\"Whentheaxishasreachedapointatwhichitinclinesbutabouttwelvedegrees,itwillbecomenecessarytofilltheantarcticreservoirinJuneandtheArcticOceaninDecember,inordertocheckthestraightening,sinceotherwiseitmightgetbeyondtheperpendicularandswingtheotherway。Whenthismotioniscompletelyarrested,IsuggestthatweblowuptheAleutianIslesandenlargeBeringStrait,soastoallowwhatcorrespondstotheAtlanticGulfStreaminthePacifictoentertheArcticArchipelago,whichIhavecalculatedwillraisetheaveragetemperatureofthatentireregionaboutthirtydegrees,therebystillfurtherincreasingtheamountofavailableland。
\"Oceancurrents,beingtheresultoftheprevailingwinds,whichwillbemoreregularthanatpresent,canbecountedupontocontinuepracticallyastheyare。Itmaynotbeplaintoyouwhythetradewindsdonotblowtowardstheequatorduesouthandnorth,sincetheequatorhasmuchthesameeffectonairthatastovehasinthecentreofaroom,causinganascendingcurrenttowardstheceiling,whichmovesoffinstraightlinesinalldirectionsonreachingit,itsplacebeingtakenbycoldcurrentsmovinginoppositedirectionsalongthefloor。Picturetoyourselvestheascendingcurrentsattheequatormovingofftothepolesfromwhichtheycame。Astheymovenorththeyarecontinuallycomingtopartsoftheglobehavingsmallercirclesoflatitudethanthosetheyhaveleft,andthereforenotmovedforwardasrapidlybytheearth\'sdailyrotationasthelatitudesnearertheequator。Thewindsconsequentlyrunaheadofthesurface,andsomoveeastofnorth——theearthturningtowardstheeast——whiletheheaviercoldersurfacecurrents,rushingtowardstheequatortotaketheplaceoftheascendingcolumn,comingfromregionswherethesurfacewhirlscomparativelyslowlytothosewhereitisrotatingfaster,arecontinuallyleftbehind,andsomovesouthwest;whilesouthoftheequatoracorrespondingmotionresults。Thoughthisisnotthemostexactexplanation,itmayservetomaketheactionclear。Iwilladd,thatifanyoneprefersacolderorawarmerclimatethanthatoftheplaceinwhichhelives,heneedonlygonorthorsouthforanhour;
or,ifheprefershisownlatitude,hecanriseafewthousandfeetintheair,ordescendtooneoftheworked—outcoal—mineswhicharenowusedassanitariums,andsecurehisobjectbyaslightchangeofaltitude。Letusspeedthedepartureofrackingchangesandextremesofclimate,andpreparetowelcomewhatwebelieveprevailsinparadise——namely,everlastingspring。\"
AppendedtotheaddresswasthereportoftheGovernmentExaminingCommittee,whichran:\"WehavecriticallyexaminedtheTerrestrialAxisStraighteningCompany\'sfiguresandcalculations,alsoitsstatementsinvolvingnaturalphilosophy,physics,andastronomy,allofwhichwefindcorrect,andherebyapprove。
[Signed]\"FortheCommittee:
\"HENRYCHELMSFORDCORTLANDT,\"Chairman。\"
TheBoardofDirectorshavingratifiedtheactsofitsofficers,andpassedcongratulatoryresolutions,themeetingadjournedsinedie。
CHAPTERIV。
PROF。CORTLANDT\'SHISTORICALSKETCHOFTHEWORLD
INA。D。2000。
Prof。Cortlandt,preparingahistoryofthetimesatthebeginningofthegreatterrestrialandastronomicalchange,wroteasfollows:\"Thisperiod——A。D。2000——isbyfarthemostwonderfultheworldhasasyetseen。Theadvanceinscientificknowledgeandattainmentwithinthememory,ofthepresentgenerationhasbeensostupendousthatitcompletelyovershadowsallthathaspreceded。Alltimesinhistoryandallperiodsoftheworldhavebeenremarkableforsomedistinctiveorcharacteristictrait。ThefeatureoftheperiodofLouisXIVwasthesplendourofthecourtandthecentralizationofpowerinParis。Theyear1789markedthedeclineofthepowerofcourtsandtheevolutionofgovernmentbythepeople。So,bythespreadofrepublicanideasandthegreatadvanceinscience,educationhasbecomeuniversal,forwomenaswellasformen,andthisismorethaneveramechanicalage。
\"Withincreasedknowledgeweareconstantlycomingtorealizehowlittlewereallyknow,andarealsocontinuallyfindingmanifestationsofforcesthatatfirstseemlikeexceptionstoestablishedlaws。Thisis,ofcourse,broughtaboutbythemodifyinginfluenceofsomeothernaturallaw,thoughmanyofthesewehavenotyetdiscovered。
\"Electricityinitsvariedformsdoesallwork,havingsupersededanimalandmanuallabourineverything,andmanhasonlytodirect。ThegreatestingenuitynexttofindingnewusesforthisalmostomnipotentfluidhasbeendisplayedininducingtheforcesofNature,andeventhesun,toproduceit。Beforedescribingthefeaturesofthisperfectionofcivilization,letusreviewthestepsbywhichsocietyandthepoliticalworldreachedtheirpresentstate。
\"AtthecloseoftheFranco—PrussianWar,in1871,ContinentalEuropeenteredupontheconditionofanarmedcamp,whichlastedfornearlyhalfacentury。TheprimarycauseofthiswasthemutualdislikeandjealousyofFranceandGermany,eachofwhichstrovetohavealargerandbetterequippednationaldefencethantheother。Therewerealsomanyothercauses,astheambitionoftheRussianCzar,supportedbyhiscountry\'svastthoughimperfectlydevelopedresourcesandpracticallyunlimitedsupplyofmen,onephaseofwhichwastheconstantfermentintheBalkanPeninsula,andanotherRussia\'sschemesforextensioninAsia;
anotherwasthegeneraldesireforcoloniesinAfrica,inwhichoneContinentalpowerprettyeffectuallyblockedanother,andthelatentdistrustinsidetheTripleAlliance。England,meanwhile,preservedawiseandprofitableneutrality。
\"Thesetremendoussacrificesforarmaments,bothonlandandwater,hadfar—reachingresults,and,asweseeitnow,werecloudswithsilverlinings。Thedemandforhardenedsteelprojectiles,nickel—steelplates,andlightandalmostunbreakablemachinery,wasagreatincentivetoimprovementinmetallurgywhilethenecessityforcompactandsafelycarriedammunitiongreatlystimulatedchemicalresearch,andledtothediscoveryofexplosiveswhosepowersnoobstaclecanresist,andincidentallytoothermoreusefulthings。
\"Furthermechanicalandscientificprogress,however,suchasflyingmachinesprovidedwiththesehighexplosives,andasphyxiatingbombscontainingcompressedgasthatcouldbefiredfromgunsordroppedfromtheair,intervened。Theformerwouldhavelaideverycityinthedust,andthelattermighthavealmostexterminatedtherace。Thesediscoveriesprovidentiallypreventedhostilities,sothatthe\'GreatWar,\'solongexpected,nevercame,andtherivalnationshadtheirpainsfornothing,or,rather,forothersthanthemselves。
\"Letusnowexaminethepoliticalandethnologicalresults。
Hundredsofthousands,oftheflowerofContinentalEuropewerekilledbyoverworkandshortrations,andmillionsofdesirableandoften——unfortunatelyforus——undesirablepeopleweredriventoemigration,nearlyallofwhomcametoEnglish—speakingterritory,greatlyincreasingourproductivenessandpower。As,wehaveseen,thejealousyoftheContinentalpowersforoneanothereffectuallypreventedtheirextendingtheirinfluenceorprotectoratestoothercontinents,whichjealousywasconsiderablyaidedbythesmallbutdestructivewarsthatdidtakeplace。Hightaxesalsomadeitmoredifficultforthemoneyedmentoinvestincolonizingordevelopmentcompanies,whicharesooftentheforerunnersofabsorption;whiletheUnitedStates,withhercoal——ofwhichtheMediterraneanstateshavescarcelyany——otherresources,andlowtaxes,which,thoughnecessary,canbenothingbutanevil,hasbeenabletoexpandnaturallyasnoothernationeverhasbefore。
\"ThishasgiventheEnglish—speakers,especiallytheUnitedStates,afreehand,renderingenforcementoftheMonroedoctrineeasy,andstartedEnglishalongwaytowardsbecomingtheuniversallanguage,whileallformerlyunoccupiedlandisnowownedbythosespeakingit。
\"Atthecloseofourcivilwar,in1865,wehadbut3,000,000
squaremiles,andapopulationof34,000,000。Thecountrystaggeredbeneathacolossaldebtofover$4,000,000,000,hadanexpensivebutessentiallyperishablenavy,andtherewasanominousfeelingbetweenthesections。ThepurchaseofAlaskain1867,bywhichweaddedoverhalfamillionsquaremilestoourterritory,markedtheresumptionoftheforwardmarchoftheUnitedStates。Twenty—fiveyearslater,atthepresidentialcampaignof1892,thedebthadbeenreducedto$900,000,000,deductingthesinkingfund,andthechargeforpensionshadaboutreacheditsmaximumandsoonbegantodecrease,thoughnooneobjectedtoanyamountofrewardforbonafidesoldierswhohadhelpedtosavethecountry。Thecountry\'swealthhadalsoenormouslyincreased,whilethepopulationhadgrownto65,000,000。Ourancestorshad,completedorinbuilding,anavyofwhichnonationneedbeashamed;and,thoughoccasionallymarredbyhardtimes,therewasgeneralprosperity。
\"GraduallythedifferentStatesofCanada——orprovinces,astheywerethencalled——cametorealizethattheirfuturewouldbefargranderandmoregloriousinunionwiththeUnitedStatesthanseparatedfromit;andalsothattheirsympathywasfarstrongerfortheirnearestneighboursthanforanyoneelse。OnebyonetheseNorthernStatesmadeknowntheirdesireforconsolidationwiththeUnion,retainingcompletecontroloftheirlocalaffairs,ashavetheolderStates。TheyweregladlywelcomedbyourGovernmentandpeople,andpossiblerivalsbecamethebestoffriends。Precedingandalsofollowingthis,theStatesofMexico,CentralAmerica,andpartsofSouthAmerica,tiringoftheincessantrevolutionsanddifficultiesamongthemselves,whichhadprettyconstantlylookeduponusasabigbrotheronaccountofourmaintenanceoftheMonroedoctrine,begantoagitateforannexation,knowingtheywouldretaincontroloftheirlocalaffairs。InthistheywerevigorouslysupportedbytheAmericanresidentsandproperty—holders,whoknewthattheirpossessionswoulddoubleinvaluethedaytheUnitedStatesConstitutionwassigned。
\"Thus,inthefirstplace,bytheencouragementofourpeople,andlatterly,apparently,byitsownvolition,theUnionhasincreasedenormouslyinpower,tillitnowembraces10,000,000
squaremiles,andhasafreeandenlightenedpopulationof300,000,000。ThoughtheUnionestablishedbyWashingtonandhiscontemporarieshasattainedsuchtremendousproportions,itsgrowthisbynomeansfinished;andasaresultofmodernimprovements,itislessofajourneynowtogofromAlaskatotheOrinocothanitwasfortheFatherofhisCountrytotravelfromNewYorkorPhiladelphiatothesiteofthecitynamedinhishonour。
\"Adequateandreallyrapidtransportationfacilitieshavedonemuchtobindthedifferentpartsofthecountrytogether,andtorubofftheedgesoflocalprejudice。Thoughwealwaysfavourpeace,nonationwouldthinkofopposingtheexpressedwishesoftheUnitedStates,andourmoralpowerforgoodistremendous。
ThenameJaphetmeansenlargement,andtheprophecyseemsabouttobeliterallyfulfilledbythesehisdescendants。ThebankruptsufferingofsomanyEuropeanContinentalpowershadalsootherresults。Itenabledthesocialists——whohaveneverbeenabletoseebeyondthemselves——toforcetheirgovernmentsintosellingtheircoloniesintheEasternhemispheretoEngland,andtheirislandsintheWesterntous,inordertorealizeuponthem。
WiththeadditionofCanadatotheUnitedStatesanditslosstotheBritishEmpire,thelandpossessionsofthetwopowersbecameaboutequal,ourUnionbeingatriflethelarger。AlldangerofwarbeingremovedbytheCanadianchange,ahealthfulandfriendlycompetitiontookitsplace,thenationscompetingintheirgrowthondifferenthemispheres。EnglandeasilyaddedlargeareasinAsiaandAfrica,whiletheUnitedStatesgrewaswehaveseen。Theraceisstill,inasense,neck—and—neck,andtheEnglish—speakerstogetherpossessnearlyhalftheglobe。Theworld\'srecentrateofprogresswouldhavebeenimpossiblewithoutthisapproximationtoauniversallanguage。ThecausesthatcheckmatedtheContinentalpowershaveceasedtoexist。
Manymillionsofmenwhoseprincipalthoughthadbeentodestroyothermembersoftheracebecameproducers,butitwasthentoolate,fortheheavyarmamentshaddonetheirwork。
\"Letusnowglanceatthetimesastheyare,andseehowthebusinessoflifeistransacted。ManhattanIslandhassomethingover2,500,000inhabitants,andissurroundedbyabeltofpopulation,severalmileswide,of12,000,000more,ofwhichitisthefocus,sothattheentirecitycontainsmorethan14,500,000souls。TheseveralhundredsquaremilesoflandandwaterforminggreaterNewYorkareperfectlyunitedbynumerousbridges,tunnels,andelectricferries,whilethecity\'sgreatnaturaladvantageshavebeenenhancedandbeautifiedbyeveryingeniousdevice。Nomainavenueinthenewersectionsislessthantwohundredfeetwide,containingshadeandfruittrees,abridle—path,broadsidewalks,andopenspacesforcarriagesandbicycles。Severalfinediagonalstreetsandbreathing—squareshavealsobeenprovidedintheoldersections,andtheexistingparkshavebeensupplementedbyintermediateones,allbeingconnectedbyparkwaystoformcontinuouschains。
\"Thehollowmastsofourships——toglanceatanotherphaseenpassant——carrywindmillsinsteadofsails,throughwhichthewindperformsthework,ofstoringagreatpartoftheenergyrequiredtorunthematsea,whiletheyaredischargingorloadingcargoinport;anditcan,ofcourse,worktobetteradvantagewhiletheyarestationarythanwhentheyarerunningbeforeit。Theseturbinesaremadeentirelyoflightmetal,andfoldwhennotinuse,sothatonlytheframesarevisible。Sometimesthesealsofoldandarehoused,orwhollydisappearwithinthemast。
Steam—boilersarealsoplacedatthefociofhugeconcavemirrors,oftenahundredfeetindiameter,therequiredheatbeingsuppliedbythesun,withoutsmoke,insteadofbybulkyanddirtycoal。ThisdiscoverygavecommercialvaluetoSaharaandothertropicaldeserts,whicharenowdesirableformill—sitesandforgeneratingpower,onaccountofthedirectnesswithwhichtheyreceivethesun\'sraysandtheirfreedomfromclouds。MileaftermileAfricahasbeenwonfortheusesofcivilization,tillgreatstretchesthatwereconsideredimpassibleareasproductiveasgardens。Ourcondensers,whichcompress,cool,andrarefyair,enablingtravellerstoobtainwaterandevenicefromtheatmosphere,aregreataidsindesertexploration,removingabsolutelytheprincipaldistressoftheancientcaravan。Theerstwhile\'DarkContinent\'hasalargerwhitepopulationnowthanNorthAmericahadahundredyearsago,andhasthisadvantageforthefuture,thatitcontains11,600,000squaremiles,whileNorthAmericahaslessthan9,000,000。Everypartoftheglobewillsoonsustainaboutaslargeandprosperousapopulationastheamountofenergyitreceivesfromthesunandothersourceswillwarrant;publicdebtsandtheefficiencyofthegovernmentsbeingthevariableelements。
\"TherabbitsinAustralia,andthefarmoreobjectionablepoisonoussnakesinSouthAmericaandIndia,havebeenexterminatedbythecaptureofafewdozenofthecreaturesintheinfesteddistricts,theirinoculationwiththevirussimilartothemurustiphi,tuberculosisoranyothercontagious—germcomplainttowhichthespeciestreatedwasparticularlysusceptible,andthereleaseoftheseindividualswhenthediseasewasseentobetakinghold。Therabbitsandserpentsreleasedatoncereturnedtotheiroldhaunts,carryingtheplaguefarandwide。Theunfortunaterabbitsweregreatlycommiseratedevenbythemedicosthatwieldedthedeath—dealingsyringe;but,fortunatelyforthemselves,theydiedeasily。Thereptiles,perhapsonaccountofthewiderdistributionofthenervecentres,hadmorelingeringbutnotpainfuldeaths,often,whileinarticulomortis,leavingtheholeswithwhichtheyseemedtoconnecttheirdiscomfort,andmakingafinalstrugglealongtheground,onlytodiemorequicklyasaresultoftheirexertions。Wehaveappliedthisalsotothepotato—bug,locust,andotherinsectpests,novictimbeingtoosmallfortheubiquitous,subtlegerm,which,properlycultivatedandutilized,hasbecomeoneofman\'sbestfriends。
\"Wehavemicrobeteststhatshowusasunmistakablywhetherthegermsofanyparticulardisease——likemalaria,typhoid,orscarletfever——arepresentintheair,aslitmus—papershowsalkalinityofasolution。Wealsoinoculateasapreventiveagainsttheseandalmostallothergermdiseases,withthesamesuccessthatwevaccinateforsmallpox。
\"Themedicinalpropertiesofallarticlesoffoodaresowellunderstoodalso,thatmostcuresarebroughtaboutsimplybydieting。This,remindsmeofthemistakesperpetratedonafriendofminewhocalledinDr。Grave—Powders,oneoftheold—schoolphysicians,tobetreatedforinsomniaanddyspepsia。
Thisoldnumskullrestrictedhisdiet,gavehimhugedosesofmedicine,anddecidedmostlearnedlythathewasdailygrowingworse。Concludingthathehadbutashorttimetolive,myfriendthrewawaythenauseatingmedicines,atewhateverhehadanaturaldesirefor,andwassoonaswellasever——theobviousmoralofwhichis,thatwecangetwhatevertreatmentweneedmostbeneficiallyfromourfood。Ourphysiciansaremostseriousandthoughtfulmen。Theyneverclaimtobeinfallible,butstudyscientificallytoincreasetheirknowledgeandimprovethemethodsoftreatment。Asaresultofthis,freshair,regularexerciseforbothsexes,withbetterconditions,andthepreservationofthelivesofchildrenthatformerlydiedbythousandsfrompreventablecauses,thephysique,especiallyofwomen,iswonderfullyimproved,andtheaveragelongevityisalreadyoversixty。
\"Oursocialstructure,tobebrief,isbasedonscience,ortheconservationofenergy,astheGreekphilosopherspredicted。Itwasknowntothemthatacertainamountofpowerwouldproduceonlyacertainamountofwork——thatis,theweightofaclockindescendingoraspringinuncoilingreturnstheoreticallytheamountofworkexpendedinraisingorcoilingit,andinnopossiblewaycanitdomore。Inpractice,onaccountoffriction,etc。,weknowitdoesless。Thislaw,beinginvariable,ofcourselimitsus,asitdidArchimedesandPythagoras;wehavesimplyutilizedsourcesofpowerthattheirclumsyworkmenallowedtoescape。Ofthefourprincipalsources——food,fuel,wind,andtide——includingharnessedwaterfalls,thelasttwodobyfarthemostwork。Muchoftheelectricalenergyineverythunderstormisalsocapturedandcondensedinourcapaciousstoragebatteries,asnaturalhygeiaintheformofrainwasandisstillcaughtinourcountrycisterns。Everyexposedplaceiscrownedbyaclusterofhugewindmillsthatliftwatertosomepondorreservoirplacedashighaspossible。Everystiffbreeze,therefore,raisesmillionsoftonsofwaterwhichoperatehydraulicturbinesasrequired。
Incidentallythesestoragereservoirs,byincreasingthesurfaceexposedtoevaporationandtheconsequentrainfall,haveaverybeneficialeffectonthedryregionsintheinteriorofthecontinent,andinsomecaseshavealmostsupersededirrigation。
Thewindmillanddynamothusutilizebleakmountain—topsthat,tilltheirdiscovery,seemedtobebutindifferentsuccessesinDameNature\'sdomain。Theelectricitygeneratedbythese,inconnectionwiththatobtainedbywaterfalls,tidaldynamos,thunderstorms,chemicalaction,andslow—movingquadruple—expansionsteamengines,providesthepowerrequiredtorunourelectricshipsandwater—spiders,railways,andstationaryandportablemotors,forheatingthecableslaidalongthebottomofourcanalstopreventtheirfreezinginwinter,andforalmosteveryconceivablepurpose。Sometimesamanhasawindmillonhisroofforlightandheat;then,theharderthewintryblastsmayblowthebrighterandwarmerbecomesthehouse,thecurrentpassingthroughastoragebatterytomakeitmoresteady。Theoperationofourordinaryelectricrailwaysisverysimple:thecurrentistakenfromanoverhead,side,orunderneathwire,directlythroughtheair,withouttheinterventionofatrolley,andthefastcars,fortheyarenolongerrunintrains,makefivemilesaminute。Theentireweightofeachcarbeingusedforitsowntraction,itcanascendverysteepgrades,andcanattainhighspeedorstopveryquickly。
\"Anotherformisthemagneticrailway,onwhichthecarsarewedge—shapedatbothends,andmovedbyhugemagnetsweighingfourthousandtonseach,placedfiftymilesapart。Onpassingamagnet,thenatureoftheelectricitychargingacarisautomaticallychangedfrompositivetonegative,orviceversa,tothatofthemagnetjustpassed,sothatitrepelswhilethenextattracts。Thesuccessivemagnetsarechargedoppositely,thesectionsbeingdividedhalfwaybetweenbyinsulators,thenatureoftheelectricityineachsectionbeinggovernedbythechargeinthemagnet。Topreventonekindofelectricityfromunitingwithandneutralizingthatinthenextsectionbypassingthroughthecaratthemomentoftransit,thereisa\"deadstretch\"offiftyyardswithrailsnotchargedatallbetweenthesections。Thischangeinthenatureoftheelectricityisrepeatedautomaticallyeveryfiftymiles,andobviatesthenecessityofrevolvingmachinery,therailsaidingcommunication。
\"Magnetismbeingpracticallyasinstantaneousasgravitation,theonlylimitationstospeedaretheelectricalpressureatthemagnets,theresistanceoftheair,andthedangerofthewheelsburstingfromcentrifugalforce。Thefirstcanseeminglybeincreasedwithoutlimit;theatmosphericresistanceisabouttobereducedbyrunningthecarshermeticallysealedthroughapartialvacuuminasteelandtoughenedglasstube;whilethethirdhasbeenremovedindefinitelybytheuseofgalvanizedaluminum,whichbearsaboutthesamerelationtoordinaryaluminumthatsteeldoestoiron,andwhichhastwicethetensilestrengthandbutonethirdtheweightofsteel。Insomecasestherailsaremadeturnedin,sothatitwouldbeimpossibleforacartoleavethetrackwithouttheroad—bed\'sbeingtotallydemolished;butinmostcasesthisisfoundtobeunnecessary,fornothroughlinehasacurveonitsvaststretcheswitharadiusoflessthanhalfamile。Rails,onehundredandsixtypoundstotheyard,aresetingroovedsteelties,whichinturnareheldbyaconcreteroad—bedconsistingofbrokenstoneandcement,makingspreadingrailsandlooseballastimpossible。A
largeincreaseincapitalwasnecessaryfortheseimprovements,theeliminationofcurvesbeingthemostlaboriouspart,requiringbridges,cuttings,andembankmentsthatdwarfthePyramidsandwouldhavemadetheancientPharaohsopentheireyes;butwiththelowrateofinterestonbonds,theslightcostofpower,andgreatincreaseinbusiness,theventurewasasuccess,andwearenowinsightoffurtheradvancesthatwillenableatravellerinahighlatitudemovingwesttokeeppacewiththesun,and,shouldhewishit,tohaveunendingday。\"
CHAPTERV。
DR。CORTLANDT\'SHISTORYCONTINUED。
\"Inmarinetransportationwehavetwomethods,oneforfreightandanotherforpassengers。Theold—fashioneddeeplyimmersedshiphasnotchangedradicallyfromthesteamandsailingvesselsofthelastcentury,exceptthatelectricityhassupersededallothermotivepowers。Steamersgraduallypassedthroughthefivehundred—,sixhundred—,andsevenhundred—foot—longclass,withotherdimensionsinproportion,tilltheirlengthexceededonethousandfeet。Thesewereveryfastships,crossingtheAtlanticinfourandahalfdays,andwerealmostassteadyashouses,ineventheroughestweather。
\"Shipsatthisperiodoftheirdevelopmenthadalsopassedthroughthetwinandtriplescrewstagetothequadruple,allfourtogetherdevelopingonehundredandfortythousandindicatedhorse—power,andbeingdrivenbysteam。This,ofcourse,involvedsacrificingthebestpartoftheshiptoherengines,andaveryheavyidleinvestmentwhileinport。Storagebatteries,withplatescomposedofleadoriron,constantlyincreasinginsize,hadreachedafairstateofdevelopmentbythecloseofthenineteenthcentury。
\"Duringtheseconddecadeofthetwentiethcenturytheengineersdecidedtotrytheplanofrunninghalfofatransatlanticliner\'sscrewsbyelectricitygeneratedbytheenginesfordrivingtheotherswhiletheshipwasinport,thishavingbeenasuccessalreadyonasmallerscale。Foratimethisplangavegreatsatisfaction,sinceitdiminishedtheamountofcoaltobecarriedandtheconsequentchangeofdisplacementatsea,andenabledtheshiptobeworkedwithasmallernumberofmen。Thebatteriescouldalso,ofcourse,bedistributedalongtheentirelength,andplacedwherespacewasleastvaluable。
\"Theconstructionofsuchhugevesselscalledformuchgovernmentalriverandharbourdredging,andashipdrawingthirty—fivefeetcannowenterNewYorkatanystateofthetide。
Foroceanbars,theoldsystemoftakingthematerialouttoseaanddischargingitstillsurvives,thoughajetofwaterfromforce—pumpsdirectedagainsttheobstructionisalsooftenemployedwithquickresults。Forriverworkwehavediscoveredabettermethod。Allthemudisrunback,sometimesoveramilefromtheriverbank,whereitisusedasafertilizer,bymeansofwirerailwaysstrungfrompoles。Thesewirecablescombineinthemselvesthefunctionsoftrolleywireandsteelrail,andcarrythesuspendedcars,whichemptythemselvesandreturnaroundtheloopforanotherload。Oftentheremovedmaterialentirelyfillssmall,saucer—shapedvalleysorlowplaces,inwhichcaseitcannotwashback。Thisimprovementhasendedthenecessityofbuildingjetties。
\"Thenextimprovementinseatravellingwasthe\'marinespider。\'
Asthenameshows,thisisbuiltontheprincipleofaninsect。
Itiswellknownthatabodycanbecarriedoverthewatermuchfasterthanthroughit。Withthisinmind,buildersatfirstconstructedlightframeworkdecksonlargewater—tightwheelsordrums,havingpaddlesontheircircumferencestoprovideaholdonthewater。Thesetheycausedtorevolvebymeansofmachineryonthedeck,butsoonfoundthattheresistanceofferedtothebarrelwheelsthemselveswastoogreat。Theythereforemadethemmorelikecentipedswithlarge,bell—shapedfeet,connectedwithasuperstructuraldeckbyankle—jointedpipes,throughwhich,whennecessary,apressureofaircanbeforceddownupontheenclosedsurfaceofwater。Ordinarily,however,theygoatgreatspeedwithoutthis,theweightofthewaterdisplacedbythebellfeetbeingasgreatasthatrestinguponthem。Thustheyswingalonglikeapacinghorse,exceptthattherearefourrowsoffeetinsteadoftwo,eachfootbeingtakenoutofthewaterasitisswungforward,thefirstandfourthandsecondandthirdrowsbeingworkedtogether。Although,onaccountoftheirsize,whichcoversseveralacres,theycangoinanywater,theygivethebestresultsonMediterraneansandlakesthatarefreefromoceanrollers,and,underfavourableconditions,makebetterspeedthanthenineteenth—centuryexpresstrains,and,ofcourse,goingstraightasthecrowflies,andwithoutstopping,theyreachadestinationinconsiderablyshortertime。
SomepassengersandexpresspackagesstillcrosstheAtlanticon\'spiders,\'butmostoftheselightcargoesgoinafarpleasanterandmorerapidway。Thedeep—displacementvessels,forheavyfreight,makelittlebetterspeedthanwasmadebythesameclassahundredyearsago。Buttheyarealsorunentirelybyelectricity,largelysuppliedbywind,andbythetideturningtheirmotors,whichbecomedynamoswhileatanchorinanystream。
Theythereforeneednobulkyboilers,engines,sails,orcoal—bunkers,andconsequentlycancarryunprecedentedlylargecargoeswithcomparativelysmallcrews。Theofficersonthebridgeandthemeninthecrow\'snest——thewaytowhichisbyaladderINSIDEthemast,toprotecttheclimberfromtheweather——areaboutallthatisneeded;whiledisablementismadepracticallyimpossible,byhavingfourscrews,eachwithitsownsetofautomaticallylubricatingmotors。
\"Thischange,likeotherlabour—savingappliances,atfirstresultedinlayingoffagoodmanymen,theleastsatisfactorybeingthefirsttogo;buttheincreaseinbusinesswassogreatthattheintelligentmenweresoonreemployedasofficersathigherratesofpayandmoreinterestingworkthanbefore,whiletheyasconsumerswerebenefitedasmuchasanyoneelsebythedecreasedcostofproductionandtransportation。
\"Withaviewtofacilitatinginterchangestillfurther,ourGovernmenthasgraduallycompletedthedoublecoast—linethatNaturegaveusinpart。Thiswasdonebyconnectingislandsseparatedfromshorebynavigablewater,andleavingopeningsforingressandexitbutafewhundredyardswide。Thebreakwatersrequiredtodothiswerebuiltwithcribbingofincorrodiblemetal,affixedtodeeplydrivenmetallicpiles,andfilledwithstonesalongcoastswheretheywerefoundinabundanceorexcess。
This,whileclearingmanyfieldsandimprovingthemforcultivation,providedjusttheneededmaterial;sinceirregularstonesbindtogetherfirmly,and,whilealsoinsoluble,combineconsiderablebulkwithweight。SouthofHatteras,wherestonesarescarce,thesanddredgedfrompartsofthechannelwasfilledintothecrib,thesurfaceofwhichhasaconcavemetalliccover,atroughofstillwaterbeingoftenthebestbarrieragainstthepassageofwaves。Thisdoublecoast—linehasbeenagreatbenefit,andpropelledvesselsofmoderatedraughtcanrangeinsmoothwater,carryingveryfullloads,fromLabradortotheOrinoco。Theexitsare,ofcourse,protectedbyalineofcribbingafewhundredfeettoseaward。
\"TherockshavebeenremovedfromallchannelsaboutNewYorkandothercommercialcentres,whiletheshallowplaceshavebeendredgedtoauniformdepth。Thisdiminishesthedangersofnavigationandconsiderablydecreasesthespeedwithwhichthetidesrushthrough。Wheretheobstructionsconsistedofreefssurroundedbydeepwater,theirremovalwithexplosiveswaseasy,theshatteredfragmentsbeingallowedtosinktothebottomandremaintherebeneaththedangerline。
\"Manyothergreatworkshavealsobeencompleted。ThecanalsatNicaraguahavebeeninoperationmanyyears,ithavingbeenfoundbesttohaveseveralsizesoflocks,andtousethelargeonesonlyforthepassageoflargevessels。TheimprovedErieandChamplainCanalsalsoenableshipsfourhundredfeetlongtoreachNewYorkfromtheGreatLakesviatheHudsonRiver。
\"Forflying,wehaveanaeroplanethatcameinwhenwedevisedasuitablemotorpower。Thisisobtainedfromverylightpaper—cellbatteriesthatcombinesomequalitiesoftheprimaryandsecondarytype,sincetheymustfirstbechargedfromadynamo,afterwhichtheycansupplyfullcurrentsforonehundredhours——enoughtotakethemaroundtheglobe——whilepartlyconsumingtheelementsinthecells。Thepowerisappliedthroughturbinescrews,halfofwhicharecapableofpropellingtheflatdeckinitsinclinedpositionatsufficientspeedtopreventitsfalling。Themovingpartshaveballbearingsandfrictionrollers,lubricationbeingsecuredautomatically,whenrequired,byasupplyofvaselinethatmeltsifanypartbecomeshot。Alltheframingisofthinbutverydurablegalvanizedaluminum,whichhassupersededsteelforeverypurposeinwhichweightisnotanadvantage,asinthepermanentwayonrailways。
Theairships,whoselengthvariesfromfiftytofivehundredfeet,haveruddersforgivingaverticalorahorizontalmotion,andseveralstrengtheningkeelsthatpreventleewaywhenturning。
Theyareentirelyontheprincipleofbirds,maintainingthemselvesmechanically,anddifferingthusfromtheunwieldyballoon。Startingasifonacircularrailway,againstthewind,theyrisetoaconsiderableheight,andthen,shuttingoffthebatteries,coastdowntheaerialslopeataratethatsometimestouchesfivehundredmilesanhour。Whennearthegroundthehelmsmandirectstheprowupward,and,againturningonfullcurrent,rushesuptheslopeataspeedthatfarexceedstheeagle\'s,eachdropoftwomilesservingtotakethemachinetwentyorthirty;though,ifthepilotdoesnotwishtosoar,orifthereisafairwindatagivenheight,hecanremaininthatstratumoftheatmospherebymovinghorizontally。Hecanalsomaintainhiselevationwhenmovingveryslowly,andthoughtheheadwaybeentirelystopped,thedescentisgradualonaccountoftheaeroplane\'sgreatspread,thebatteriesandmotorsbeingsecuredtotheundersideofthedeck。
\"Themotorsaresolightthattheydeveloptwohorsepowerforeverypoundoftheirweight;while,tokeeptheframesthin,thenecessarypowerisobtainedbyterrificspeedofthemovingparts,asthoughasteamengine,toavoidgreatpressureinitscylinders,hadalongstrokeandranatgreatpistonspeed,which,however,isnodisadvantagetotherotarymotionoftheelectricmotor,therebeingnoreciprocatingcranks,etc。,thatmustbestartedandstoppedateachrevolution。
\"Toobviatethenecessityofgearingtoreducethenumberofrevolutionstothosepossibleforalargescrew,thismemberismadeverysmall,andallowedtorevolvethreethousandtimesaminute,sothattherequisitepowerisobtainedwithgreatsimplicityofmechanism,whichfurtherdecreasesfriction。Theshafts,andeventhewiresconnectingthebatterieswiththemotors,aremadelargeandhollow。Thoughtheprimarybatterypureandsimple,astheresultofgreatrecentadvancesinchemistry,seemstobeagaincomingup,thebestaeroplanebatteriesarestillofthecombination—storagetype。Thesehavebeensoperfectedthateightouncesofbatteryyieldonehorsepowerforsixhours,sothattwopoundsofbatterywillsupplyahorsepowerfortwenty—fourhours;asmallfifty—horse—poweraeroplanebeingthereforeabletoflyfourdayswithabatteryweightofbutfourhundredpounds。