\"Byfillingthevestibuleasfullaspossible,\"saidBearwarden,\"andsodisplacingmostofitsair,weshallbeabletoopentheoutsidedooroftenerwithoutdangerofrarefaction。\"
Thethingstheyhaddischargedflewoffwithconsiderablespeedandweresoonoutofsight;butitwasnotnecessaryforthemtomovefast,providedtheymovedatall,for,theresistancebeingnil,theywouldbesuretogobeyondtherangeofvision,providedenoughtimewasallowed,eveniftheCallisto\'sspeedwasnotbeingincreasedbyapergy,inwhichcasearticlesoutsideandnotaffectedwouldbequicklyleftbehind。
Theearth,whichatfirsthadfillednearlyhalftheirsky,wasrapidlygrowingsmaller。Beingalmostbetweenthemselvesandthesun,itlookedlikeacrescentmoon;andwhenitwasonlyabouttwentytimesthesizeofthemoontheycalculatedtheymusthavecomenearlytwohundredthousandmiles。Themoonwasnowonwhatasailorwouldcallthestarboardbow——i。e。,totherightandahead。Beingalittlemorethanthreequartersfull,andonlyaboutfiftythousandmilesoff,itpresentedasplendidsight,brilliantaspolishedsilver,andabouttwenty—fivetimesaslargeastheyhadeverbeforeseenitwiththeunaidedeye。
Itwasjusttenhourssincetheyhadstarted,andatthatmoment9A。M。inNewYork;but,thoughitwasnightthere,theCallistowasbathedinafloodofsunlightsuchasnevershinesonearth。
TheonlynighttheywouldhavewasonthesideoftheCallistoturnedawayfromthesun,unlesstheypassedthroughsomeshadow,whichtheyintendedtoavoidonaccountofthedangerofcollidingwithameteorinthedark。ThemoonandtheCallistoweremovingonconverginglines,thecurveonwhichtheyhadenteredhavingswungthemtothesidenearesttheearth;buttheysawthattheirowntremendousandincreasingspeedwouldcarrytheminfrontofthemooninitsnearlycircularorbit。Wishingtochangethedirectionoftheirflightbythemoon\'sattraction,theyshutoffthepowerdrivingthemfromtheearth,whereupontheCallistoturneditsheavybasetowardsthemoon。Theywerealreadymovingatsuchspeedthattheirmomentumalonewouldcarrythemhundredsofthousandsofmilesintospace,andwerethenalmostabreastoftheearth\'ssatellite,whichwasbutafewthousandmilesaway。Thespectaclewasmagnificent。Astheylookedatitthroughtheirfieldglassesorwiththeunaidedeye,thegreatcracksandcratersshowedwiththeutmostclearness,sweepingpastthemalmostasthelandscapefliespastarailwaytrain。Therewassomethingawe—inspiringinthevastantiquityofthatfurrowedlunarsurface,byfartheoldestthingthatmortaleyecansee,since,whileobservingtheceaselesspoliticalorgeologicalchangesonearth,thefaceofthisdeadsatellite,onaccountoftheabsenceofairandwaterandconsequenterosion,hasremainedunchangedforbygoneages,asitdoubtlesswillformanymore。
TheycloselywatchedtheCallisto\'scourse。Atfirstitdidnotseemtodeflectfromastraightline,andtheystoodreadytoturnontheapergeticforceagain,whenthecarveryslowlybegantoshowtheeffectofthemoon\'snearpull;butnottilltheyhadsofarpasseditthatthedarksidewastowardsthemweretheyheadingstraightforJupiter。Thentheyagainturnedonfullpowerandgotasend—offshoveonthemoonandearthcombined,whichincreasedtheirspeedsorapidlythattheyfelttheycouldsoonshutoffthecurrentaltogetherandsavetheirsupply。
\"Wemustbereadytowatchthesignalsfromthearcticcircle,\"
saidBearwarden。\"Atmidnight,ifthecalculationsarefinished,theresultwillbeflashedbythesearchlight。\"Itwasthentenminutestotwelve,andtheearthwasalreadyoverfourhundredthousandmilesaway。Focusingtheirglassesupontheregionnearthenorthpole,which,beingturnedfromthesun,wastowardsthemandindarkness,theywaited。
\"Inthisblazeofsunlight,\"saidCortlandt,\"Iamafraidwecanseenothing。\"
Fortunately,atthismomenttheCallistoenteredthemoon\'staperingshadow。
\"This,\"saidAyrault,\"isgoodluck。Wecouldofcoursehavegoneintotheshadow;buttochangeourcoursewouldhavedelayedus,andwemighthavelostpartofthechanceofincreasingourspeed。\"
\"Therewillbenodangerfrom,meteorsorsub—satelliteshere,\"
saidBearwarden,\"foranythingrevolvingaboutthemoonatthisdistancewouldbecaughtbytheearth。\"
Thesunhadapparentlysetbehindthemoon,andtheywereeclipsed。Thestarsshonewiththeutmostsplendouragainstthedead—blacksky,andtheearthappearedasalargecrescent,stillconsiderablylargerthanthesatellitetowhichtheywereaccustomed。Exactlyatmidnightafaintphosphorescentlight,likethatofaglow—worm,appearedintheregionofGreenlandontheplanettheyhadleft。Itgraduallyincreaseditsstrengthtillitshonelikealongwhitebeamprojectedfromalighthouse,andinthistheybeheldtheworkofthegreatestsearch—lightevermadebyman,receivingforafewmomentsalltheelectricitygeneratedbytheavailabledynamosatNiagaraandtheBayofFundy,thesteamengines,andothersourcesofpowerinthenorthernhemisphere。Thebeamlastedwithgrowingintensityforoneminute;itthenspelledoutwithclean—cutintervals,accordingtotheCableCode:\"23@no\'6\"。Thesouthernhemispherepumpsarenowraisingandstoringwateratfullblast。
WehavealreadybeguntolowertheArcticOcean。\"
\"Victory！\"shoutedBearwarden,inanecstasyofdelight。\"Nearlyhalfadegreeinsixmonths,withbutonepoleworking。Ifwecanaddatthisrateeachtimetothespeedofstraighteningalreadyacquired,wecanreverseourenginesinfiveyears,andinfivemoretheearthwillbeatrestandright。\"
\"Look！\"saidAyrault,\"theyaresendingsomethingelse。\"Theflashescameinrapidsuccession,reachingfarintospace。Withtheirglassesfixeduponthem,theymadeoutthesesentences:
\"Ourtelescopes,inwhateverpartoftheearthwasturnedtowardsyou,havefollowedyousinceyoustarted,anddidnotlosesightofyoutillyouenteredthemoon\'sshadow。Onyourpresentcourseyouwillbeindarknesstill12。16,whenweshallseeyouagain。\"
Onreceivingthislastearthlymessage,thetravellerssprangtotheirsearchlight,and,usingitsfullpower,telegraphedbackthefollowing:\"Manythankstoyouforgoodnewsaboutearth,andtoSecretaryDeepwatersforlendingusthenavy。Resultofworkmostglorious。Rememberustoeverybody。Shadow\'sedgeapproaching。\"
Thiswasreadbythemeninthegreatobservatories,whoevidentlytelephonedtothearcticSignalLightimmediately,foritflashedback:\"Gotyourmessageperfectly。Wishyougreatestluck。TheT。A。S。Co。hasdeckedtheCallisto\'spedestalwithflowers,andhasorderedatabletsetuponthesitetocommemorateyourcelestialjourney。\"
Atthatmomenttheshadowsweptby,andtheywereinthefullblazeofcloudlessday。Thechangewassogreatthatforamomenttheywereobligedtoclosetheireyes。ThepolishedsidesoftheCallistoshonesobrightlythattheyknewtheywereeasilyseen。ThepowertemporarilydivertedinsendingthemthemessagethenreturnedtotheworkofdrainingtheArcticOcean,which,asthenorthpolewasnowreturningtothesun,wasthethingtodo,andthetravellersresumedtheirstudyoftheheavenlybodies。
CHAPTERII。
SPACEANDMARS。
Neverbeforehadthetravellersobservedthestarsandplanetsundersuchfavourableconditions。Noairorcloudsintervened,andastheCallistodidnotrevolveonitsaxistherewasnonecessityforchangingthedirectionoftheglasses。Afteranhourofthisinterestingwork,however,asitwasalreadylateatthelongitudetheyhadleftonearth,andastheyknewtheyhadmanydaysinspacebeforethem,theypreparedtogotobed。Whenready,theyhadonlytopulldowntheshades;for,asapergywasnotappliedtothem,butonlytotheCallisto,theystilllookeduponthefloorasdown,andclosedtheheavycurtainstohavenightordarkness。TheyfoundthatthesideoftheCallistoturnedconstantlytowardsthesunwasbecomingverywarm,thedouble—toughenedglasswindowsmakingitlikeagreenhouse;buttheyconsoledthemselveswiththethoughtthatthesun\'spoweronthemwashourlybecomingless,andtheyfeltsurethedoublewallsandthickupholsterywouldprotectthemalmostanywherewithinthesolarsystemfromtheintensecoldofspace。
\"Wecouldeasilyhavearranged,\"saidAyrault,fornightanddayonalternatesidesoftheCallistobyhavingstripsofmetalarrangedspirallyontheoutsideasontheendofanarrow。
Thesewouldhavestartedusturningasslowlyaswelike,sincewepassedthroughtheatmosphereatacomparativelylowrateofspeed。\"
\"Iamafraid,\"saidCortlandt,\"themotion,howeverslow,wouldhavemadeusdizzy。Itwouldbeconfusingtoseetheheavensturningaboutus,anditwouldinterferewithusingtheglasses。\"
ThebaseandonesideoftheCallistohadconstantsunshine,whiletheothersideandthedomewereintheblackestnight。
Thisdome,onaccountofitsshape,skywindows,andthecompletenesswithwhichitcouldbeisolated,wasanidealobservatory,andtherewasseldomatimeduringtheirwakinghoursfortherestofthejourneywhenitwasnotoccupiedbyone,two,oralltheobservers。
\"Thereissomethingmarvellous,\"saidCortlandt,\"abouttheconditionofspace。Itsabsolutecoldisappalling,apparentlybecausethereisnothingtoabsorbheat;yetwefindthebaseofthismaterialprojectileuncomfortablywarm,though,shouldweexposeathermometerintheshadeinfront,weknowitwouldshowatemperatureofthreehundredtofourhundreddegreesbelowzero——weretheinstrumentcapableofrecordingit。\"
Artificialdarknesshavingbeenobtained,thetravellersweresoonasleep,Bearwarden\'sdreamsbeingregaledwiththoughtsofhiscompany\'striumph;Ayrault\'s,naturally,withvisionsofSylvia;whileCortlandtfrequentlystartedup,thinkinghehadalreadymadesomegreatastronomicaldiscovery。
About9A。M。,accordingtoseventy—fifthmeridiantime,theexplorersawokefeelinggreatlyrefreshed。Thetankinwhichtheliquefiedoxygenwaskeptautomaticallygaveoffitsgassoevenlythattheairremainednormal,whilethelimecontainedincupsabsorbedthecarbondioxideasfastastheyexhaledit。
Theyhaddarkenedthosewindowsthroughwhichthesunwasactuallypouring,for,onaccountoftheemptinessofthesurroundingetherandconsequentabsenceofdiffusionoflight,nothingbuttheinkyblacknessofspaceandthebrightstarslookedinattherest。Onraisingtheshadestheygotanideaoftheirspeed。Asmallcrescent,smallerthanthefamiliarmoon,accompaniedbyonestilltinier,wasallthatcouldbeseenoftheearthanditssatellite。
\"Wemust,\"saidBearwarden,\"bemovingattherateofnearlyamillionmilesanhour,fromthewaywehavetravelled。\"
\"Wemustbedoingfullyamillion,\"repliedCortlandt,\"forbythistimeweareprettywellinmotion,havinggotatremendousstartwhensonearthemoon,withitandtheearthinline。\"
BysteeringstraightforJupiter,insteadoffortheplaceitwouldoccupytendayslater,theyknewtheywouldswingpast,forthegiantplanet,beinginrapidmotion,wouldadvance;buttheydidnotobjecttothis,sinceitwouldgivethemachancetoexaminetheirnewworldincasetheywishedtodosobeforealighting;while,iftheypreferredtolandatonce,theycouldeasilychangetheircoursebymeansofthemoons,thefourth,fromwhichtheircarwasnamed,beingtheonethattheyknewwouldbeofmostuse。Theirtremendousspeedshowedthemtheyshouldhavetimeforexplorationontheirarrival,andthattheywouldreachtheirdestinationsoonerthantheyhadexpected。Theapergeticforcebeingapplied,aswehaveseen,onlytotheCallisto,justaspowerinstartingisexertedonacarriageorrailwaycarandonlythroughittothepassengers,Ayraultandhiscompanionshadnounusualsensationexceptlossofweight,for,whentheyweresofarfromtheearth,itsattractionwasveryslight,andnootherplanetwasnearenoughtotakeitsplace。Afterbreakfast,wishingtoreachthedome,andrealizingthatitwouldbeunnecessarytoclimb,eachinturngaveaslightspringandwasobligedtoputuphishandstoavoidstrikingtheroof。Inthecoolquietofthedarkdomeitwasdifficulttobelievethatonlytwentyfeetawaythesunwasshiningwithsuchintensityuponthemetalbaseastomakeittoohotontheinsidetotouchwithoutgloves。
ThefirstthingthatattractedtheirattentionwasthesizeandbrillianceofMars。Althoughthisredplanetwasoverfortymillionmilesfromtheearthwhentheystarted,theycalculatedthatitwaslessthanthirtymillionmilesfromthemnow,orfivemillionsnearerthanithadeverbeentothembefore。Thisreductionindistance,andtheclearnessofthevoidthroughwhichtheysawit,madeitasplendidsight,itsdiskshowingclearly。Fromhourtohouritssizeandbrightnessincreased,tilltowardseveningitlookedlikeasmall,fullmoon,thesunshiningsquarelyuponit。Theycalculatedthatonthecoursetheyweremovingtheyshouldpassaboutninehundredthousandmilestotherightorbehindit,sinceitwasmovingtowardstheirleft。TheywereinterestedtoseewhateffectthemassofMarswouldhaveontheCallisto,andsawhereachanceofstillfurtherincreasingtheirspeed。Notwithstandingitstremendousrate,theyexpectedtoseetheCallistoswervefromitsstraightlineandmovetowardsMars,whoseorbitalspeedofninehundredmilesaminutetheythoughtwouldtakeitoutoftheCallisto\'sway,sothatnoactualcollisionwouldoccureveniftheirair—shipwerelefttoherowndevices。
Towardseveningtheynoticedthroughtheirglassesthatseveralapparentlyislandpeaksinthesouthernhemisphere,whichwasturnedtowardsthem,becamewhite,fromwhichtheyconcludedthatasnow—stormwasinprogress。Thesouthpolarregionwasalsomarkedlyglaciated,thoughtheicecapwasnotasextensiveaseitherofthoseatthepolesoftheearth。
\"AstheMartianwintersmustbefullyassevereasours,\"saidCortlandt,\"onaccountoftheirlength,theplanet\'sdistancefromthesun,andthetwenty—sevenandahalfdegreesinclinationofitsaxis,wecanaccountforthesmallnessofitsice—capsonlybythefactthatitsoceanscoverbutonefourthofitssurfaceinsteadofthreequarters,asontheearth,andthereisconsequentlyasmallerevaporationandrainandsnow—fall。\"
Theyweretoomuchinterestedtothinkofsleepingthatnight,andso,afterdiningcomfortablyreturnedtotheirobservatory。
WhenwithinfourmillionmilesofMarstheCallistobegantoswerveperceptibly,itscurve,aswhennearthemoonbeginningwithaspiral。Theyswungonunconcernedly,however,knowingtheycouldchecktheirapproachatanytime。SoonMarsappearedtohaveadiametertentimesasgreatasthatofthemoon,andpromisedshortlytooccupyalmostonesideoftheirsky。
\"Wemustbeonthelookoutforthesatellites,\"saidCortlandt;
\"acollisionwitheitherwouldbeworsethanawreckonadesertisland。\"
Theythereforeturnedtheirglassesinthedirectionofthesatellites。
\"UntilProf。Hall,atWashington,discoveredthetwosatellitesin1877,\"hecontinued,\"Marswassupposedtobewithoutmoons。
Theouterone,Deimos,isbutsixmilesindiameter,andrevolvesaboutitsprimaryinthirtyhoursandeighteenminutes,atadistanceoffourteenthousandsixhundredmiles。AsittakesbutlittlelongertocompletearevolutionthanMarsdoestorotateonitsaxis,itremainsintheMartialskyonehundredandthirty—twohoursbetweenrisingandsetting,passingthroughallthephasesfromnewmoontofullandbackagainfourtimes;thatis,itswingsfourtimesaroundMarsbeforegoingbelowthehorizon。Itisoneofthesmallestbodiesdiscoveredwithatelescope。Theinnerone,Phobos,isconsiderablylarger,havingadiameterofabouttwentymiles。Itisbuttwenty—sevenhundredmilesfromMars\'ssurface,andcompletesitsrevolutioninsevenhoursandthirty—eightminutes,whichisshorterthananyotherknownperiod,Jupiter\'snearestmoonbeingthenext,withelevenhoursandfifty—nineminutes。ItthusrevolvesinlessthanathirdofthetimeMarstakestorotate,andmustconsequentlyriseinthewestandsetintheeast,asitiscontinuallyrunningaheadofthesurfaceoftheplanet,thoughthesunandalltheotherstarsriseandsetonMarsinthesamewayasontheearth。\"
WhenaboutfifteenthousandmilesfromMars,theysightedDeimosdirectlyahead,andsawthattheyshouldpassonitsleft——i。e。,behind——foritwasmovingacrossthem。Thesunpoureddirectlyuponit,makingitappearfullandshowingallitsfeatures。
Thereweresmallunevennessesonthesurface,apparentlyseventyorahundredfeethigh,whichwerethenearestapproachtomountains,andtheyraninridgesorchains。Therewerealsounmistakablesignsofvolcanicaction,thecratersbeinglargecomparedwiththesizeoftheplanet,butshallow。Theysawnosignsofwater,andtheblacknessoftheshadowsconvincedthemtherewasnoair。TheysecuredtwoinstantaneousphotographsofthelittlesatelliteastheCallistosweptby,andresumedtheirinspectionofMars。Theynoticedredandbrownishpatchesonthepeaksthathadthatmorningturnedwhite,fromwhichtheyconcludedthattheshowhadbeguntomeltunderthewarmspringsun。Thisstrengthenedthebelieftheyhadalreadyformed,thatonaccountofitstwenty—sevenandahalfdegreesinclinationthechangesintemperatureonMarsmustbegreatandsudden。Sointerestedweretheywiththis,thattheydidnotatfirstseealargeandbrightbodymovingrapidlyonacoursethatconvergedwiththeirs。
\"Wemustbereadytorepelboarders,\"saidBearwarden,observingitforthefirsttimeandfixinghisglassuponit。\"ThatmustbePhobos。\"
NottenmilesofftheybeheldMars\'sinnermoon,andthoughtheirownspeedcausedthemtoovertakeandrushbyitlikeawhirlwind,thesatellite\'srapidmotioninitsorbit,inacoursetemporarilyalmostparallelwiththeirs,servedtogivethemachancethebettertoexamineit。HerethemountainrangeswereconsiderablymoreconspicuousthanonDeimos,andtherewerebouldersandloosestonesupontheirslopes,whichlookedasiftheremightatsometimehavebeenfrostandwateronitssurface;butitwasalldrynow,neitherwasthereanyair。Theevidencesofvolcanicactionwerealsoplainlyvisible,whileanoticeableflatteningatthepolesshowedthatthelittlebodyhadoncerotatedrapidlyonitsaxis,thoughwhetheritdidsostilltheyhadnottimetoascertain。Whenabreastofittheywerelessthantwomilesdistant,andtheysecuredseveralinstantaneousimpressions,whichtheyputasidetodeveloplater。
AstheradiusofPhobos\'scirclewasfarshorterthanthatoftheparaboliccurvetheyweremaking,itbegantodrawaway,andwasrapidlyleftbehind。ApplyingthefullapergeticforcetoMarsandthelargermoon,theyshotawaylikeanarrow,havinghadtheirspeedincreasedbytheplanet\'sattractionwhileapproachingit,andsubsequentlybyrepulsion。
\"Eitherofthose,\"saidBearwarden,lookingbackatthelittlesatellites,\"wouldbeaniceyachtforamantoexplorespaceon。
Hewouldalso,ofcourse,needasuntowarmhim,ifhewishedtogobeyondthissystem,butthatwouldnothavetobealargeaffair——infact,itmightbesmallerthantheplanet,andcouldrevolveaboutitlikeamoon。\"
\"Thoughasunofthatsize,\"repliedCortlandt,\"mightretainitsheatforthetimeyouwishedtouseit,theplanetpartwouldbenothinglikeascomfortableaswhatwehavehere,foritwouldbeverydifficulttogetenoughair—pressuretobreatheonsosmallabody,since,withitsslightgravitation—pull,tosecurefifteenpoundstothesquareinch,oranythinglikeit,theatmospherewouldhavetoextendthousandsofmilesintospace,sothatonacloudydayyouwouldbeindarkness。Itwouldbebetter,therefore,tohavesuchasunasyoudescribeandaccompanyitinayachtorprivatecarlikethis,wellstockedwithoxygenandprovisions。Whenpassingthroughmeteoricswarmsormassesofsolidmatter,collisionwithwhichisthemostseriousriskwerun,thecarcouldfollowbehinditssuninsteadofrevolvingaroundit,andbekeptfromfallingintoitbypartiallyreversingtheattraction。Asthegravitationofsosmallasunwouldbeslight,counteractingitforevenaconsiderabletimewouldtakebutlittlefromthebatteries。\"
\"Thereareknowntobeseveralunclaimedmasses,\"addedAyrault,\"withdiametersofafewhundredyards,revolvingabouttheearthinsidetheorbitofthemoon。Ifinsomewaytwoofthesecouldbebroughtintosufficientlyviolentcollision,theywouldbecomeluminousandanswerverywell;theincreaseinbulkasaresultoftheconsolidation,andthesubsequentheat,aboutservingtobringthemtotherequiredsize。Wheneverthissunshowedspotsandindicationsofcooling,itcouldbemadetocollidewiththesolidheadofsomecomet,orsmallasteroid,tillitstemperaturewasagainright;whileif,asaresultoftheseaccretions,itbecameunwieldy,itcouldbecausedtorotatewithsufficientrapidityonitsaxistosplit,andweshouldhavetwosunsinsteadofone。\"
\"Bravo！\"saidBearwarden。\"Thereisnolimittowhatcanbedone。Theideaofourpresenttripwouldhaveseemedmorechimericaltopeopleahundredyearsagothanthisnewschemeappearsnow。\"
Thustheysatandtalked,orstudiedmapsandstar—charts,orthestarsthemselves,whilethehoursquicklypassedandtheyshotthroughspace。Theyhadnowastraightstretchofoverthreehundredmillionmiles,andhadtocrosstheorbitsofinnumerableasteroidsontheway。Theapparentsizeofthesunhadbythistimeconsiderablydecreased,andtheinterioroftheCallistowasnolongeruncomfortablywarm。Theydividedthedayintotwenty—fourhoursfromforceofhabit,anddrewtheshadestightlyduringwhattheyconsiderednight,whileBearwardendistinguishedhimselfasacook。
CHAPTERIII。
HEAVENLYBODIES。
Thefollowingday,whileintheirobservatory,theysawsomethingnotmanymilesahead。Theywatcheditforhours,andinfactallday,butnotwithstandingtheirtremendousspeedtheycamebutlittlenearer。
\"Theysayasternchaseisalongone,\"saidBearwarden;butthatbeatsanythingIhaveeverseen。\"
Afterawhile,however,theyfoundtheyWEREnearer,thetimetakenhavingbeeninpartduetothedeceptivedistance,whichwasgreaterthantheysupposed。
\"Acomet！\"exclaimedCortlandtexcitedly。\"Weshallreallybeabletoexamineitnear。\"
\"It\'sgoinginourdirection,\"saidAyrault,\"andatalmostexactlyourspeed。\"
Whilethesunshonefulluponittheybroughttheircameraintoplay,andagainsucceededinphotographingaheavenlybodyatcloserange。Thenucleusorheadwasofcourseturnedtowardsthesun;whilethetail,whichtheycouldseefaintly,precededit,asthecometwasrecedingtowardsthecoldanddarkdepthsofspace。Theheadwasonlyafewmilesindiameter,foritwasasmallcomet,andwascomposedofgrainsandmassesofstoneandmeteoriciron。Manyofthegrainswerenolargerthanpeasormustard—seeds;nomasswasmorethanfourfeetindiameter,andallofthemhadveryirregularshapes。Thespacebetweentheparticleswasneverlessthanonehundredtimestheirmasses。
\"Wecanmoveaboutwithinit,\"saidAyrault,astheCallistoenteredtheaggregationofparticles,andmovedslowlyforwardamongthem。
Thewindowsinthedome,beingmadeoftoughenedglass,setsomewhatslantinglysoastodeflectanythingtouchingthem,andhaving,moreover,thepressureoftheinsideairtosustainthem,werefairlysafe,whilethewindowsinthesidesandbasewerebutlittleexposed。Wheneveralargemassseemeddangerouslyneartheglass,theyappliedanapergeticshocktoitandsentitkitingamongitsfellows。AtthesetimestheCallistorecoiledslightlyalso,theresultingmotionineitherbeingininverseratiotoitsweight。Therewasconstantandincessantmovementamongtheindividualfragments,butitwasnotrotary。Nothingseemedtoberevolvingaboutanythingelse;allweremoving,apparentlyswingingbackandforth,butnocollisionstookplace。
Whentheseparateparticlesgotmorethanacertaindistanceaparttheyreapproachedoneanother,butwhenseeminglywithinaboutonehundreddiametersofeachothertheyswungoffinsomeotherdirection。Themotionwaslikethatofinnumerableharp—strings,whichmayapproachbutneverstrikeoneanother。
AfteratimetheCallistoseemedtobecomeendowedwiththesamepropertythatthefragmentspossessed;foritandtheyrepelledoneanother,onanearapproach,afterwhichnothingcameverynear。
Muchofthematerialwaslikeslagfromafurnace,havingevidentlybeenpartlyfused。Whetherthisheatwastheresultofcollisionorofitsnearapproachtothesunatperihelion,theycouldnottell,thoughthelatterexplanationseemedmostsimpleandprobable。Whenataboutthecentreofthenucleustheywereinsemi—darkness——nottwilight,foranyraythatsucceededinpenetratingwasdazzlinglybrilliant,andtheshadows,theirownincluded,wereinkyblack。Astheyapproachedthefarthersideandthesunlightdecreased,theyfoundthatadiffusedluminositypervadedeverything。Itwassufficientlybrighttoenablethemtoseethedarksideofthemeteoricmasses,and,onemergingfromthenucleusintotaldarkness,theyfoundtheshadowstretchingthousandsofmilesbeforethemintospace。
\"Inowunderstand,\"saidBearwarden,\"whystarsofthesixthandseventhmagnitudecanbeseenthroughthousandsofmilesofacomet\'stail。Itissimplybecausethereisnothinginit。ThereasonANYstarsareobscuredisbecausethelightinthetail,howeverfaint,isbrighterthanthey,andthatlightisallthatthecaudalappendageconsistsof,thoughwhatproducesitI
confessIamunabletoexplain。Ialsoseewhythetailalwaysstretchesawayfromthesun,becausenearbyitisoverwhelmedbythemorepowerfullight;infact,Isuspectitisprincipallyinthecomet\'sshadowthatthetailisvisible。Itisstrangethatnooneeverthoughtofthatbefore,orthatanyonefearedtheearth\'spassingthroughthetailofacomet。Itisobvioustomenowthatiftherewereanymaterialsubstance,anygas,howeverrarefied,inthishairlike[1]accompaniment,itwouldimmediatelyfalltothecomparativelyheavyhead,andsurroundthatasacentre。\"
[1]Cometmeansliterallyahair。
\"How,then,\"askedCortlandt,\"doyouaccountforthespacesbetweenthosestones？Howeverslightgravitationmightbebetweensomeofthegrains,ifitexistedatall,orwasunopposedbysomeotherforce,withsufficienttime——andtheyhaveeternity——everycometwouldcometogetherlikeaplanetintoonesolidmass。Perhapssomesimilarforcemaintainsgasesinthedistendedtail,thoughIknowofnosuch,orevenanyanalogousmanifestationonearth。Ifthelawonwhichwehavebeenbroughtup,that\'everyatomintheuniverseattractseveryotheratom,\'werewithoutexceptionsormodifications,thatcometcouldnotcontinuetoexistinitspresentform。Untilwegetsomeadditionalillustration,however,weshallbeshortofdatawithwhichtoformulateanyiconoclastichypothesis。Thesourceofthelight,Imustadmit,alsopuzzlesmegreatly。Thereiscertainlynoheattowhichwecanattributeit。\"
Havinggonebeyondthefragments,theyappliedastrongrepulsionchargetothecomet,creatingtherebyaperfectwhirlpoolamongitsparticles,andquicklyleftit。Halfanhourlatertheyagainshutoffthecurrent,astheCallisto\'sspeedwassufficient。
Forsometimetheyhadbeeninthebeltofasteroids,butasyettheyhadseennonenear。Themorningfollowingtheirexperiencewiththecomet,however,theywenttotheirobservatoryafterbreakfastasusual,and,onpointingtheirglassesforward,espiedacomparativelylargebodybeforethem,alittletotheirright。
\"ThatmustbePallas,\"saidCortlandt,scrutinizingitclosely。
\"ItwasdiscoveredbyOlbers,in1802,andwasthesecondasteroidfound,Cereshavingbeenthefirst,in1801。Ithasadiameterofaboutthreehundredmiles,beingoneofthelargestofthesesmallplanets。Themostwonderfulthingaboutitistheinclinationofitsorbit——thirty—fivedegrees——totheplaneoftheecliptic;whichmeansthatateachrevolutioninitsorbit,itswingsthatmuchaboveandbelowtheimaginaryplanecuttingthesunatitsequator,fromwhichtheearthandotherlargerplanetsvarybutlittle。Thisnodoubtisduetothenearapproachanddisturbingattractionofsomelargecomet,orelseitwasflungaboveorbelowtheordinaryplaneinthecatastrophethatwethinkbefellthelargeplanetthatdoubtlessformerlyexistedwherewenowfindthisswarm。Youcanseethatitspathmakesaconsiderableangletotheplaneoftheecliptic,andthatitisnowaboutcrossingtheline。\"
Itsoonpresentedthephaseofahalfmoon,butthewavinessofthestraightline,asinthecaseofVenusandMercury,showedthatthesizeofthemountainsmustbetremendouscomparedwiththemassofthebody,someofthembeingobviouslyfifteenmileshigh。Theintenseblacknessoftheshadows,asonthemoon,convincedthemtherewasnotraceofatmosphere。
\"Therebeingnoair,\"saidCortlandt,\"itissafetoassumethereisnowater,whichhelpstoaccountforthegreatinequalitiesonthebody\'ssurface,sincethemountainswillseemhigherwhensurroundedbydryocean—bottomthantheywouldifwatercamehalfwayuptheirsides。Undoubtedly,however,themaincauseoftheirheightistheslighteffectofgravitationonanasteroid,andthefactthattheshrinkingoftheinterior,andconsequentfoldingofthecrustinridges,mayhavecontinuedforatimeaftertherewasnolongerwateronthesurfacetocutthemdown。
\"Thetemperatureandconditionofabody,\"continuedCortlandt,\"seemtodependentirelyonitssize。Inthesunwehaveanincandescent,gaseousstar,thoughitsspotsandthecolourofitsraysshowthatitisbecomingaged,or,tobemoreaccurate,advancedinitsevolutionarydevelopment。Thencomesagreatjump,forJupiterhasbutaboutonefourteen—hundredthofthemassofthesun,andweexpecttofindonitafirmcrust,andthattheplanetitselfisataboutthefourthorfifthperiodofdevelopment,describedbyMosesasdays。Saturnisdoubtlesssomewhatmoreadvanced。Theearthweknowhasbeenhabitablemanyhundredsofthousandsormillionsofyears,thoughthreefourthsofitssurfaceisstillcoveredbywater。InMarsweseeafurtherstep,threefourthsofitssurfacebeingland。InMercury,couldwestudyitbetter,orinthelargersatellitesofJupiterorSaturn,wemightfindastepping—stonefromMarstothemoon,perhapswithnowater,butstillhavingair,andbeinghabitableinallotherrespects。Inourownsatelliteweseeaworldthathasdied,thoughitsdeathfromanastronomicalpointofviewiscomparativelyrecent,whilethislittlePallashasbeendeadlonger,beingprobablychilledthroughandthrough。
FromthisIconcludethatallbodiesinthesolarsystemhadonegenesis,andwerepartofthesamenebulousmass。Butthisdoesnotincludetheothersystemsandnebulae;for,comparedwiththem,oursun,aswehaveseen,isitselfadvancedandsmallbesidesuchstarsasSiriushavingdiametersoftwelvemillionmiles。\"
AstheyleftPallasbetweenthemselvesandthesun,itbecameacrescentandfinallydisappeared。
Twodayslatertheysightedanotherasteroidexactlyahead。Theyexamineditclosely,andconcludeditmustbeHilda,putdownintheastronomiesasNo。153,andhavingalmostthegreatestmeandistanceofanyofthesesmallbodiesfromthesun。
Whentheyweresonearthatthediskwasplainlyvisibletotheunaidedeye,HildapassedbetweenthemandJupiter,eclipsingit。
Totheirsurprise,thelightwasnotinstantlyshutoff,aswhenthemoonoccultsastar,buttherewasevidentrefraction。
\"ByGeorge！\"saidBearwarden,\"hereisanasteroidthatHASanatmosphere。\"