the dominion of the air-第29部分

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ted　by　Dr。　T。　L。　Phipson；　is　edited　by　Mr。　Glaisher；　and　many　of　the　experiences　he　relates　will　be　found　to　contrast　with　those　of　others。　　His　physical　symptoms　alone　were　remarkable；　for　on　one　occasion；　at　an　altitude　of　apparently　little　over　10；000　feet；　he　became　unwell　being　affected　with　a　sensation　of　drowsiness；　palpitation；　shortness　of　breath；　and　singing　in　the　ears；　which；　after　landing　gave　place　to　a　〃fit　of　incessant　gaping〃　while　he　states　that　in　later　voyages；　at　but　slightly　greater　altitudes；　his　throat　and　lungs　became　affected；　and　he　was　troubled　with　presence　of　blood　upon　the　lips。　　This　draws　forth　a　footnote　from　Mr。　Glaisher；　which　should　be　commended　to　all　would…be　sky　voyagers。　　It　runs　thus：〃I　have　never　experienced　any　of　these　effects　till　I　had　long　passed　the　heights　reached　by　M。　Flammarion；　and　at　no　elevation　was　there　the　presence　of　blood。〃　　However；　M。　Flammarion　adduces；　at　least；　one　reassuring　fact；　which　will　be　read　with　interest。　　Once；　having；　against　the　entreaties　of　his　friends；　ascended　with　an　attack　of　influenza　upon　him；　he　came　down　to　earth　again　an　hour　or　two　afterwards　with　this　troublesome　complaint　completely　cured。

It　would　seem　as　if　the　soil　of　France　supplied　the　aeronaut　with　certain　phenomena　not　known　in　England；　one　of　these　apparently　being　the　occasional　presence　of　butterflies　hovering　round　the　car　when　at　considerable　heights。　　M。　Flammarion　mentions　more　than　one　occasion　when　he　thus　saw　them；　and　found　them　to　be　without　sense　of　alarm　at　the　balloon　or　its　passengers。　　Again；　the　French　observer　seems　seldom　to　have　detected　those　opposite　airstreams　which　English　balloonists　may　frequently　observe；　and　have　such　cause　to　be　wary　of。　　His　words；　as　translated；　are：〃　t　appears　to　me　that　two　or　more　currents；　flowing　in　different　directions；　are　very　rarely　met　with　as　we　rise　in　the　air；　and　when　two　layers　of　cloud　appear　to　travel　in　opposite　directions　the　effect　is　generally　caused　by　the　motion　of　one　layer　being　more　rapid　than　the　other；　when　the　latter　appears　to　be　moving　in　a　contrary　direction。〃　　In　continuation　of　these　experiences；　he　speaks　of　an　occasion　when；　speeding　through　the　air　at　the　rate　of　an　ordinary　express　train；　he　was　drawn　towards　a　tempest　by　a　species　of　attraction。

The　French　aeronaut's　estimate　of　what　constitutes　a　terrific　rate　of　fall　differs　somewhat　from　that　of　others　whose　testimony　we　have　been　recording。　　In　one　descent；　falling　（without　reaching　earth；　however）　a　distance　of　2；130　feet　in　two　minutes；　he　describes　the　earth　rising　up　with　frightful　rapidity；　though；　as　will　be　observed；　this　is　not　nearly　half　the　speed　at　which　either　Mr。　Glaisher　or　Albert　Smith　and　his　companions　were　precipitated　on　to　bare　ground。　　Very　many　cases　which　we　have　cited　go　to　show　that　the　knowledge　of　the　great　elasticity　of　a　well…made　wicker　car　may　rob　a　fall　otherwise　alarming　of　its　terrors；　while　the　practical　certainty　that　a　balloon　descending　headlong　will　form　itself　into　a　natural　parachute；　if　properly　managed；　reduces　enormously　the　risk　attending　any　mere　impact　with　earth。　　It　will　be　allowed　by　all　experienced　aeronauts　that　far　worse　chances　lie　in　some　awkward　alighting　ground；　or　in　the　dragging　against　dangerous　obstacles　after　the　balloon　has　fallen。

Many　of　M。　Flammarion's　experiments　are　remarkable　for　their　simplicity。　　Indeed；　in　some　cases　he　would　seem　to　have　applied　himself　to　making　trials　the　result　of　which　could　not　have　been　seriously　questioned。　　The　following；　quoting　from　Dr。　Phipson's　translation；　will　serve　as　an　example：

〃Another　mechanical　experiment　was　made　in　the　evening；　and　renewed　next　day。　　I　wished　to　verify　Galileo's　principle　of　the　independence　of　simultaneous　motions。　　According　to　this　principle；　a　body　which　is　allowed　to　fall　from　another　body　in　motion　participates　in　the　motion　of　the　latter；　thus；　if　we　drop　a　marble　from　the　masthead　of　a　ship；　it　preserves　during　its　fall　the　rate　of　motion　of　the　vessel；　and　falls　at　the　foot　of　the　mast　as　if　the　ship　were　still。　　Now；　if　a　body　falls　from　a　balloon；　does　it　also　follow　the　motion　of　the　latter；　or　does　it　fall　directly　to　the　earth　in　a　line　which　is　perpendicular　to　the　point　at　which　we　let　it　fall？　　In　the　first　case　its　fall　would　be　described　by　an　oblique　line。　The　latter　was　found　to　be　the　fact；　as　we　proved　by　letting　a　bottle　fall。　　During　its　descent　it　partakes　of　the　balloon's　motion；　and　until　it　reaches　the　earth　is　always　seen　perpendicularly　below　the　car。〃

An　interesting　phenomenon；　relating　to　the　formation　of　fog　was　witnessed　by　M。　Flammarion　in　one　of　his　voyages。　　He　was　flying　low　with　a　fast　wind；　and　while　traversing　a　forest　he　noticed　here　and　there　patches　of　light　clouds；　which；　remaining　motionless　in　defiance　of　the　strong　wind；　continued　to　hang　above　the　summits　of　the　trees。　　The　explanation　of　this　can　hardly　be　doubtful；　being　analogous　to　the　formation　of　a　night…cap　on　a　mountain　peak　where　warm　moist　air…currents　become　chilled　against　the　cold　rock　surface；　forming；　momentarily；　a　patch　of　cloud　which；　though　constantly　being　blown　away；　is　as　constantly　re…formed；　and　thus　is　made　to　appear　as　if　stationary。

The　above　instructive　phenomenon　could　hardly　have　been　noticed　save　by　an　aeronaut；　and　the　same　may　be　said　of　the　following。　　Passing　in　a　clear　sky　over　the　spot　where　the　Marne　flows　into　the　Seine；　M。　Flammarion　notes　that　the　water　of　the　Marne；　which；　as　he　says；　is　as　yellow　now　as　it　was　in　the　time　of　Julius　Caesar；　does　not　mix　with　the　green　water　of　the　Seine；　which　flows　to　the　left　of　the　current；　nor　with　the　blue　water　of　the　canal；　which　flows　to　the　right。　　Thus；　a　yellow　river　was　seen　flowing　between　two　distinct　brooks；　green　and　blue　respectively。

Here　was　optical　evidence　of　the　way　in　which　streams　of　water　which　actually　unite　may　continue　to　maintain　independent　courses。　　We　have　seen　that　the　same　is　true　of　streams　of　air；　and；　where　these　traverse　one　another　in　a　copious　and　complex　manner；　we　find；　as　will　be　shown；　conditions　produced　that　cause　a　great　deadening　of　sound；　thus；　great　differences　in　the　travel　of　sound　in　the　silent　upper　air　can　be　noticed　on　different　days；　and；　indeed；　in　different　periods　of　the　same　aerial　voyage。　　M。　Flammarion　bears　undeniable　testimony　to　the　manner　in　which　the　equable　condition　of　the　atmosphere　attending　fog　enhances；　to　the　aeronaut；　the　hearing　of　sounds　from　below。　　But　when　he　gives　definite　heights　as　the　range　limits　of　definite　sounds　it　must　be　understood　that　these　ranges　will　be　found　to　vary　greatly　according　to　circumstances。　　Thus；　where　it　is　stated　that　a　man's　voice　may　make　itself　heard　at　3；255　feet；　it　might　be　added　that　sometimes　it　cannot　be　heard　at　a　considerably　less　altitude；　and；　again；　the　statement　that　the　whistle　of　a　locomotive　rises　to　near　10；000　feet；　and　the　noise　of　a　railway　train　to　8；200　feet；　should　be　qualified　an　additional　note　to　the　effect　that　both　may　be　occasionally　heard　at　distances　vastly　greater。　　But　perhaps　the　most　curious　observation　of　M。　Flammarion　respecting　sounds　aloft　relates　to　that　of　echo。　　To　his　fancy；　this　had　a　vague　depth；　appearing　also　to　　rise　from　the　horizon　with　a　curious　tone；　as　if　it　came　from　another　world。　　To　the　writer；　on　the　contrary；　and　to　many　fellow　observers　who　have　specially　experimented　with　this　test　of　sound；　the　echo　has　always　appeared　to　come　very　much　from　the　right　placethe　spot　nearly　immediately　belowand　if　this　suggested　its　coming　from　another　world　then　the　same　would　have　to　be　said　of　all　echoes　generally。

About　the　same　period　when　M。　Flammarion　was　conducting　his　early　ascents；　MM。　de　Fonvielle　and　Tissandier　embarked　on　experimental　voyages；　which　deserve　some　particular　notice。　　Interest　in　the　new　revival　of　the　art　of　aeronautics　was　manifestly　be　coming　reestablished　in　France；　and　though　we　find　enthusiasts　more　than　once　bitterly　complaining　of　the　lack　of　financial　assistance；　still　ballooning　exhibitions；　wherever　accomplished；　never　failed　to　arouse　popular　appreciation。　　But　enthusiasm　was　by　no　means　the　universal　attitude　with　which　the　world　regarded　aerial　enterprise。　　A　remarkable　and　instructive　instance　is　given　to　the　contrary　by　M。　W。　de　Fonvielle　himself。

He　records　an　original　ballooning　exploit；　organised　at　Algiers；　which　one　might　have　supposed　would　have　caused　a　great　sensation；　and　to　which　he　himself　had　called　public　attention　in　the　local　journals。　　The　brothers　Braguet　were　to　make　an　ascent　from　the　Mustapha　Plain　in　a　small　fire　balloon　heated　with　burning　straw；　and　this　risky　performance　was　successfully　carried　out　by　the　enterprising　aeronauts。　　But；　to　the　onlooker；　the　most　striking　feature　of　the　proceeding　was　the　fact　that　while　the　Europeans　present　regarded　the　spectacle　with　curiosity　and　pleasure；　the　native　Mussulmans　did　not　appear　to　take　the　slightest　interest　in　it；　〃And　this；〃　remarked　de　Fonvielle；　〃was　not　the　first　time　that　ignorant　and　fanatic　people　have　been　noted　as　manifesting　complete　indifference　to　balloon　ascents。　　After　the　taking　of　Cairo；　when　General　Buonaparte　wished　to　produce　an　effect　upon　the　inhabitants；　he　not　only　made　them　a　speech；　but　supplemented　it　with　the　ascent　of　a　fire　balloon。　　The　attempt　was　a　complete　failure；　for　the　French　alone　looked　up　to　the　clouds　to　see　what　became　of　the　balloon。〃

In　the　summer　of　1867　an　attempt　was　made　to　revive　the　long　extinct　Aeronautic　Company　of　France；　established　by　De　Guyton。　　The　undertaking　was　worked　with　considerable　energy。　　Some　forty　or　fifty　active　recruits　were　pressed　into　the　service；　a　suitable　captive　balloon　was　obtained；　thousands　of　spectators　came　to　watch　the　evolutions；　and　many　were　found　to　pay　the　handsome　fee　of　100　francs　for　a　short　excursion　in　the　air。　For　all　this；　the　effort　was　entirely　abortive；　and　the　ballooning　corps；　as　such；　dropped　out　of　existence。

A　little　while　after　this　de　Fonvielle；　on　a　visit　to　England；　had　a　most　pathetic　interview　with　the　veteran　Charles　Green；　who　was　living　in　comfortable　retirement　at　Upper　Holloway。　　The　grand　old　man　pointed　to　a　well…filled　portfolio　in　the　c