the dominion of the air-第57部分

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Brearey　was　one　of　the　most　successful　inventors　of　flying　models。　　Mr。　Chanute；　speaking　as　President　of　the　American　Society　of　Civil　Engineers；　paid　him　a　high　and　well…deserved　compliment　in　saying　that　it　was　through　his　influence　that　aerial　navigation　had　been　cleared　of　much　rubbish　and　placed　upon　a　scientific　and　firm　basis。

Another　community　devoting　itself　to　the　pursuit　of　balloon　trips　and　matters　aeronautical　generally　is　the　newly…formed　Aero　Club；　of　whom　one　of　the　most　prominent　and　energetic　members　is　the　Hon。　C。　S。　Rolls。

It　had　been　announced　that　M。　Santos…Dumont　would　bring　an　air　ship　to　England；　and　during　the　summer　of　the　present　year　would　give　exhibitions　of　its　capability。　　It　was　even　rumoured　that　he　might　circle　round　St。　Paul's　and　accomplish　other　aerial　feats　unknown　in　England。　　The　promise　was　fulfilled　so　far　as　bringing　the　air　ship　to　England　was　concerned；　for　one　of　his　vessels　which　had　seen　service　was　deposited　at　the　Crystal　Palace。　　In　some　mysterious　manner；　however；　never　sufficiently　made　clear　to　the　public；　this　machine　was　one　morning　found　damaged；　and　M。　Santos…Dumont　has　withdrawn　from　his　proposed　engagements。

In　thus　doing　he　left　the　field　open　to　one　of　our　own　countrymen；　who；　in　his　first　attempt　at　flight　with　an　air　ship　of　his　own　invention　and　construction；　has　proved　himself　no　unworthy　rival　of　the　wealthy　young　Brazilian。

Mr。　Stanley　Spencer；　in　a　very　brief　space　of　time；　designed　and　built　completely　in　the　workshops　of　the　firm　an　elongated　motor　balloon；　75　feet　long　by　20　feet　diameter；　worked　by　a　screw　and　petrol　motor。　　This　motor　is　placed　in　the　prow；　25　feet　away　from；　and　in　front　of；　the　safety　valve；　by　which　precaution　any　danger　of　igniting　the　escaping　gas　is　avoided。　　Should；　however；　a　collapse　of　the　machine　arise　from　any　cause；　there　is　an　arrangement　for　throwing　the　balloon　into　the　form　of　a　parachute。　　Further；　there　is　provided　means　for　admitting　air　at　will　into　the　balloon；　by　which　the　necessity　for　much　ballast　is　obviated。

Mr。　Spencer　having　filled　the　balloon　with　pure　hydrogen；　made　his　first　trial　with　this　machine　late　in　an　evening　at　the　end　of　June。　　The　performance　of　the　vessel　is　thus　described　in　the　Westminster　Gazette：〃The　huge　balloon　filled　slowly；　so　that　the　light　was　rapidly　failing　when　at　last　the　doors　of　the　big　shed　slid　open　and　the　ship　was　brought　carefully　out；　her　motor　started；　and　her　maiden　voyage　commenced。　　With　Mr。　Stanley　Spencer　in　the　car；　she　sailed　gracefully　down　the　football　field；　wheeled　round　in　a　circlea　small　circle；　tooand　for　perhaps　a　quarter　of　an　hour　sailed　a　tortuous　course　over　the　heads　of　a　small　but　enthusiastic　crowd　of　spectators。　　The　ship　was　handicapped　to　some　extent　by　the　fact　that　in　their　anxiety　to　make　the　trial　the　aeronauts　had　not　waited　to　inflate　it　fully；　but　still　it　did　its　work　well；　answered　its　helm　readily；　showed　no　signs　of　rolling；　and；　in　short；　appeared　to　give　entire　satisfaction　to　everybody　concernedso　much　so；　indeed；　that　Mr。　Stanley　Spencer　informed　the　crowd　after　the　ascent　that　he　was　quite　ready　to　take　up　any　challenge　that　M。　Santos　Dumont　might　throw　down。〃　Within　a　few　weeks　of　this　his　first　success　Mr。　Spencer　was　able　to　prove　to　the　world　that　he　had　only　claimed　for　his　machine　what　its　powers　fully　justified。　　On　a　still　September　afternoon；　ascending　alone；　he　steered　his　aerial　ship　in　an　easy　and　graceful　flight　over　London；　from　the　Crystal　Palace　to　Harrow。



CHAPTER　XXIX。　　CONCLUSION。


The　future　development　of　aerostation　is　necessarily　difficult　to　forecast。　　Having　reviewed　its　history　from　its　inception　we　have　to　allow　that　the　balloon　in　itself；　as　an　instrument　of　aerial　locomotion；　remains　practically　only　where　it　was　120　years　ago。　　Nor；　in　the　nature　of　the　case；　is　this　to　be　wondered　at。　　The　wind；　which　alone　guides　the　balloon；　is　beyond　man's　control；　while；　as　a　source　of　lifting　power；　a　lighter　and　therefore　more　suitable　gas　than　hydrogen　is　not　to　be　found　in　nature。

It　is；　however；　conceivable　that　a　superior　mode　of　inflation　may　yet　be　discovered。　　Now　that　the　liquefaction　of　gases　has　become　an　accomplished　fact；　it　seems　almost　theoretically　possible　that　a　balloonist　may　presently　be　able　to　provide　himself　with　an　unlimited　reserve　of　potential　energy　so　as　to　be　fitted　for　travel　of　indefinite　duration。　　Endowed　with　increased　powers　of　this　nature；　the　aeronaut　could　utilise　a　balloon　for　voyages　of　discovery　over　regions　of　the　earth　which　bar　man's　progress　by　any　other　mode　of　travel。　　A　future　Andree；　provided　with　a　means　of　maintaining　his　gas　supply　for　six　weeks；　need　have　no　hesitation　in　laying　his　course　towards　the　North　Pole；　being　confident　that　the　winds　must　ultimately　waft　him　to　some　safe　haven。　　He　could；　indeed；　well　afford；　having　reached　the　Pole；　to　descend　and　build　his　cairn；　or　even　to　stop　a　week；　if　he　so　desired；　before　continuing　on　his　way。

But　it　may　fairly　be　claimed　for　the　balloon；　even　as　it　now　is；　that　a　great　and　important　future　is　open　to　it　as　a　means　for　exploring　inaccessible　country。　　It　may；　indeed；　be　urged　that　Andree's　task　was；　in　the　very　nature　of　the　case；　well　nigh　impracticable；　and　his　unfortunate　miscarriage　will　be　used　as　argument　against　such　a　method　of　exploration。　　But　it　must　always　be　remembered　that　in　Andree's　case　the　rigours　of　climate　which　he　was　compelled　to　face　were　the　most　serious　of　all　obstacles　to　balloon　travel。　　The　extreme　cold　would　not　only　cause　constant　shrinkage　of　the　gas；　but　would　entail　the　deposition　of　a　weight　of　moisture；　if　not　of　snow；　upon　the　surface　of　the　balloon；　which　must　greatly　shorten　its　life。

It　would　be　entirely　otherwise　if　the　country　it　were　sought　to　explore　were　in　lower　latitudes；　in　Australia；　or　within　the　vast　unknown　belt　of　earth　lying　nearer　the　equator。　　The　writer's　scheme　for　exploring　the　wholly　unknown　regions　of　Arabia　is　already　before　the　public。　　The　fact；　thought　to　be　established　by　the　most　experienced　aeronauts　of　old　times；　and　already　referred　to　in　these　pages；　that　at　some　height　a　strong　west　wind　is　to　be　found　blowing　with　great　constancy　all　round　the　globe；　is　in　accordance　with　the　view　entertained　by　modern　meteorologists。　　Such　a　wind；　too；　may　be　expected　to　be　a　fairly　fast　wind；　the　calculation　being　that；　as　a　general　rule；　the　velocity　of　currents　increases　from　the　ground　at　the　rate　of　about　three　miles　per　hour　for　each　thousand　feet　of　height；　thus　the　chance　of　a　balloon　drifting　speedily　across　the　breadth　of　Arabia　is　a　strong　one；　and；　regarded　in　this　light；　the　distance　to　be　traversed　is　certainly　not　excessive；　being　probably　well　within　the　lasting　power　of　such　a　balloon　as　that　employed　by　Andree。　　If；　for　the　sake　of　gas　supply；　Aden　were　chosen　for　the　starting　ground；　then　1；200　miles　E。N。E。　would　carry　the　voyager　to　Muscat；　1；100　miles　N。E。　by　E。　would　land　him　at　Sohar；　while　some　800　miles　would　suffice　to　take　him　to　the　seaboard　if　his　course　lay　N。E。　　It　must　also　be　borne　in　mind　that　the　Arabian　sun　by　day；　and　the　heat　radiated　off　the　desert　by　night；　would　be　all　in　favour　of　the　buoyancy　of　the　balloon。

But　there　are　other　persistent　winds　that；　for　purposes　of　exploration；　would　prove　equally　serviceable　and　sure。　　From　time　immemorial　the　dweller　on　the　Nile　has　been　led　to　regard　his　river　in　the　light　of　a　benignant　deity。　　If　he　wished　to　travel　down　its　course　he　had　but　to　entrust　his　vessel　to　the　stream；　and　this　would　carry　him。　　If；　again；　he　wished　to　retrace　his　course；　he　had　but　to　raise　a　sail；　and　the　prevalent　wind；　conquering　the　flood；　would　bear　him　against　the　stream。　　This　constant　north　wind；　following　the　Nile　valley；　and　thence　trending　still　southward　towards　Uganda；　has　been　regarded　as　a　means　to　hand　well　adapted　for　the　exploration　of　important　unsurveyed　country　by　balloon。　　This　scheme　has　been　conceived　and　elaborated　by　Major　B。F。S。　　Baden…Powell；　and；　so　far；　the　only　apparent　obstacle　in　the　way　has　proved　the　lack　of　necessary　funds。

It　will　be　urged；　however；　that　for　purposes　of　exploration　some　form　of　dirigible　balloon　is　desirable；　and　we　have　already　had　proof　that　where　it　is　not　sought　to　combat　winds　strongly　opposed　to　their　course　such　air　ships　as　Santos…Dumont　or　Messrs。　Spencer　have　already　constructed　acquit　themselves　well；　and　it　requires　no　stretch　of　imagination　to　conceive　that　before　the　present　century　is　closed　many　great　gaps　in　the　map　of　the　world　will　have　been　filled　in　by　aerial　survey。

But；　leaving　the　balloon　to　its　proper　function；　we　turn　to　the　flying　machine　properly　so　called　with　more　sanguine　hopes　of　seeing　the　real　conquest　of　the　air　achieved。　　It　was　as　it　were　but　yesterday　when　the　air　ship；　unhampered　by　huge　globes　of　gas；　and　controlled　by　mechanical　means　alone；　was　first　fairly　tried；　yet　it　is　already　considered　by　those　best　able　to　judge　that　its　ultimate　success　is　assured。

This　success　rests　now　solely　in　the　hands　of　the　mechanical　engineer。　　He　must；　and　surely　can；　build　the　ship　of　such　strength　that　some　essential　part　does　not　at　the　critical　moment　break　down　or　carry　away。