanifestintheworkingoutofotherinventionswasfullyrepeated。
Verysoonafterhehaddecidedupontheuseofnickelandironastheelementalmetalsforhisstoragebattery，EdisonestablishedachemicalplantatSilverLake，NewJersey，afewmilesfromtheOrangelaboratory，onlandpurchasedsometimepreviously。
Thisplacewasthesceneofthefurtherexperimentstodevelopthevariouschemicalformsofnickelandiron，andtodeterminebytestswhatwouldbebestadaptedforuseincellsmanufacturedonacom-
mercialscale。Withalittlehandfulofselectedexperimentersgatheredabouthim，Edisonsettleddowntooneofhischaracteristicstrugglesforsupremacy。
TosomeextentitwasarevivaloftheoldMenloParkdaysor，rather，nights。Someofthesewhohadworkedonthepreliminaryexperiments，withtheadditionofafewnew-comers，toiledtogetherregardlessofpassingtimeandoftenundermostdiscouragingcircumstances，butwiththatremarkableespritdecorpsthathasevermarkedEdison\'srelationswithhisco-workers，andthathascontributedsolargelytothesuccessfulcarryingoutofhisideas。
ThegroupthattookpartintheseearlyyearsofEdison\'sarduouslaborsincludedhisold-timeassistant，FredOtt，togetherwithhischemist，J。W。
Aylsworth，aswellasE。J。Ross，Jr。，W。E。Holland，andRalphArbogast，andalittlelaterW。G。Bee，allofwhomhavegrownupwiththebatteryandstilldevotetheirenergiestoitscommercialdevelopment。
Oneoftheseworkers，relatingthestrenuousexperiencesofthesefewyears，says：“Itwashardworkandlonghours，butstillthereweresomethingsthatmadelifepleasant。Oneofthemwasthesupper-hourweenjoyedwhenweworkednights。Mr。Edisonwouldhavesuppersentinaboutmidnight，andweallsatdowntogether，includinghimself。Workwasforgottenforthetime，andallhandswerereadyforfun。IhaveverypleasantrecollectionsofMr。Edisonatthesetimes。Hewouldalwaysrelaxandhelptomakeagoodtime，andonsomeoccasionsIhaveseenhimfairlyoverflowwithanimalspirits，justlikeaboyletoutfromschool。Afterthesupper-hourwasover，however，heagainbecametheserious，energeticinventor，deeplyimmersedintheworkathand。
“Hewasveryfondoftellingandhearingstories，andalwaysappreciatedajoke。Irememberonethathelikedtogetoffonusonceinawhile。Ourlightingplantwasinduplicate，andabout12。30or1o\'clockinthemorning，atthecloseofthesupper-hour，achangewouldbemadefromoneplanttotheother，involvingthegradualextinctionoftheelectriclightsandtheirslowlycominguptocandle-poweragain，thewholechangerequiringprobablyaboutthirtyseconds。Sometimes，asthiswastakingplace，Edisonwouldfoldhishands，composehimselfasifhewereinsoundsleep，andwhenthelightswerefullagainwouldapparentlywakeup，withtheremark，`Well，boys，we\'vehadafinerest；nowlet\'spitchintoworkagain。\'“
Anotherinterestingandamusingreminiscenceofthisperiodofactivityhasbeengatheredfromanotherofthefamilyofexperimenters：“Sometimes，whenMr。Edisonhadbeenworkinglonghours，hewouldwanttohaveashortsleep。ItwasoneofthefunniestthingsIeverwitnessedtoseehimcrawlintoanordinaryroll-topdeskandcurlupandtakeanap。
Iftherewasasightthatwasstillmorefunny，itwastoseehimturnoveronhisotherside，allthetimeremaininginthedesk。HewoulduseseveralvolumesofWatts\'sDictionaryofChemistryforapillow，andwefellowsusedtosaythatheabsorbedthecontentsduringhissleep，judgingfromtheflowofnewideashehadonwaking。“
Suchincidentsastheseservemerelytoillustratethelightermomentsthatstandoutinreliefagainstthemoresombrebackgroundofthestrenuousyears，for，ofalltheabsorbinglybusyperiodsofEdison\'sinventivelife，thefirstfiveyearsofthestorage-
batteryerawasoneoftheverybusiestofthemall。Itwasnotthatthereremainedanybasicprincipletobediscoveredorsimplified，forthathadalreadybeendone；butitwasintheefforttocarrytheseprinciplesintopracticethattherearosethenumerousdifficultiesthatattimesseemedinsurmountable。
But，accordingtoanotherco-worker，“Edisonseemedpleasedwhenheusedtorunupagainstaseriousdifficulty。Itwouldseemtostiffenhisbackboneandmakehimmoreprolificofnewideas。ForatimeIthoughtIwasfoolishtoimaginesuchathing，butIcouldnevergetawayfromtheimpressionthathereallyappearedhappywhenheranupagainstaserioussnag。Thatwasinmygreendays，andI
soonlearnedthatthefailureofanexperimentneverdiscourageshimunlessitisbyreasonofthecarelessnessofthemanmakingit。ThenEdisongetsdisgusted。
Ifitfailsonitsmerits，hedoesn\'tworryorfretaboutit，but，onthecontrary，regardsitasausefulfactlearned；remainscheerfulandtriessomethingelse。Ihaveknownhimtoreverseanunsuccessfulexperimentandcomeoutallright。“
TofollowEdison\'strailindetailthroughtheinnumerabletwistsandturnsofhisexperimentationandresearchonthestoragebattery，duringthepasttenyears，wouldnotbeinkeepingwiththescopeofthisnarrative，norwoulditserveanyusefulpurpose。
Besides，suchdetailswouldfillabigvolume。Thenarrative，however，wouldnotbecompletewithoutsomementionofthegeneraloutlineofhiswork，andreferencemaybemadebrieflytoafewofthechiefitems。Andlestthereaderthinkthattheword“innumerable“mayhavebeencarelesslyorhastilyusedabove，wewouldquotethereplyofoneofthelaboratoryassistantswhenaskedhowmanyexperimentshadbeenmadeontheEdisonstoragebatterysincetheyear1900：“Goodnessonlyknows！Weusedtonumberourexperimentsconsecutivelyfrom1to10，000，andwhenwegotupto10，000weturnedbackto1andranupto10，000again，andsoon。
Weranthroughseveralseries——Idon\'tknowhowmany，andhavelosttrackofthemnow，butitwasnotfarfromfiftythousand。“
Fromtheveryfirst，Edison\'sbroadideaofhisstoragebatterywastomakeperforatedmetalliccontainershavingtheactivematerialspackedtherein；
nickelhydrateforthepositiveandironoxideforthenegativeplate。Thisplanhasbeenadheredtothroughout，andhasfounditsconsummationinthepresentformofthecompletedcommercialcell，butinthemiddlegroundwhichstandsbetweentheearlycrudebeginningsandtheperfectedtypeofto-daythereliesaworldoforiginalthought，patientplodding，andachievement。
Thefirstnecessitywasnaturallytoobtainthebestandpurestcompoundsforactivematerials。Edisonfoundthatcomparativelylittlewasknownbymanufacturingchemistsaboutnickelandironoxidesofthehighgradeandpurityherequired。Henceitbecamenecessaryforhimtoestablishhisownchemicalworksandputtheminchargeofmenspeciallytrainedbyhimself，withwhomheworked。ThiswastheplantatSilverLake，abovereferredto。Here，forseveralyears，therewasceaselessactivityinthepreparationofthesechemicalcompoundsbyeveryimaginableprocessandsubsequenttesting。Edison\'schiefchemistsays：“Weleftnostoneunturnedtofindawayofmakingthosechemicalssothattheywouldgivethehighestresults。Wecarriedontheexperimentswiththetwochemicalstogether。Sometimesthenickelwouldbeaheadinthetests，andthenagainitwouldfallbehind。Tostimulateustogreaterimprovement，Edisonhungupacardwhichshowedtheresultsoftestsinmilliampere-hoursgivenbytheexperimentalelementsaswetriedthemwiththevariousgradesofnickelandironwehadmade。Thisstirredupagreatdealofambitionamongtheboystopushthefiguresup。Someofourearliesttestsshowedaround300，butasweimprovedthematerial，theygraduallycreptuptoover500。JustaboutthattimeEdisonmadeatriptoCanada，andwhenhecamebackwehadmadesuchgoodprogressthatthefigureshadcreptuptoabout1000。Iwellrememberhowgreatlyhewaspleased。“
Inspeakingofthedevelopmentofthenegativeelementofthebattery，Mr。Aylsworthsaid：“Inlikemannertheironelementhadtobedevelopedandimproved；andfinallytheiron，whichhadgenerallyenjoyedsuperiorityincapacityoveritscompanion，thenickelelement，hadtogointraininginordertoretainitslead，whichwasimperative，inordertoproduceauniformandconstantvoltagecurve。Intalkingwithmeonedayaboutthedifficultiesunderwhichwewereworkingandcontrastingthemwiththephonographexperimentation，Edisonsaid：`Inphonographicworkwecanuseourearsandoureyes，aidedwithpowerfulmicroscopes；
butinthebatteryourdifficultiescannotbeseenorheard，butmustbeobservedbyourmind\'seye！\'Andbyreasonoftheemploymentofsuchvisioninthepast，Edisonisnowabletoseequiteclearlythroughtheforestofdifficultiesaftereliminatingthemonebyone。“
Thesizeandshapeofthecontainingpocketsinthebatteryplatesorelementsandthedegreeoftheirperforationweremattersthatreceivedmanyyearsofclosestudyandexperiment；indeed，thereisstillto-
dayconstantworkexpendedontheirperfection，althoughtheirpresentgeneralformwasdecideduponseveralyearsago。Themechanicalconstructionofthebattery，asawhole，initspresentform，compelsinstantadmirationonaccountofitsbeautyandcompleteness。Mr。Edisonhassparedneitherthought，ingenuity，labor，normoneyintheefforttomakeitthemostcompleteandefficientstoragecellobtainable，andtheresultsshowthathisskill，judgment，andforesighthavelostnothingofthepowerthatlaidthefoundationof，andbuiltup，othergreatartsateachearlierstageofhiscareer。
Amongthecomplexandnumerousproblemsthatpresentedthemselvesintheevolutionofthebatterywastheoneconcerningtheinternalconductivityofthepositiveunit。Thenickelhydratewasapoorelectricalconductor，andalthoughametallicnickelpocketmightbefilledwithit，therewouldnotbethedesiredelectricalactionunlessaconductingsubstanceweremixedwithit，andsoincorporatedandpackedthattherewouldbegoodelectricalcontactthroughout。Thisprovedtobeamostknottyandintricatepuzzle——trickyandevasive——alwaysleadingonandpromisingsomething，andatthelastslippingawayleavingtheworkundone。Edison\'sremarkablepatienceandpersistenceindealingwiththistryingproblemandinfinallysolvingitsuccessfullywonforhimmorethanordinaryadmirationfromhisassociates。Oneofthem，inspeakingoftheseeminglyinterminableexperimentstoovercomethistrouble，said：“Iguessthatquestionofconductivityofthepositivepocketbroughtlotsofgrayhairstohishead。Ineverdreamedamancouldhavesuchpatienceandperseverance。AnyothermanthanEdisonwouldhavegiventhewholethingupathousandtimes，butnothe！Thingslookedawfullybluetothewholebunchofusmanyatime，buthewasalwayshopeful。IrememberonetimethingslookedsodarktomethatIhadjustaboutmadeupmymindtothrowupmyjob，butsomegoodturncamejustthenandIdidn\'t。NowI\'mgladIheldon，forwe\'vegotagreatfuture。“
ThedifficultyofobtaininggoodelectricalcontactinthepositiveelementwasindeedEdison\'schieftroubleformanyyears。Afteragreatamountofworkandexperimentationhedecideduponacertainformofgraphite，whichseemedtobesuitableforthepurpose，andthenproceededtothecommercialmanufactureofthebatteryataspecialfactoryinGlenRidge，NewJersey，installedforthepurpose。
Therewasnolackofbuyers，but，onthecontrary，thefactorywasunabletoturnoutbatteriesenough。
Thenewspapershadpreviouslypublishedarticlesshowingtheunusualcapacityandperformanceofthebattery，andpublicinteresthadthusbeengreatlyawakened。
Notwithstandingtheestablishmentofaregularroutineofmanufactureandsale，Edisondidnotceasetoexperimentforimprovement。Althoughthegraphiteapparentlydidtheworkdesiredofit，hewasnotaltogethersatisfiedwithitsperformanceandmadeextendedtrialsofothersubstances，butatthattimefoundnothingthatonthewholeservedthepurposebetter。Continuoustestsofthecommercialcellswerecarriedonatthelaboratory，aswellasmorepracticalandheavytestsinautomobiles，whichwereconstantlykeptrunningaroundtheadjoiningcountryoverallkindsofroads。AllthesetestswereverycloselywatchedbyEdison，whodemandedrigorouslythatthevarioustrialsofthebatteryshouldbecarriedonwithallstrenuousnesssoastogettheutmostresultsanddevelopanypossibleweakness。Soinsistentwasheonthis，thatifanyautomobileshouldrunseveraldayswithoutburstingatireorbreakingsomepartofthemachine，hewouldaccusethechauffeurofpickingouteasyroads。
Afterthesetestshadbeengoingonforsometime，andsomethousandsofcellshadbeensoldandweregivingsatisfactoryresultstothepurchasers，thetestsheetsandexperiencegatheredfromvarioussourcespointedtothefactthatoccasionallyacellhereandtherewouldshowupasbeingshortincapacity。
Inasmuchasthefactoryprocesseswereveryexactandcarefullyguarded，andeverycellwasmadeasuniformashumanskillandcarecouldprovide，therethusaroseaseriousproblem。Edisonconcentratedhispowersontheinvestigationofthistrouble，andfoundthatthechiefcauselayinthegraphite。Someotherminormattersalsoattractedhisattention。Whattodo，wastheimportantquestionthatconfrontedhim。Toshutdownthefactorymeantgreatlossandapparentfailure。Herealizedthisfully，buthealsoknewthattogoonwouldsimplybetoincreasethenumberofdefectivebatteriesincirculation，whichwouldultimatelyresultinapermanentclosureandrealfailure。HencehetookthecoursewhichonewouldexpectofEdison\'scommonsenseanddirectnessofaction。Hewasnotsatisfiedthatthebatterywasacompletesuccess，soheshutdownandwenttoexperimentingoncemore。
“Andthen，“saysoneofthelaboratorymen，“westartedonanotherseriesofrecord-breakingexperimentsthatlastedoverfiveyears。Imightalmostsayheart-breaking，too，forofalltheelusive，disappointingthingsoneeverhuntedforthatwastheworst。Butsecretshavetobelong-windedandroosthighiftheywanttogetawaywhenthe`OldMan\'goeshuntingforthem。Hedoesn\'tgetmadwhenhemissesthem，butjustkeepsonsmilingandfiring，andusuallybringsthemintocamp。That\'swhathedidonthebattery，forafterawholelotofworkheperfectedthenickel-flakeideaandprocess，besidesmakingthegreatimprovementofusingtubesinsteadofflatpocketsforthepositive。Healsoaddedaminorimprovementhereandthere，andnowwehaveafinerbatterythanweeverexpected。“
Intheinterim，whiletheexperimentationoftheselastfiveyearswasinprogress，manycustomerswhohadpurchasedbatteriesoftheoriginaltypecameknockingatthedoorwithordersintheirhandsforadditionaloutfitswherewithtoequipmorewagonsandtrucks。Edisonexpressedhisregrets，butsaidhewasnotsatisfiedwiththeoldcellsandwasengagedinimprovingthem。TowhichthecustomersrepliedthatTHEYwereentirelysatisfiedandreadyandwillingtopayformorebatteriesofthesamekind；
butEdisoncouldnotbemovedfromhisdetermination，althoughconsiderablepressurewasattimesbroughttobeartoswayhisdecision。
Experimentwascontinuedbeyondthepointofperadventure，andaftersomenewmachineryhadbeenbuilt，themanufactureofthenewtypeofcellwasbegunintheearlysummerof1909，andatthepresentwritingisbeingextendedasfastasthenecessaryadditionalmachinerycanbemade。Theproductisshippedoutassoonasitiscompleted。
Thenickelflake，whichisEdison\'singenioussolutionoftheconductivityproblem，isofitselfamostinterestingproduct，intenselypracticalinitsapplicationandfascinatinginitsmanufacture。Theflakeofnickelisobtainedbyelectroplatinguponametalliccylinderalternatelayersofcopperandnickel，onehundredofeach，afterwhichthecombinedsheetisstrippedfromthecylinder。Sothinarethelayersthatthissheetisonlyaboutthethicknessofavisiting-card，andyetitiscomposedoftwohundredlayersofmetal。Thesheetiscutintotinysquares，eachaboutone-sixteenthofaninch，andthesesquaresareputintoabathwherethecopperisdissolvedout。Thisreleasesthelayersofnickel，sothateachofthesesmallsquaresbecomesonehundredtinysheets，orflakes，ofpuremetallicnickel，sothinthatwhentheyaredriedtheywillfloatintheair，likethistle-down。
Intheirapplicationtothemanufactureofbatteries，theflakesareusedthroughthemediumofaspecialmachine，soarrangedthatsmallchargesofnickelhydrateandnickelflakearealternatelyfedintothepocketsintendedforpositives，andtampeddownwithapressureequaltoaboutfourtonspersquareinch。
Thisinsurescompleteandperfectcontactandconsequentelectricalconductivitythroughouttheentireunit。
Thedevelopmentofthenickelflakecontainsinitselfahistoryofpatientinvestigation，labor，andachievement，butwehavenotspaceforit，norfortracingthegreatworkthathasbeendoneindevelopingandperfectingthenumerousotherpartsandadjunctsofthisremarkablebattery。SufficeittosaythatwhenEdisonwentboldlyoutintonewterritory，aftersomethingentirelyunknown，hewasquitepreparedforhardworkandexploration。Heencounteredbothinunstintedmeasure，butkeptongoingforwarduntil，afterlongtravel，hehadfoundallthatheexpectedandaccomplishedsomethingmorebeside。NatureDIDrespondtohiswhole-
heartedappeal，and，bythetimethehuntwasended，revealedagoodstoragebatteryofentirelynewtype。
Edisonnotonlyrecognizedandtookadvantageoftheprincipleshehaddiscovered，butinadaptingthemforcommercialusedevelopedmostingeniousprocessesandmechanicalappliancesforcarryinghisdiscoveriesintopracticaleffect。Indeed，itmaybesaidthattheinventionofanenormousvarietyofnewmachinesandmechanicalappliancesrenderednecessarybyeachchangeduringthevariousstagesofdevelopmentofthebattery，fromfirsttolast，standsasalastingtributetotherangeandversatilityofhispowers。
ItisnotwithinthescopeofthisnarrativetoenterintoanydescriptionoftherelativemeritsoftheEdisonstoragebattery，thatbeingtheprovinceofacommercialcatalogue。Itdoes，however，seementirelyallowabletosaythatwhileatthepresentwritingtheteststhathavebeenmadeextendoverafewyearsonly，theirresultsandtheintrinsicvalueofthischaracteristicEdisoninventionareofsuchasubstantialnatureastopointtotheinevitablegrowthofanothergreatindustryarisingfromitsmanufacture，andtoitswide-spreadapplicationtomanyuses。
TheprincipalusethatEdisonhashadinmindforhisbatteryistransportationoffreightandpassengersbytruck，automobile，andstreet-car。ThegreatlyincreasedcapacityinproportiontoweightoftheEdisoncellmakesitparticularlyadaptableforthisclassofworkonaccountofthemuchgreaterradiusoftravelthatispossiblebyitsuse。Thelatterpointofadvantageistheonethatappealsmosttotheautomobilist，asheisthusenabledtotravel，itisasserted，morethanthreetimesfartherthaneverbeforeonasinglechargeofthebattery。
Edisonbelievesthatthereareimportantadvantagespossibleintheemploymentofhisstoragebatteryforstreet-carpropulsion。Underthepresentsystemofoperation，aplantfurnishingtheelectricpowerforstreetrailwaysmustbelargeenoughtosupplycurrentforthemaximumloadduring“rushhours，“althoughmuchofthemachinerymaybelyingidleandunproductiveinthehoursofminimumload。Bytheuseofstorage-batterycars，thisimmenseanduneconomicalmaximuminvestmentinplantcanbecutdowntoproportionsoftruecommercialeconomy，asthechargingofthebatteriescanbeconductedatauniformratewithareasonableexpenditureforgeneratingmachinery。Notonlythis，buteachcarbecomesanindependentlymovingunit，notsubjecttodelaybyreasonofageneralbreakdownofthepowerplantoroftheline。Inadditiontotheseadvantages，thestreetswouldbefreedfromtheirburdenoftrolleywiresorconduits。Toputhisideasintopractice，EdisonbuiltashortrailwaylineattheOrangeworksinthewinterof1909-10，and，inco-operationwithMr。R。H。Beach，constructedaspecialtypeofstreet-car，andequippeditwithmotor，storagebattery，andothernecessaryoperatingdevices。
Thiscarwassubsequentlyputuponthestreet-carlinesinNewYorkCity，anddemonstrateditsefficiencysocompletelythatitwaspurchasedbyoneofthestreet-carcompanies，whichhassinceorderedadditionalcarsforitslines。Thedemonstrationofthisinitialcarhasbeenwatchedwithinterestbymanyrailroadofficials，anditsperformancehasbeenofsosuccessfulanaturethatatthepresentwritingthesummerof1910ithasbeennecessarytoorganizeandequipapreliminaryfactoryinwhichtoconstructmanyothercarsofasimilartypethathavebeenorderedbyotherstreet-railwaycompanies。
Thisenterprisewillbeconductedbyacorporationwhichhasbeenspeciallyorganizedforthepurpose。
Thus，therehasbeeninitiatedthedevelopmentofanewandimportantindustrywhosepossibleultimateproportionsarebeyondtherangeofpresentcalculation。
Extensiveasthisindustrymaybecome，however，Edisonisfirmlyconvincedthatthegreatestfieldforhisstoragebatteryliesinitsadaptationtocommercialtruckingandhauling，andtopleasurevehicles，incomparisonwithwhichthestreet-carbusinessevenwithitsgreatpossibilities——willnotamounttomorethan1percent。
Edisonhaspithilysummeduphisworkandhisviewsinanarticleon“TheTo-MorrowsofElectricityandInvention“inPopularElectricityforJune，1910，inwhichhesays：“ForyearspastIhavebeentryingtoperfectastoragebattery，andhavenowrendereditentirelysuitabletoautomobileandotherwork。
Thereisabsolutelynoreasonwhyhorsesshouldbeallowedwithincitylimits；forbetweenthegasolineandtheelectriccar，noroomisleftforthem。Theyarenotneeded。Thecowandthepighavegone，andthehorseisstillmoreundesirable。Ahigherpublicidealofhealthandcleanlinessisworkingtow-
ardsuchbanishmentveryswiftly；andthenweshallhavedecentstreets，insteadofstablesmadeoutofstripsofcobblestonesborderedbysidewalks。Theworstuseofmoneyistomakeafinethoroughfare，andthenturnitovertohorses。Besidesthat，thechangewillputthehumanesocietiesoutofbusiness。
Manypeoplenowchargetheirownbatteriesbecauseoflackoffacilities；butIbelievecentralstationswillfindinthisworkverysoonthelargestpartoftheirload。TheNewYorkEdisonCompany，ortheChicagoEdisonCompany，shouldhaveasmuchcurrentgoingoutforstoragebatteriesasforpowermotors；anditwillbesosomenearday。“
CHAPTERXXIII
MISCELLANEOUSINVENTIONS
IThasbeentheendeavorinthisnarrativetogroupEdison\'sinventionsandpatentssothathisworkinthedifferentfieldscanbestudiedindependentlyandseparately。Thehistoryofhiscareerhasthereforefallennaturallyintoaseriesofchapters，eachaimingtodescribesomeparticulardevelopmentorart；and，inaway，theplanhasbeenhelpfultothewriterswhileprobablyusefultothereaders。Ithappens，however，thattheprocesshasleftavastmassofdiscoveryandinventionwhollyuntouched，andrelegatestoaconcludingbriefchaptersomeofthemostinterestingepisodesofafruitfullife。AnyonewhowillturntothelistofEdisonpatentsattheendofthebookwillfindalargenumberofthingsofwhichnotevencasualmentionhasbeenmade，butwhichatthetimeoccupiednosmallamountoftheinventor\'stimeandattention，andmanyofwhicharenowpartandparcelofmoderncivilization。Edisonhas，indeed，touchednothingthathedidnotinsomewayimprove。AsThoreausaid：“ThelawsoftheUniversearenotindifferent，butareforeveronthesideofthemostsensitive，“andthereneverwasanyonemoresensitivetothedefectsofeveryartandappliance，noranyonemoreactiveinapplyingthelawofevolution。Itisperhapsthismany-sidednessofEdisonthathasimpressedthemultitude，andthatinthe“popularvote“takenacoupleofyearsagobytheNewYorkHeraldplacedhisnameattheheadofthelistoftengreatestlivingAmericans。
Itiscuriousandpertinenttonotethatasimilarplebiscitetakenbyatechnicaljournalamongitsexpertreadershadexactlythesameresult。EvidentlythepublicdoesnotagreewiththeopinionexpressedbytheeccentricartistBlakeinhis“MarriageofHeavenandHell，“whenhesaid：“Improvementmakesstrangeroads；butthecrookedroadswithoutimprovementsareroadsofGenius。“
TheproductofEdison\'sbrainmaybedividedintothreeclasses。Thefirstembracessuchartsandindustries，orsuchapparatus，ashavealreadybeentreated。
Thesecondincludesdeviceslikethetasimeter，phonomotor，odoroscope，etc。，andothersnowtobenoted。
Thethirdembracesanumberofprojectedinventions，partiallycompletedinvestigations，inventionsinusebutnotpatented，andagreatmanycaveatsfiledinthePatentOfficeatvarioustimesduringthelastfortyyearsforthepurposeofprotectinghisideaspendingtheircontemplatedrealizationinpractice。Thesecaveatsservedtheirpurposethoroughlyinmanyinstances，buttherehaveremainedagreatvarietyofprojectsuponwhichnodefiniteactionwasevertaken。
Oneoughttoaddthecontentsofanunfinishedpieceofextraordinaryfictionbasedwhollyonnewinventionsanddevicesutterlyunknowntomankind。Somedaythenovelmaybefinished，butEdisonhasnoinclinationtogobacktoit，andsayshecannotunder-
standhowanymanisabletomakeaspeechorwriteabook，forhesimplycan\'tdoit。
Afterwhathasbeensaidinpreviouschapters，itwillnotseemsostrangethatEdisonshouldhavehundredsofdormantinventionsonhishands。Therearehumanlimitationsevenforsuchatirelessworkerasheis。Whilethepreparationofdataforthischapterwasgoingon，oneofthewritersindiscussingwithhimthevastarrayofunexploitedthingssaid：“Don\'tyoufeelasenseofregretinbeingobligedtoleavesomanythingsuncompleted？”Towhichhereplied：
“What\'stheuse？Onelifetimeistooshort，andIambusyeverydayimprovingessentialpartsofmyestablishedindustries。“Itmustsufficetospeakbrieflyofafewleadinginventionsthathavebeenworkedout，andtodismisswithscantmentionalltherest，takingjustafewitems，astypicalandsuggestive，especiallywhenEdisoncanhimselfbequotedastothem。Incidentallyitmaybenotedthatthings，notwords，arereferredto；forEdison，inadditiontoinventingtheapparatus，hasoftenhadtocointhewordtodescribeit。Alargenumberofthewordsandphrasesinmodernelectricalparlanceowetheirorigintohim。Eventhe“call-word“ofthetelephone，“Hello！”senttinglingoverthewireafewmilliontimesdailywastakenfromMenloParkbymeninstallingtelephonesindifferentpartsoftheworld，menwhohadjustlearneditatthelaboratory，andthusmadeitauniversalsesamefortelephonicconversation。
ItishardtodeterminewheretobeginwithEdison\'smiscellaneousinventions，butperhapstelegraphyhasthe“rightofline，“andEdison\'sworkinthatfieldputshimabreastofthelatestwirelessdevelopmentsthatfilltheworldwithwonder。“Iperfectedasystemoftraintelegraphybetweenstationsandtrainsinmotionwherebymessagescouldbesentfromthemovingtraintothecentraloffice；andthiswastheforerunnerofwirelesstelegraphy。ThissystemwasusedforanumberofyearsontheLehighValleyRailroadontheirconstructiontrains。Theelectricwavepassedfromapieceofmetalontopofthecaracrosstheairtothetelegraphwires；andthenproceededtothedespatcher\'soffice。InmyfirstexperimentswiththissystemItrieditontheStatenIslandRailroad，andemployedanoperatornamedKingtodotheexperimenting。Hereportedresultseveryday，andreceivedinstructionsbymail；butforsomereasonhecouldsendmessagesallrightwhenthetrainwentinonedirection，butcouldnotmakeitgointhecontrarydirection。Imadesuggestionsofeverykindtogetaroundthisphenomenon。FinallyItelegraphedKingtofindoutifhehadanysuggestionshimself；andI
receivedareplythattheonlywayhecouldproposetogetaroundthedifficultywastoputtheislandonapivotsoitcouldbeturnedaround！Ifoundthetroublefinally，andthepracticalintroductionontheLehighValleyroadwastheresult。Thesystemwassoldtoaverywealthyman，andhewouldneversellanyrightsoranswerletters。Hebecameaspiritualistsubsequently，whichprobablyexplainsit。“ItisinterestingtonotethatEdisonbecamegreatlyinterestedinthelaterdevelopmentsbyMarconi，andisanadmiringfriendandadviserofthatwell-knowninventor。
TheearlierexperimentswithwirelesstelegraphyatMenloParkweremadeatatimewhenEdisonwasgreatlyoccupiedwithhiselectric-lightinterests，anditwasnotuntilthebeginningof1886thathewasabletosparethetimetomakeapublicdemonstrationofthesystemasappliedtomovingtrains。EzraT。
Gilliland，ofBoston，hadbecomeassociatedwithhiminhisexperiments，andtheytookoutseveraljointpatentssubsequently。Thefirstpracticaluseofthesystemtookplaceonathirteen-milestretchoftheStatenIslandRailroadwiththeresultsmentionedbyEdisonabove。
Alittlelater，EdisonandGillilandjoinedforceswithLuciusJ。Phelps，anotherinvestigator，whohadbeenexperimentingalongthesamelinesandhadtakenoutseveralpatents。ThevariousinterestswerecombinedinacorporationunderwhoseauspicesthesystemwasinstalledontheLehighValleyRailroad，whereitwasusedforseveralyears。TheofficialdemonstrationtriponthisroadtookplaceonOctober6，1887，onasix-cartrainrunningtoEaston，Pennsylvania，adistanceoffifty-fourmiles。Agreatmanytelegramsweresentandreceivedwhilethetrainwasatfullspeed，includingadespatchtothe“cableking，“
JohnPender。London，England，andareplyfromhim。[17]
[17]Broadlydescribedinoutline，thesystemconsistedofaninductioncircuitobtainedbylayingstripsoftinalongthetoporroofofarailwaycar，andtheinstallationofaspecialtelegraphlinerunningparallelwiththetrackandstrungonpolesofonlymediumheight。Thetrainandalsoeachsignallingstationwereequippedwithregulationtelegraphicapparatus，suchasbattery，key，relay，andsounder，togetherwithinduction-coilandcondenser。
Inaddition，therewasatransmittingdeviceintheshapeofamusicalreed，orbuzzer。Inpractice，thisbuzzerwascontinuouslyoperatedathighspeedbyabattery。Itsvibrationswerebrokenbymeansofakeyintolongandshortperiods，representingMorsecharacters，whichweretransmittedinductivelyfromthetraincircuittothepoleline，orviceversa，andreceivedbytheoperatorattheotherendthroughahigh-resistancetelephonereceiverinsertedinthesecondarycircuitoftheinduction-coil。
Althoughthespacebetweenthecarsandthepolelinewasprobablynotmorethanaboutfiftyfeet，itisinterestingtonotethatinEdison\'searlyexperimentsatMenloParkhesucceededintransmittingmessagesthroughtheairatadistanceof580feet。Speakingofthisandofhisotherexperimentswithinductiontelegraphybymeansofkites，communicatingfromonetotheotherandthusfromthekitestoinstrumentsontheearth，Edisonsaidrecently：“Weonlytransmittedabouttwoandone-halfmilesthroughthekites。
WhathasalwayspuzzledmesinceisthatIdidnotthinkofusingtheresultsofmyexperimentson`ethericforce\'thatImadein1875。IhaveneverbeenabletounderstandhowIcametooverlookthem。
IfIhadmadeuseofmyownworkIshouldhavehadlong-distancewirelesstelegraphy。“
InoneoftheappendicestothisbookisgivenabrieftechnicalaccountofEdison\'sinvestigationsofthephenomenawhichlieattherootofmodernwirelessor“space“telegraphy，andtheattentionofthereaderisdirectedparticularlytothedescriptionandquotationstherefromthefamousnote-booksofEdison\'sexperimentsinregardtowhathecalled“ethericforce。“
Itwillbeseenthatasearlyas1875Edisondetectedandstudiedcertainphenomena——i。e。，theproductionofelectricaleffectsinnon-closedcircuits，whichforatimemadehimthinkhewasonthetrailofanewforce，astherewasnoplausibleexplanationforthembythethenknownlawsofelectricityandmagnetism。
LatercamethemagnificentworkofHertzidentifyingthephenomenaas“electromagneticwaves“intheether，anddevelopinganewworldoftheoryandsciencebaseduponthemandtheirproductionbydisruptivedischarges。
Edison\'sassertionsweretreatedwithscepticismbythescientificworld，whichwasnotthenreadyforthediscoveryandnotsufficientlyfurnishedwithcorroborativedata。Itissingular，tosaytheleast，tonotehowEdison\'sexperimentsparalleledandprovedinadvancethosethatcamelater；andevenhisapparatussuchasthe“darkbox“formakingthetinysparksvisibleasthewavesimpingedonthereceiverbearscloseanalogywithsimilarapparatusemployedbyHertz。Indeed，asEdisonsentthedark-boxapparatustotheParisExpositionin1881，andletBatchelorrepeattherethepuzzlingexperiments，itseemsbynomeansunlikelythat，eitherdirectlyoronthereportofsomefriend，HertzmaythushavereceivedfromEdisonamostvaluablesuggestion，theinventoraidingthephysicistinopeningupawonderfulnewrealm。Inthisconnection，indeed，itisveryinterestingtoquotetwogreatauthorities。InMay，1889，atameetingoftheInstitutionofElectricalEngineersinLondon，Dr。nowSirOliverLodgeremarkedinadiscussiononapaperofhisownonlightningconductors，embracingtheHertzianwavesinitstreatment：
“ManyoftheeffectsIhaveshown——sparksinunsuspectedplacesandotherthings——havebeenobservedbefore。HenryobservedthingsofthekindandEdisonnoticedsomecuriousphenomena，andsaiditwasnotelectricitybut`ethericforce\'thatcausedthesesparks；
andthematterwasratherpooh-poohed。ItwasasmallpartofTHISVERYTHING；onlythetimewasnotripe；theoreticalknowledgewasnotreadyforit。“
Againinhis“SignallingwithoutWires，“ingivingthehistoryofthecohererprinciple，Lodgeremarks：
“SparksidenticalinallrespectswiththosediscoveredbyHertzhadbeenseeninrecenttimesbothbyEdisonandbySylvanusThompson，beingstyled`ethericforce\'bytheformer；buttheirtheoreticsignificancehadnotbeenperceived，andtheyweresomewhatscepticallyregarded。“DuringthesamediscussioninLondon，in1889，SirWilliamThomsonLordKelvin，aftercitingsomeexperimentsbyFaradaywithhisinsulatedcageattheRoyalInstitution，said：“HisFaraday\'sattentionwasnotdirectedtolookforHertzsparks，orprobablyhemighthavefoundthemintheinterior。Edisonseemstohavenoticedsomethingofthekindinwhathecalled`ethericforce。\'
Hisname`etheric\'maythirteenyearsagohaveseemedtomanypeopleabsurd。Butnowweareallbeginningtocalltheseinductivephenomena`etheric。\'
“WithwhichtestimonyfromthegreatKelvinastohispriorityindeterminingthevitalfact，andwiththeevidencethatasearlyas1875hebuiltapparatusthatdemonstratedthefact，Edisonisprobablyquitecontent。
ItshouldperhapsbenotedatthispointthatacuriouseffectobservedatthelaboratorywasshowninconnectionwithEdisonlampsatthePhiladelphiaExhibitionof1884。Itbecameknowninscientificparlanceasthe“Edisoneffect，“showingacuriouscurrentconditionordischargeinthevacuumofthebulb。IthassincebeenemployedbyFleminginEnglandandDeForestinthiscountry，andothers，asthebasisforwireless-telegraphapparatus。Itisinrealityaminuterectifierofalternatingcurrent，andanalogoustothosewhichhavesincebeenmadeonalargescale。
WhenRoentgencameforwardwithhisdiscoveryofthenew“X“-rayin1895，Edisonwasreadyforit，andtookupexperimentationwithitonalargescale；someofhisworkbeingrecordedinanarticleintheCenturyMagazineofMay，1896，whereagreatdealofdatamaybefound。Edisonsayswithregardtothiswork：
“WhentheX-raycameup，Imadethefirstfluoroscope，usingtungstateofcalcium。Ialsofoundthatthistungstatecouldbeputintoavacuumchamberofglassandfusedtotheinnerwallsofthechamber；andiftheX-rayelectrodeswereletintotheglasschamberandapropervacuumwasattained，youcouldgetafluorescentlampofseveralcandle-power。Istartedintomakeanumberoftheselamps，butIsoonfoundthattheX-rayhadaffectedpoisonouslymyassistant，Mr。Dally，sothathishaircameoutandhisfleshcommencedtoulcerate。Ithenconcludeditwouldnotdo，andthatitwouldnotbeaverypopularkindoflight；soIdroppedit。
“AtthetimeIselectedtungstateofcalciumbecauseitwassofluorescent，Isetfourmentomakingallkindsofchemicalcombinations，andthuscollectedupwardof8000differentcrystalsofvariouschemicalcombinations，discoveringseveralhundreddifferentsub-
stanceswhichwouldfluorescetotheX-ray。SofarlittlehadcomeofX-raywork，butitaddedanotherlettertothescientificalphabet。Idon\'tknowanythingaboutradium，andIhavelotsofcompany。“
TheElectricalEngineerofJune3，1896，containsaphotographofMr。Edisontakenbythelightofoneofhisfluorescentlamps。ThesamejournalinitsissueofApril1，1896，showsanEdisonfluoroscopeinusebyanobserver，inthenowfamiliaranduniversalformsomewhatlikeastereoscope。ThisapparatusasinventedbyEdisonconsistsofaflaringbox，curvedatoneendtofitcloselyovertheforeheadandeyes，whiletheotherendoftheboxisclosedbyapaste-
boardcover。Ontheinsideofthisisspreadalayeroftungstateofcalcium。Byplacingtheobjecttobeobserved，suchasthehand，betweenthevacuum-tubeandthefluorescentscreen，the“shadow“isformedonthescreenandcanbeobservedatleisure。Theapparatushasprovedinvaluableinsurgeryandhasbecomeanacceptedpartoftheequipmentofmodernsurgery。
In1896，attheElectricalExhibitionintheGrandCentralPalace，NewYorkCity，givenundertheauspicesoftheNationalElectricLightAssociation，thousandsandthousandsofpersonswiththeuseofthisapparatusinEdison\'spersonalexhibitwereenabledtoseetheirownbones；andtheresultantpublicsensationwasgreat。Mr。MallorytellsacharacteristicstoryofEdison\'sownshareinthememorableexhibit：“TheexhibitwasannouncedforopeningonMonday。OntheprecedingFridayalltheapparatus，whichincludedalargeinduction-coil，wasshippedfromOrangetoNewYork，andonSaturdayafternoonEdison，accompaniedbyFredOtt，oneofhisassistants，andmyself，wentovertoinstallitsoastohaveitreadyforMondaymorning。Hadeverythingbeennormal，afewhourswouldhavesufficedforcompletionofthework，butoncomingtotestthebigcoil，itwasfoundtobeabsolutelyoutofcommission，havingbeensoseriouslyinjuredastonecessitateitsentirerewinding。Itbeingsummer-time，allthemachineshopswerecloseduntilMondaymorning，andtherewereseveralmilesofwiretobewoundonthecoil。Edisonwouldnotconsiderapostponementoftheexhibition，sotherewasnothingtodobutgotoworkandwinditbyhand。Wemanagedtofindalathe，buttherewasnopower；soeachofus，includingEdison，tookturnsrevolvingthelathebypullingonthebelt，whiletheothertwoattendedtothewindingofthewire。WeworkedcontinuouslyallthroughthatSaturdaynightandalldaySundayuntilevening，whenwefinishedthejob。Idon\'tremembereverbeingconsciousofmoremusclesinmylife。IguessEdisonwastiredalso，buthetookitveryphilosophically。“ThiswasapparentlythefirstpublicdemonstrationoftheX-raytotheAmericanpublic。
Edison\'sore-separationworkhasbeenalreadyfullydescribed，butthestorywouldhardlybecompletewithoutareferencetosimilarworkingoldextraction，datingbacktotheMenloParkdays：“Igotupamethod，“saysEdison，“ofseparatingplacergoldbyadryprocess，inwhichIcouldworkeconomicallyoreasleanasfivecentsofgoldtothecubicyard。Ihadseveralcar-loadsofdifferentplacersandssenttomeandprovedIcoulddoit。SomepartieshearingIhadsucceededindoingsuchathingwenttoworkandgotholdofwhatwasknownastheOrtizminegrant，twelvemilesfromSantaFe，NewMexico。Thismine，accordingtothereportsofseveralminingengineersmadeinthelastfortyyears，wasconsideredoneoftherichestplacerdepositsintheUnitedStates，andvariousschemeshadbeenputforwardtobringwaterfromthemountainsfortymilesawaytoworkthoseimmensebeds。ThereportsstatedthattheMexicanshadbeenpanninggoldforahundredyearsoutofthesedeposits。
“Thesepartiesnowmadearrangementswiththestockholdersorownersofthegrant，andwithme，toworkthedepositsbymyprocess。AsIhadhadsomepreviousexperiencewiththestatementsofminingmen，IconcludedIwouldjustsenddownasmallplantandprospectthefieldbeforeputtingupalargeone。
ThisIdid，andIsenttwoofmyassistants，whomI
couldtrust，downtothisplacetoerecttheplant；andstartedtosinkshaftsfiftyfeetdeepalloverthearea。
Wesoonlearnedthattherichgravel，insteadofbeingspreadoveranareaofthreebysevenmiles，andrichfromthegrassrootsdown，wasspreadoveraspaceofabouttwenty-fiveacres，andthateventhisdidnotaveragemorethantencentstothecubicyard。Thewholeplacerwouldnotgivemorethanoneandone-
quartercentspercubicyard。Asmybusinessarrangementshadnotbeenveryperfectlymade，Ilosttheusualamount。“
Goingtoanotherextreme，wefindEdisongrapplingwithoneofthebiggestproblemsknowntotheauthoritiesofNewYork——thedisposalofitsheavysnows。
ItisneedlesstosaythatwitnessingtheordinaryslowandcostlyprocedurewouldputEdisononhismettle。
“OnetimewhentheyhadasnowblockadeinNewYorkIstartedtobuildamachinewithBatchelor——abigtruckwithasteam-engineandcompressoronit。
Wewouldrunalongthestreet，gatherallthesnowupinfrontofus，passitintothecompressor，anddeliverlittleblocksoficebehindusinthegutter，takingone-
tenththeroomofthesnow，andnotinconveniencinganybody。Wecouldthustakecareofasnow-stormbydiminishingthebulkofmaterialtobehandled。
Thepreliminaryexperimentwemadewasdroppedbecausewewentintootherthings。Themachinewouldgoasfastasahorsecouldwalk。“
Edisonhasalwaystakenakeeninterestinaerialflight，andhasalsoexperimentedwithaeroplanes，hispreferenceincliningtothehelicoptertype，asnotedinthenewspapersandperiodicalsfromtimetotime。
Thefollowingstatementfromhimreferstoatypeofaeroplaneofgreatnoveltyandingenuity：“JamesGordonBennettcametomeandaskedthatItrysomeprimaryexperimentstoseeifaerialnavigationwasfeasiblewith`heavier-than-air\'machines。Igotupamotorandputitonthescalesandtriedalargenumberofdifferentthingsandcontrivancesconnectedtothemotor，toseehowitwouldlightenitselfonthescales。Igotsomedataandmadeupmymindthatwhatwasneededwasaverypowerfulengineforitsweight，insmallcompass。SoIconceivedofanengineemployingguncotton。Itookalotoftickerpapertape，turneditintoguncottonandgotupanenginewithanarrangementwherebyIcouldfeedthisgun-
cottonstripintothecylinderandexplodeitinsideelectrically。Thefeedtookplacebetweentwocopperrolls。Thecopperkeptthetemperaturedown，sothatitcouldonlyexplodeuptothepointwhereitwasincontactwiththefeedrolls。Itworkedprettywell；
butoncethefeedrolldidn\'tsaveit，andtheflamewentthroughandexplodedthewholerollandkickedupsuchabadexplosionIabandonedit。Buttheideamightbemadetowork。“
Turningfromtheairtotheearth，itisinterestingtonotethattheintroductionoftheundergroundEdisonsysteminNewYorkmadeanappealtoinventiveingenuityandthatoneofthedifficultieswasmetasfollows：“WhenwefirstputthePearlStreetstationinoperation，inNewYork，wehadcast-ironjunction-
boxesattheintersectionsofallthestreets。Onenight，orabouttwoo\'clockinthemorning，apolicemancameinandsaidthatsomethinghadexplodedatthecornerofWilliamandNassaustreets。Ihappenedtobeinthestation，andwentouttoseewhatitwas。Ifoundthatthecoverofthemanhole，weighingabout200pounds，hadentirelydisappeared，buteverythinginsidewasintact。Ithadevenstrippedsomeofthethreadsofthebolts，andwecouldneverfindthatcover。Iconcludeditwaseitherleakageofgasintothemanhole，orelsetheacidusedinpicklingthecastinghadgivenoffhydrogen，andairhadleakedin，makinganexplosivemixture。Asthiswasaprettyseriousproblem，andaswehadagoodmanyofthemanholes，itworriedmeverymuchforfearthatitwouldberepeatedandthecompanymighthavetopayalotofdamages，especiallyindistrictslikethataroundWilliamandNassau，wherethereareagoodmanypeopleabout。Ifanexplosiontookplaceinthedaytimeitmightliftafewofthemup。However，I
gotaroundthedifficultybyputtingalittlebottleofchloroformineachbox，corkedup，withaslightholeinthecork。Thechloroformbeingvolatileandveryheavy，settledintheboxanddisplacedalltheair。I
haveneverheardofanexplosioninamanholewherethischloroformhadbeenused。Carbontetrachloride，nowmadeelectricallyatNiagaraFalls，isverycheapandwouldbeidealforthepurpose。“
Edisonhasneverpaidmuchattentiontowarfare，andhasingeneraldisdainedtodevelopinventionsforthedestructionoflifeandproperty。Someyearsago，however，hebecamethejointinventoroftheEdison-
Simstorpedo，withMr。W。ScottSims，whosoughthisco-operation。Thisisadirigiblesubmarinetorpedooperatedbyelectricity。Inthetorpedoproper，whichissuspendedfromalongfloatsoastobesubmergedafewfeetunderwater，areplacedthesmallelectricmotorforpropulsionandsteering，andtheexplosivecharge。Thetorpedoiscontrolledfromtheshoreorshipthroughanelectriccablewhichitpaysoutasitgoesalong，andalloperationsofvaryingthespeed，reversing，andsteeringareperformedatthewillofthedistantoperatorbymeansofcurrentssentthroughthecable。DuringtheSpanish-AmericanWarof1898
EdisonsuggestedtotheNavyDepartmenttheadoptionofacompoundofcalciumcarbideandcalciumphosphite，whichwhenplacedinashellandfiredfromagunwouldexplodeassoonasitstruckwaterandignite，producingablazethatwouldcontinueseveralminutesandmaketheshipsoftheenemyvisibleforfourorfivemilesatsea。Moreover，theblazecouldnotbeextinguished。