CHAPTERI。
THEDAWNOFAERONAUTICS。
"Hethatwouldlearntoflymustbebroughtuptotheconstantpracticeofitfromhisyouth，tryingfirstonlytousehiswingsasatamegoosewilldo，sobydegreeslearningtorisehighertillheattainuntoskillandconfidence。"
SowroteWilkins，BishopofChester，whowasreckonedamanofgeniusandlearninginthedaysoftheCommonwealth。ButsosoonaswecometoinquireintothematterwefindthatthisgoodBishopwasborrowingfromtheideasofotherswhohadgonebeforehim;and，lookbackasfaraswewill，mankindisdiscoveredtohaveentertainedpersistentandoftenplausibleideasofhumanflight。Andthoseideashadinsomesortofway，forgoodorill，takenpracticalshape。Thus，aslongagoasthedayswhenXenophonwasleadingbackhiswarriorstotheshoresoftheBlackSea，anderetheGaulshadfirstburnedRome，therewasaphilosopher，Archytas，whoinventedapigeonwhichcouldfly，partlybymeansofmechanism，andpartlyalso，itissaid，byaidofanauraorspirit。Andherearisesaquestion。Wasthisauraagas，ordidmenuseitasspiritualistsdotoday，asmerelyawordtoconjurewith？
Fourcenturieslater，inthedaysofNero，therewasamaninRomewhoflewsowellandhighastolosehislifethereby。
Here，atanyrate，wasanhonestman，orthestorywouldnothaveendedthus;butoftherest——andtherearemanywhoinearlyagesaspiredtotheattainmentofflight——wehavenomorereasontocredittheirclaimsthanthoseofcharlatanswhoflourishineveryage。
Inmedievaltimesweareseriouslytoldbyasaintlywriter（St。Remigius）offolkswhocreatedcloudswhichrosetoheavenbymeansof"anearthenpotinwhichalittleimphadbeenenclosed。"Weneednomore。Thatwasanageofflyingsaints，asalsoofflyingdragons。Flyinginthosedaysofyoremayhavebeenrealenoughtothemultitude，butitwasatbestdelusion。InthegoodoldtimesitdidnotneedthegeniusofaMaskelynetodoa"levitation"trick。Wecanpicturethesceneata"flyingseance。"Ontheonesidethedecidedlyprofessionalshowmanpossessedofsufficientlowcunning;ontheothertheignorantandhighlysuperstitiousaudience，eagertohearorseesomenewthing——thesameaudiencethat，deceivedbyasimpletrickofschoolboyscience，wouldlistentosupernaturalvoicesintheirgroves，ororacularutterancesintheirtemples，orwatchtheurnsofBacchusfillthemselveswithwine。Surelyfortheireyesitwouldneednomorethanthesimplestphantasmagoria，ormaybeonlyalittleblackthread，tomakeapigeonriseandfly。
Itisinterestingtonote，however，thatinthecaselastcitedthereisunquestionablyanallusiontosomecrudeformoffirework，andwhatmorelikelyorbettercalculatedtoimpresstheignorant！Ourfireworkmakersstillmanufacturea"littleDevil。"Pyrotechnicisasoldashistoryitself;wehaveanexcellentdescriptionofarocketinadocumentatleastasancientastheninthcentury。AndthataspeciesofpyrotechnywasresortedtobythosewhosoughttoimitateflightwehaveproofinthefollowingrecipeforaflyingbodygivenbyaDoctor，ekeaFriar，inParisinthedaysofourKingJohn:——
"Takeonepoundofsulphur，twopoundsofwillowcarbon，sixpoundsofrocksaltgroundveryfineinamarblemortar。
Place，whenyouplease，inacoveringmadeofflyingpapyrustoproducethunder。Thecoveringinordertoascendandfloatawayshouldbelong，graceful，wellfilledwiththisfinepowder;buttoproducethunderthecoveringshouldbeshort，thick，andhalffull。"
Nordoesthisrecipestandalone。Takeanothersample，ofwhichchapterandversearetobefoundintheMSS。ofaJesuit，GaspardSchott，ofPalermoandRome，bornthreehundredyearsago:——
"Theshellsofhen—eggs，ifproperlyfilledandwellsecuredagainstthepenetrationoftheair，andexposedtosolarrays，willascendtotheskiesandsometimessufferanaturalchange。
Andiftheeggsofthelargerdescriptionofswans，orleatherballsstitchedwithfinethongs，befilledwithnitre，thepurestsulphurquicksilver，orkindredmaterialswhichrarifybytheircaloricenergy，andiftheyexternallyresemblepigeons，theywilleasilybemistakenforflyinganimals。"
Thusitwouldseemthat，huntingbackinhistory，therewerethreemainideasonwhichwould—beaeronautsofoldexercisedtheiringenuity。Therewasthelast—mentionedmethod，which，bytheway，JulesVernepartlyreliesonwhenhetakeshisheroestothemoon，andwhichinitshighestpracticaldevelopmentmaybeseenannuallyonthenightof"Brock’sBenefit"attheCrystalPalace。Thereis，again，the"tamegoose"method，towhichwemustreturnpresently;and，lastly，thereisathirdmethod，towhich，asalsotothebrilliantgeniuswhoconceivedit，wemustwithoutfurtherdelaybeintroduced。Thismaybecalledthemethodof"ahollowglobe。"
RogerBacon，Melchisedeck—fashion，cameintoexistenceatIlchesterin1214ofparentagethatishardtotrace。Hewas，however，abornphilosopher，andpossessedofintellectandpenetrationthatplacedhimincalculablyaheadofhisgeneration。Amanofmarvellousinsightandresearch，hegrasped，andasfaraspossiblecarriedout，ideaswhichdawnedonothermenonlyaftercenturies。Thus，manyofhisutteranceshavebeenprophetic。Itisprobablethatamonghischemicaldiscoverieshere—inventedgunpowder。Itiscertainthathedivinedthepropertiesofalens，anddivingdeepintoexperimentalandmechanicalsciences，actuallyforesawthetimewhen，inhisownwords，"menwouldconstructenginestotraverselandandwaterwithgreatspeedandcarrywiththempersonsandmerchandise。"ClearlyinhisdreamsBaconsawtheAtlanticnotmerelyexplored，butonitsbosomtheWhiteStarlinersbreakingrecords，contemptuousofitsangriestseas。Hesaw，too，afutureDumontcirclingintheair，andnotonlyinadeadcalm，butholdinghisownwiththefeatheredrace。Hetellshisdreamthus:"Theremaybemadesomeflyinginstrumentsothatamansittinginthemiddleoftheinstrumentandturningsomemechanismmayputinmotionsomeartificialwingswhichmaybeattheairlikeabirdflying。"
Buthelivedtoolongbeforehistime。Hisruinlaynotonlyinhissuperiorgenius，butalsoinhisfearlessoutspokenness。
HepresentlyfellunderthebanoftheChurch，throughwhichhelostalikehislibertyandthemeansofpursuinginvestigation。
Haditbeenotherwisewemayfairlybelievethatthe"admirableDoctor，"ashewascalled，wouldhavebeenthefirsttoshowmankindhowtonavigatetheair。Hisideasareperfectlyeasytograsp。Heconceivedthattheairwasatruefluid，andassuchmusthaveanupperlimit，anditwouldbeonthisuppersurface，hesupposed，asonthebosomoftheocean，thatmanwouldsailhisair—ship。Afine，boldguesstruly。Hewouldwatchthecirruscloudssailinggrandlytenmilesabovehimonsomestreamthatneverapproachednearer。Upthere，inhisimagination，wouldbetossingthewavesofouroceanofair。
Waitforsomelittlebettercylindersofoxygenandanimprovedfoot—warmer，andafutureCoxwellwillgoaloftandsee;butastoanuppersea，itistrulythere，andwemayvisitandviewitssun—littossingbillowsstretchingouttoalimitlesshorizonatsuchtimesasthenetherworldisshroudedindensestgloom。Bacon’smethodofreachingsuchanupperseaashepostulatedwas，aswehavesaid，byahollowglobe。
"Themachinemustbealargehollowglobe，ofcopperorothersuitablemetal，wroughtextremelythinsoastohaveitaslightaspossible，"and"itmustbefilledwithetherealairorliquidfire。"Thiswaswritteninthethirteenthcentury，anditisscarcelyedifyingtofindfourhundredyearsafterthistheJesuitFatherLana，whocontrivedtomakehisnameliveinhistoryasatheoriserinaeronautics，arrogatingtohimselftheboldconceptionoftheEnglishFriar，withcertainunfortunatedifferences，however，whichinfairnesswemusthereclearlypointout。Lanaproclaimedhisspeculationsstandingonagiant’sshoulders。Torricelli，withhisclosedbenttube，hadjustshowntheworldhowheavilytheairliesaboveus。Itthenrequiredlittlemathematicalskilltocalculatewhatwouldbetheliftingpowerofanyvesselvoidofairontheearth’ssurface。ThusLanaproposedtheconstructionofanairshipwhichpossiblybecauseofitspicturesquesnesshaswonhimnotoriety。Butitwasafraud。Wehavebuttoconceiveadaintyboatinwhichtheaeronautwouldsitateasehandlingalittlerudderandasimplesail。These，thoughaschoolboywouldhaveknownbetter，hethoughtwouldguidehisvesselwhenintheair。
SomuchhasbeenclaimedforFatherLanaandhismathematicalandotherattainmentsthatitseemsonlyrighttoinsistontheweaknessofhisreasoning。Anairshipsimplydriftingwiththewindisincapableofalteringitscourseintheslightestdegreebyeithersailorrudder。Itissimplylikealogbornealonginatorrent;buttocomparesuchalogproperlywiththeairshipwemustconceiveitWHOLLYsubmergedinthewaterandhavingnosailorotherappendageprojectingintotheair，whichwould，ofcourse，introduceotherconditions。If，however，amanweretositastrideofthelogandbegintopropelitsothatittravelseitherfasterorslowerthanthestream，theninthatcase，eitherbypaddleorrudder，thelogcouldbeguided，andthesamemightbesaidofLana’sairboatifonlyhehadthoughtofsomeadequatepaddle，fan，orotherpropeller。Buthedidnot。Onefurtherexplanatorysentencemayherebeneeded;forwehearofballoonswhicharecapableofbeingguidedtoasmallextentbysailandrudder。Inthesecases，however，therudderisaguideropetrailingonearthorsea，sointroducingafreshelementandfreshconditionswhichareeasytoexplain。
Supposeafreeballoondriftingdownthewindtohaveasailsuddenlyhoistedononeside，whathappens？Theballoonwillsimplyswingtillthissailisinfront，andthuscontinueitsstraightforwardcourse。Suppose，however，thatassoonasthesidesailishoistedatrailropeisalsodroppedaftfromasparintherigging。Thetendencyofthesailtoflyroundinfrontisnowcheckedbythedraggingrope，anditisconstrainedtoremainslantingatanangleononeside;atthesametimetherateoftheballoonisreducedbythedraggingrope，sothatittravelsslowerthanthewind，which，nowactingonitsslantsail，impartsacertainsidelongmotionmuchasitdoesinthecaseofasailingboat。
Lanahavinginimaginationbuilthisship，proceedstomakeitfloatupintospace，forwhichpurposeheproposesfourthincopperglobesexhaustedofair。Hadthislastbeenhisownideawemighthavepardonedhim。Wehave，however，pointedoutthatitwasnot，andwemustfurtherpointoutthatincopyinghisgreatpredecessorhefailstoseethathewouldloseenormousadvantagebyusingfourglobesinsteadofone。But，beyondall，hefailedtoseewhatthemastergeniusofBaconsawclearly——thathisthinglobeswhenexhaustedmustinfalliblycollapsebyvirtueofthatverypressureoftheairwhichhesoughttomakeuseof。
ItcannotbetoostronglyinsistedonthatifthetoomuchbelaudedspeculationsofLanahaveanyvalueatallitisthattheythrowintostrongercontrastthewonderfulinsightofthephilosopherwhosolongprecededhim。BysheergeniusBaconhadforeseenthattheemptiedglobemustbefilledwithSOMETHING，andforthissomethinghesuggests"etherealair"or"liquidfire，"neitherofwhich，wecontend，wereemptyterms。WithBacon’sknowledgeofexperimentalchemistryitisaquestion，andamostinterestingone，whetherhehadnotinhismindthosetwoactualprinciplesrespectivelyofgasandairrarefiedbyheatonwhichwelaunchourballoonsintospaceto—day。
Earlyprogressinanyartorscienceiscommonlyintermittent。
Itwassointhestoryofaeronautics。Advancewaslikethatoftheincomingtide，throwinganoccasionalwavefarinfrontofitsrisingflood。ItwasaphenomenalwavethatboreRogerBaconandlefthismarkonthesandwherenoneotherapproachedforcenturies。Inthosecenturiesmenwereeithertoopriest—riddentolendaneartoScience，or，likechildren，followedonlytheWill—o’—the—Wispfloatingabovethequagmirewhichheldthemfast。Theyranafterthestonethatwastoturnalltogold，ortheelixirthatshouldconquerdeath，orthesignsintheheavensthatshouldforetelltheirdestinies;
andthetaintofthismaybetracedevenwhenthedarkperiodthatfollowedwasclearingaway。FourhundredyearsafterRoger’sdeath，hisillustriousnamesake，FrancisBacon，wasformulatinghisInductivePhilosophy，andwithcompletecock—surenesswasteachingmankindallabouteverything。Letuslookatsomeofhisutteranceswhichmayhelptothrowlightonthewayheregardedtheproblemwearedealingwith。
"Itisreported，"FrancisBaconwrites，"thattheLeucaciansinancienttimedidusetoprecipitateamanfromahighcliffeintothesea;tyingabouthim，withstrings，atsomedistance，manygreatfowles;andfixinguntohisbodydiversfeathers，spread，tobreakethefall。Certainlymanybirdsofgoodwing（asKitesandthelike）wouldbeareupagoodweightastheyflie。Andspreadingoffeathers，thinandclose，andingreatbreadth，willlikewisebeareupagreatweight，beingevenlaidwithouttiltinguponthesides。Thefurtherextensionofthisexperimentofflyingmaybethoughtupon。"
Tosaytheleast，thisishardlymechanical。ButletusnextfollowthephilosopherintothedomainofPhysics。Referringtoastrangeassertion，that"saltwaterwilldissolvesaltputintoitinlesstimethanfreshwaterwilldissolveit，"heisatoncereadywithanexplanationtofitthecase。"Thesalt，"
hesays，"intheprecedentwaterdothbysimilitudeofsubstancedrawthesaltnewputinuntoit。"Again，inhisfinding，wellwateriswarmerinwinterthansummer，and"thecauseisthesubterraneanheatwhichshutclosein（asinwinter）isthemore，butifitperspire（asitdothinsummer）
itistheless。"ThiswasBacontheLord。Whatafallingoff——fromtheexperimentalist’spointofview——fromBacontheFriar！Wecanfancyhimwatchingafalconpoisedmotionlessinthesky，andreflectingonthatproblemwhichtothisdayfairlypuzzlesourablestscientists，settlingthematterinasentence:"Thecauseisthatfeathersdoepossessupwardattractions。"DuringfourhundredyearsprecedingLordVerulamphilosopherswouldhaveflownbyaidofabroomstick。Baconhimselfwouldhavemerelyparriedtheproblemwithaplatitude！
Atanyrate，physicists，eveninthebrilliantseventeenthcentury，madenomaterialprogresstowardsthenavigationoftheair，andthuspresentlyletthesimplemechanicstepinbeforethem。Erethatcenturyhadclosedsomethinginthenatureofflighthadbeenaccomplished。Itisexceedinglyhardtoarriveatactualfact，butitseemsprettyclearthatmorethanoneindividual，bystartingfromsomeeminence，couldlethimselffallintospaceandwafthimselfawayforsomedistancewithfairsuccessandsafety，ItisstatedthatanEnglishMonk，Elmerus，flewthespaceofafurlongfromatowerinSpain，afeatofthesamekindhavingbeenaccomplishedbyanotheradventurerfromthetopofSt。Mark’satVenice。
Intheseattemptsitwouldseemthattheprincipleoftheparachutewastosomeextentatleastbroughtintoplay。Ifalsocircumstantialaccountscanbecredited，itwouldappearthataworkingmodelofaflyingmachinewaspubliclyexhibitedbyoneJohnMullerbeforetheEmperorCharlesV。atNuremberg。
Whateverexaggerationorembellishmenthistorymaybeguiltyofitisprettyclearthatsomegenuineattemptsofapracticalandnotunsuccessfulnaturehadbeenmadehereandthere，andthesepromptedthefloweryandvisionaryBishopWilkinsalreadyquotedtopredictconfidentlythatthedaywasapproachingwhenit"wouldbeascommonforamantocallforhiswingsasforbootsandspurs。"
Wehavenowtoreturntothe"tamegoose"method，whichfounditsbestandboldestexponentinahumblecraftsman，bynameBesnier，livingatSable，abouttheyear1678。Thismechanicalgeniuswasbytradealocksmith，andmusthavebeenpossessedofsufficientskilltoconstructanefficientapparatusoutofsuchmaterialsascametohishand，ofthesimplestpossibledesign。Itmaybecomparedtotheearliesttypeofbicycle，theancient"boneshaker，"nowalmostforgottensavebythosewho，likethewriter，hadexperienceofitonitsfirstappearance。Besnier’swings，asitwouldappear，wereessentiallyapairofdouble—bladedpaddlesandnothingmore，roughlyresemblingthedouble—paddleofanold—fashionedcanoe，onlythebladeswerelarge，roughlyrectangular，andcurvedorhollowed。Theoperatorwouldcommencebystandingerectandbalancingthesepaddles，oneoneachshoulder，sothatthehollowsofthebladesshouldbetowardstheground。Theforwardpartofeachpaddlewasthengraspedbythehands，whilethehinderpartofeachwasconnectedtothecorrespondingleg。This，presumably，wouldbeeffectedafterthearmshadbeenraisedvertically，thelegattachmentbeingcontrivedinsomewaywhichexperiencewoulddictate。
Theflyerwasnowfullyequipped，andnothingremainedforhimsavetomountsomeeminenceand，throwinghimselfforwardintospaceandassumingthepositionofaflyingbird，tocommenceflappingandbeatingtheairwithareciprocalmotion。First，hewouldbuffettheairdownwardswiththeleftarmandrightlegsimultaneously，andwhiletheserecoveredtheirpositionwouldstrikewiththerighthandandleftleg，andsoonalternately。Withthiscrudemethodtheenterprisinginventorsucceededinraisinghimselfbyshortstagesfromoneheighttoanother，reachingthusthetopofahouse，whencehecouldpassoverothers，orcrossariverorthelike。
Theperfectingofhissystembecamethensimplyaquestionofpracticeandexperience，andhadyoungathletesonlybeentrainedfromearlyyearstothenewartitseemsreasonabletosupposethatsomecrudeapproachtohumanflightwouldhavebeeneffected。Modificationsandimprovementsinconstructionwouldsoonhavesuggestedthemselves，aswasthecasewiththebicycle，whichinitslatestdevelopmentscanscarcelyberecognisedasspringingfromtheprimitive"bone—shaker"ofthirty—threeyearsago。Wewouldsuggesttheideatothemoderninventor。Hewillinthesedays，ofcourse，findlightermaterialstohand。Thenhewilladoptsomelinkmotionforthelegsinplaceofleatherthongs，andwillhingethepaddlebladessothattheyopenoutwiththeforwardstroke，butcollapsewiththereturn。Thenlookonanotherthirty—threeyears——afreshgeneration——andouryouthofbothsexesmayfindapopularrecreationingracefulaerialexercise。Thepaceisnotlikelytobeexcessive，andmolestationsfromdisguisedpolicemen——notphysicallyadapted，bytheway，torapidflight——neednotbeapprehended。
OneofthebesttestsofBesnier’smeasureofsuccessissuppliedbythefactthathehadpupilsaswellasimitators。
FirstonthislistmustbementionedaMr。Baldwin，anamewhich，curiouslyenough，twiceoverinmoderntimescomesintotherecordsofboldaerialexploits。Thisindividual，itappears，purchasedaflyingoutfitofBesnierhimself，andsurpassedhismasterinachievement。AlittlelateroneDantecontrivedsomemodificationofthesameapparatus，withwhichhepursuedthenewmodeofprogresstillhemetwithafracturedthigh。
ButwhatevertheimitatorsofBesniermayhaveaccomplished，tothehonestsmithmustbeaccordedthefullcreditoftheirsuccess，andwithhissimple，butbrilliant，recordleftatfloodmark，thetideofprogressebbedbackagain，whilemankindruminatedoverthegreatprobleminapparentinactivity。Butnotforlong。Theair—pumpaboutthisperiodwasgiventotheworld，andchemistswerealreadybusyinvestigatingthenatureofgases。Cavallowasexperimentingonkindredlines，whileinourownlandtherivalgeniusesofPriestleyandCavendishwereclearingthewaytomakewithrespecttotheatmospherethemostimportantdiscoveryyetdreamedof。Inrecordingthisdawnofanewera，however，weshouldcertainlynotforgethow，acrosstheAtlantic，hadarisenaRumfordandaFranklin，whoselaboursweredestinedtothrowanall—importantsidelightonthepagesofprogresswhichwehavenowtochronicle。
CHAPTERII。THEINVENTIONOFTHEBALLOON。
ItwasaNovembernightoftheyear1782，inthelittletownofAnnonay，nearLyons。Twoyoungmen，StephenandJosephMontgolfier，therepresentativesofafirmofpapermakers，weresittingtogetherovertheirparlourfire。Whilewatchingthesmokecurlingupthechimneyonepropoundedanideabywayofasuddeninspiration:"Whyshouldn’tsmokebemadetoraisebodiesintotheair？"
Theworldwaswaitingforthisutterance，which，itwouldseem，wasonthetipofthetonguewithmanyothers。Cavendishhadalreadydiscoveredwhathedesignated"inflammableair，"thoughnoonehadasyetgivenititslatertitleofhydrogengas。
Moreover，intreatingofthisgas——Dr。BlackofEdinburgh，asmuchasfifteenyearsbeforethedatewehavenowarrivedat，hadsuggestedthatitshouldbemadecapableofraisingathinbladderintheair。Withashademoreofgoodfortune，ormaybewithamodicummoreofleisure，thelearnedDoctorwouldhavewontheinventionoftheballoonforhisowncountry。
Cavallocamealmostnearer，andactuallyputtingthesameideaintopractice，hadsucceededinthespringof1782inmakingsoapbubblesblownwithhydrogengasfloatupwards。Buthehadaccomplishednomorewhen，asrelated，intheautumnofthesameyearthebrothersMontgolfierconceivedthenotionofmakingbodies"levitate"bythesimplerexpedientoffillingthemwithsmoke。
Thiswasthecrudeidea，theapplicationofwhichintheirhandswassoonmarkedwithnotablesuccess。Theirowntradesuppliedreadyandsuitablematerialsforafirstexperiment，and，makinganoblongbagofthinpaperafewfeetinlength，theyproceededtointroduceacloudofsmokeintoitbyholdingcrumpledpaperkindledinachafingdishbeneaththeopenmouth。Whatasubjectistherehereforanimaginativepainter！Asthesmokycloudformedwithin，thebagdistendeditself，becamebuoyant，andpresentlyfloatedtotheceiling。
Thesimpletrialprovedacompletesuccess，due，asitappearedtothem，totheascensivepowerofacloudofsmoke。
Aninterestingandmoredetailedversionofthestoryisextant。Whiletheexperimentwasinprogressaneighbour，thewidowofatradesmanwhohadbeenconnectedinbusinesswiththefirm，seeingsmokeescapingintotheroom，enteredandstoodwatchingtheproceedings，whichwerenotunattendedwithdifficulties。Thebag，halfinflated，wasnoteasytoholdinpositionoverthechafingdish，andrapidlycooledandcollapsedonbeingremovedfromit。Thewidownotingthis，asalsotheperplexityoftheyoungmen，suggestedthattheyshouldtrytheresultoftyingthedishonatthebottomofthebag。Thiswastheonethingwantedtosecuresuccess，andthatgoodlady，whoseverynameisunhappilylost，deservesanhonouredplaceinhistory。Itwasunquestionablytheadoptionofherideawhichlaunchedthefirstballoonintospace。
Thesameexperimentrepeatedintheopenairprovingayetmorepronouncedsuccess，moreelaboratetrialswerequicklydeveloped，andtheinfantballoongrewfast。Oneworthyofthename，sphericalinshapeandofsome600cubicfeetcapacity，wasnowmadeandtreatedasbefore，withtheresultthatereitwasfullyinflateditbrokethestringsthathelditandsailedawayhundredsoffeetintotheair。Theinfantwasfastbecomingaprodigy。Encouragedbytheirfreshsuccess，theinventorsatoncesetaboutpreparationsfortheconstructionofamuchlargerballoonsomethirty—fivefeetdiameter（thatis，ofabout23，000cubicfeetcapacity），tobemadeoflinenlinedwithpaperandthismachine，launchedonafavourabledayinthefollowingspring，rosewithgreatswiftnesstofullyathousandfeet，andtravellednearlyamilefromitsstartingground。
Enough;thetimewasalreadyripeforapublicdemonstrationofthenewinvention，andaccordinglythe5thofthefollowingJunewitnessedtheascentofthesameballoonwithdueceremonyandadvertisement。Specialpainsweretakenwiththeinflation，whichwasconductedoverapitabovewhichtheballoonenvelopewasslung;andinaccordancewiththeviewthatsmokewasthechiefliftingpower，thefuelwascomposedofstrawlargelymixedwithwool。Itisrecordedthatthemanagementofthefurnaceneededtheattentionoftwomenonly，whileeightmencouldhardlyholdtheimpatientballooninrestraint。Theinflation，inspiteofthefactthatthefuelchosenwasscarcelythebestforthepurpose，wasconductedremarkableexpedition，andonbeingreleased，thecrafttravelledoneandahalfmilesintotheair，attainingaheightestimatedatover6，000feet。
Fromthistimethetideofeventsintheaeronauticalworldrollsoninfullflood，almosteveryhalf—yearmarkingafreshepoch，untilanewdepartureintheinfantartofballooningwasalreadyonthepointofbeingreached。IthadbeenerroneouslysupposedthattheascentoftheMontgolfierballoonhadbeendue，nottotherarefactionoftheairwithinit——whichwasitstruecause——buttotheevolutionofsomelightgasdisengagedbythenatureofthefuelused。Itfollowed，therefore，almostasamatterofcourse，thatchemists，who，asstatedinthelastchapter，werealreadyacquaintedwithso—called"inflammableair，"orhydrogengas，graspedthefactthatthisgaswouldservebetterthananyotherforthepurposesofaballoon。AndnosoonerhadthenewsoftheMontgolfiers’successreachedParisthanasubscriptionwasraised，andM。Charles，ProfessorofExperimentalPhilosophy，wasappointed，withtheassistanceofM。Roberts，tosuperintendtheconstructionofasuitableballoonanditsinflationbytheproposednewmethod。
Thetaskwasoneofconsiderabledifficulty，owingpartlytothenecessityofprocuringsomematerialwhichwouldpreventtheescapeofthelightestandmostsubtlegasknown，andnolessbyreasonofthedifficultyofpreparingunderpressureasufficientquantityofgasitself。Theexperiment，soundenoughintheory，waseventuallycarriedthroughafterseveralinstructivefailures。Asuitablematerialwasfoundin"lustring，"aglossysilkclothvarnishedwithasolutionofcaoutchouc，andthisbeingformedintoaballoononlythirteenfeetindiameterandfittedwithoutotheraperturethanastopcock，wasafterseveralattemptsfilledwithhydrogengaspreparedintheusualwaybytheactionofdilutesulphuricacidonscrapiron。
Thepreparationscompleted，onelastandall—importantmistakewasmadebyclosingthestop—cockbeforetheballoonwasdismissed，thedisastrousandunavoidableresultofthisbeingatthetimeoverlooked。
OnAugust25，1783，theballoonwasliberatedontheChampdeMarsbeforeanenormousconcourse，andinlessthantwominuteshadreachedanelevationofhalfamile，whenitwastemporarilylostincloud，throughwhich，however，itpenetrated，climbingintoyethighercloud，when，disappearingfromsight，itpresentlyburstanddescendedtoearthafterremainingintheairsomethree—quartersofanhour。
Theburstingofthislittlecrafttaughtthefutureballoonisthisfirstgreatlesson，namely，thatonleavingearthhemustopentheneckofhisballoon;andthereasonofthisisobvious。
Whileyetonearththeimprisonedgasofaproperlyfilledballoondistendsthesilkbyvirtueofitsexpansiveforce，andinspiteoftheenormousoutsidepressurewhichtheweightofairexertsuponit。Then，astheballoonriseshighintheairandtheoutsidepressuregrowsless，thestrugglinggaswithin，ifallowednovent，stretchestheballoonmoreandmoreuntiltheslenderfabricburstsunderthestrain。
Attheriskofbeingtedious，wehavedweltatsomelengthontheinitialexperimentswhichinlessthanasingleyearhadledtothediscoveryanddevelopmentoftwodistinctmethods——stillemployedandincompetitionwitheachother——ofdismissingballoonsintotheheavens。Wearenowpreparedtoenterfullyintotheromantichistoryofoursubjectwhichfromthispointrapidlyunfoldsitself。
SomeelevenmonthsonlyafterthetwoMontgolfierswerediscoveredtoyingwiththeirinflatedpaperbag，theyoungerofthetwobrotherswasengagedtomakeanexhibitionofhisnewartbeforetheKingatVersailles，andthiswasdestinedtobethefirstoccasionwhenaballoonwastocarryalivingfreightintothesky。Thestatelystructure，whichwasgorgeouslydecorated，toweredsomeseventyfeetintotheair，andwasfurnishedwithawickercarinwhichthepassengersweredulyinstalled。Thesewerethreeinnumber，asheep，acock，andaduck，andamidtheacclamationsofthemultitude，roseafewhundredfeetanddescendedhalfamileaway。Thecockwasfoundtohavesustainedanunexplainedmishap:itslegwasbroken;butthesheepwasfeedingcomplacently，andtheduckwasquackingwithmuchapparentsatisfaction。
Now，whoamongmortalswillcomeforwardandwinthehonourofbeingthefirsttosailtheskies？M。PilitredeRozieratoncevolunteered，andbythemonthofNovemberanewairshipwasbuilt，74feethigh，48feetinlargestdiameter，and15
feetacrosstheneck，outsidewhichawickergallerywasconstructed，whileanironbrazierwasslungbelowall。Buttotrimtheboatproperlytwopassengerswereneeded，anddeRozierfoundareadycolleagueintheMarquisd’Arlandes。Bywayofprecaution，deRoziermadeafewpreliminaryascentswiththeballoonheldcaptive，andthenthetwointrepidFrenchmentooktheirstandonoppositesidesofthegallery，eachfurnishedwithbundlesoffueltofeedthefurnace，eachalsocarryingalargewetspongewithwhichtoextinguishtheflameswheneverthemachinemightcatchfire。Oncastingofftheballoonrosereadily，andreaching3，000feet，driftedawayonanuppercurrent。
Therestofthenarrative，muchcondensedfromaletteroftheMarquis，writtenaweeklater，runssomewhatthus:"Ourdeparturewasatfifty—fourminutespastone，andoccasionedlittlestiramongthespectators。Thinkingtheymightbefrightenedandstandinneedofencouragement，Iwavedmyarm。
M。deRoziercried，’Youaredoingnothing，andwearenotrising！’Istirredthefire，andthenbegantoscantheriver，butPilitrecriedagain，’Seetheriver;wearedroppingintoit！’Weagainurgedthefire，butstillclungtotheriverbed。