the dominion of the air-第34部分

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ans　unreasonable　to　levy。　　The　　recognised　tariff　seems　to　have　been　20　centimes　for　4　grammes；　or　at　the　rate　of　not　greatly　more　than　a　shilling　per　English　ounce。　　Surely　hardly　on　a　par　with　famein　prices　in　a　time　of　siege。

It　has　already　been　stated　that　the　defenders　of　Paris　did　not　derive　substantial　assistance　from　the　services　of　such　a　reconnoitring　balloon　as　is　generally　used　in　warfare　at　every　available　opportunity。　　It　is　possible　that　the　peculiar　circumstances　of　the　investment　of　the　town　rendered　such　reconnaissance　of　comparatively　small　value。　　But；　at　any　rate；　it　seems　clear　that　due　opportunity　was　not　given　to　this　strategic　method。　　M。　Giffard；　who　at　the　commencement　of　the　siege　was　in　Paris；　and　whose　experience　with　a　captive　balloon　was　second　to　none；　made　early　overtures　to　the　Government；　offering　to　build　for　L40；000　a　suitable　balloon；　capable　of　raising　forty　persons　to　a　heightm　of　3；000　feet。　　Forty　aerial　scouts；　it　may　be　said；　are　hardly　needed　for　purposes　of　outlook　at　one　time；　but　it　appears　that　this　was　not　the　consideration　which　stood　in　the　way　of　M。　Giffard's　offer　being　accepted。　　According　to　M。　de　Fonvielle；　the　Government　refused　the　experienced　aeronaut's　proposal　on　the　ground　that　he　required　a　place　in　the　Champs　Elysees；　〃which　it　would　be　necessary　to　clear　of　a　few　shrubs〃！



CHAPTER　XIX。　THE　TRAGEDY　OF　THE　ZENITH。〃THE　NAVIGABLE　BALLOON


The　mechanical　air　ship　had；　by　this　time；　as　may　be　inferred；　begun　seriously　to　occupy　the　attention　of　both　theoretical　and　practical　aeronauts。　　One　of　the　earliest　machines　deserving　of　special　mention　was　designed　by　M。　Giffard；　and　consisted　of　an　elongated　balloon；　104　feet　in　length　and　39　feet　in　greatest　diameter；　furnished　with　a　triangular　rudder；　and　a　steam　engine　operating　a　screw。　　The　fire　of　the　engine；　which　burned　coke；　was　skilfully　protected；　and　the　fuel　and　water　required　were　taken　into　calculation　as　so　much　ballast　to　be　gradually　expended。　　In　this　vessel；　inflated　only　with　coal　gas；　and　somewhat　unmanageable　and　difficult　to　balance；　the　enthusiastic　inventor　ascended　alone　from　the　Hippodrome　and　executed　sundry　desired　movements；　not　unsuccessfully。　　But　the　trial　was　not　of　long　duration；　and　the　descent　proved　both　rapid　and　perilous。　　Had　the　trial　been　made　in　such　a　perfect　calm　as　that　which　prevailed　when　certain　subsequent　inventions　were　tested；　it　was　considered　that　M。　Giffard's　vessel　would　have　been　as　navigable　as　a　boat　in　the　water。　　This　unrivalled　mechanician；　after　having　made　great　advances　in　the　direction　of　high　speed　engines　of　sufficient　lightness；　proceeded　to　design　a　vastly　improved　dirigible　balloon；　when　his　endeavours　were　frustrated　by　blindness。

As　has　been　already　stated；　M。　Dupuy　de　Lome；　at　the　end　of　the　siege　of　Paris；　was　engaged　in　building　a　navigable　balloon；　which；　owing　to　the　unsettled　state　of　affairs　in　France；　did　not　receive　its　trial　till　two　years　later。　　This　balloon；　which　was　inflated　with　pure　hydrogen；　was　of　greater　capacity　than　that　of　M。　Giffard；　being　cigar　shaped　and　measuring　118　feet　by　48　feet。　　It　was　also　provided　with　an　ingenious　arrangement　consisting　of　an　internal　air　bag；　capable　of　being　either　inflated　or　discharged；　for　the　purpose　of　keeping　the　principal　envelope　always　distended；　and　thus　offering　the　least　possible　resistance　to　the　wind。　　The　propelling　power　was　the　manual　labour　of　eight　men　working　the　screw；　and　the　steerage　was　provided　for　by　a　triangular　rudder。　　The　trial；　which　was　carried　out　without　mishap；　took　place　in　February；　1872；　in　the　Fort　of　Vincennes；　under　the　personal　direction　of　the　inventor；　when　it　was　found　that　the　vessel　readily　obeyed　the　helm；　and　was　capable　of　a　speed　exceeding　six　miles　an　hour。

It　was　not　till　nine　years　after　this　that　the　next　important　trial　with　air　ships　was　made。　　The　brothers　Tissandier　will　then　be　found　taking　the　lead；　and　an　appalling　incident　in　the　aeronautical　career　of　one　of　these　has　now　to　be　recorded。

In　the　spring　of　1875；　and　with　the　co…operation　of　French　scientific　societies；　it　was　determined　to　make　two　experimental　voyages　in　a　balloon　called　the　〃Zenith；〃　one　of　these　to　be　of　long　duration；　the　other　of　great　height。　　The　first　of　these　had　been　successfully　accomplished　in　a　flight　of　twenty…four　hours'　duration　from　Paris　to　Bordeaux。　　It　was　now　April　the　15th；　and　the　lofty　flight　was　embarked　upon　by　M。　Gaston　Tissandier；　accompanied　by　MM。　Croce…Spinelli　and　Sivel。　　Under　competent　advice；　provision　for　respiration　on　emergency　was　provided　in　three　small　balloons；　filled　with　a　mixture　of　air　and　oxygen；　and　fitted　with　indiarubber　hose　pipes；　which　would　allow　the　mixture；　when　inhaled；　to　pass　first　through　a　wash　bottle　containing　aromatic　fluid。　　The　experiments　determined　on　included　an　analysis　of　the　proportion　of　carbonic　acid　gas　at　different　heights　by　means　of　special　apparatus；　spectroscopic　observations；　and　the　readings　registered　by　certain　barometers　and　thermometers。　A　novel　and　valuable　experiment；　also　arranged；　was　that　of　testing　the　internal　temperature　of　the　balloon　as　compared　with　that　of　the　external　air。

Ascending　at　11。30　a。m。　under　a　warm　sun；　the　balloon　had　by　1　p。m。　reached　an　altitude　of　16；000　feet；　when　the　external　air　was　at　freezing　point；　the　gas　high　in　the　balloon　being　72　degrees；　and　at　the　centre　66　degrees。　　Ere　this　height　had　been　fully　reached；　however；　the　voyagers　had　begun　to　breathe　oxygen。　　At　11。57；　an　hour　previously；　Spinelli　had　written　in　his　notebook；　〃Slight　pain　in　the　earssomewhat　oppressedit　is　the　gas。〃　　At　23；000　feet　Sivel　wrote　in　his　notebook；　〃I　am　inhaling　oxygenthe　effect　is　excellent；〃　after　which　he　proceeded　to　urge　the　balloon　higher　by　a　discharge　of　ballast。　　The　rest　of　the　terrible　narrative　has　now　to　be　taken　from　the　notes　of　M。　Tissandier；　and　as　these　constitute　one　of　the　most　thrilling　narratives　in　aeronautical　records　we　transcribe　them　nearly　in　full；　as　given　by　Mr。　Glaisher：

〃At　23；000　feet　we　were　standing　up　in　the　car。　　Sivel；　who　had　given　up　for　a　moment；　is　re…invigorated。　　Croce…Spinelli　is　motionless　in　front　of　me。。。。　I　felt　stupefied　and　frozen。　　I　wished　to　put　on　my　fur　gloves；　but；　without　being　conscious　of　it；　the　action　of　taking　them　from　my　pocket　necessitated　an　effort　that　I　could　no　longer　make。。。。　I　copy；　verbatim；　the　following　lines　which　were　written　by　me；　although　I　have　no　very　distinct　remembrance　of　doing　so。　　They　are　traced　in　a　hardly　legible　manner　by　a　hand　trembling　with　cold：　　'My　hands　are　frozen。　　I　am　all　right。　　We　are　all　all　right。　　Fog　in　the　horizon；　with　little　rounded　cirrus。　　We　are　ascending。　　Croce　pants；　he　inhales　oxygen。　　Sivel　closes　his　eyes。　　Croce　also　closes　his　eyes。。。。　Sivel　throws　out　ballast'these　last　words　are　hardly　readable。　　Sivel　seized　his　knife　and　cut　successively　three　cords；　and　the　three　bags　emptied　themselves　and　we　ascended　rapidly。　　The　last　remembrance　of　this　ascent　which　remains　clear　to　me　relates　to　a　moment　earlier。　　Croce…Spinelli　was　seated；　holding　in　one　hand　a　wash　bottle　of　oxygen　gas。　　His　head　was　slightly　inclined　and　he　seemed　oppressed。　　I　had　still　strength　to　tap　the　aneroid　barometer　to　facilitate　the　movement　of　the　needle。　　Sivel　had　just　raised　his　hand　towards　the　sky。　　As　for　myself；　I　remained　perfectly　still；　without　suspecting　that　I　had；　perhaps；　already　lost　the　power　of　moving。　　About　the　height　of　25；000　feet　the　condition　of　stupefaction　which　ensues　is　extraordinary。　　The　mind　and　body　weaken　by　degrees；　and　imperceptibly；　without　consciousness　of　it。　　No　suffering　is　then　experienced；　on　the　contrary；　an　inner　joy　is　felt　like　an　irradiation　from　the　surrounding　flood　of　light。　　　One　becomes　indifferent。　　One　thinks　no　more　of　the　perilous　position　or　of　danger。　　One　ascends；　and　is　happy　to　ascend。　　　The　vertigo　of　the　upper　regions　is　not　an　idle　word；　but；　so　far　as　I　can　judge　from　my　personal　impression；　vertigo　appears　at　the　last　moment；　it　immediately　precedes　annihilation；　sudden；　unexpected；　and　irresistible。

〃When　Sivel　cut　away　the　bags　of　ballast　at　the　height　of　about　24；000　feet；　I　seemed　to　remember　that　he　was　sitting　at　the　bottom　of　the　car；　and　nearly　in　the　same　position　as　Croce…Spinelli。　　For　my　part；　I　was　in　the　angle　of　the　car；　thanks　to　which　support　I　was　able　to　hold　up；　but　I　soon　felt　too　weak　even　to　turn　my　head　to　look　at　my　companions。　　Soon　I　wished　to　take　hold　of　the　tube　of　oxygen；　but　it　was　impossible　to　raise　my　arm。　　My　mind；　nevertheless；　was　quite　clear。　　I　wished　to　explain；　'We　are　8；000　metres　high'；　but　my　tongue　was；　as　it　were；　paralysed。　　All　at　once　I　closed　my　eyes；　and；　sinking　down　inert；　became　insensible。　　This　was　about　1。30　p。m。　　At　2。8　p。m。　I　awoke　for　a　moment；　and　found　the　balloon　rapidly　descending。　　I　was　able　to　cut　away　a　bag　of　ballast　to　check　the　speed　and　write　in　my　notebook　the　following　lines；　which　I　copy：

〃　'We　are　descending。　　Temperature；　3　degrees。　　I　throw　out　ballast。　　Barometer；　12。4　inches。　　We　are　descending。　　Sivel　and　Croce　still　in　a　fainting　state　at　the　bottom　of　the　car。　　Descending　very　rapidly。'

〃Hardly　had　I　written　these　lines　when　a　kind　of　trembling　seized　me；　and　I　fell　back　weakened　again。　　There　was　a　violent　wind　from　below；　upwards；　denoting　a　very　rapid　descent。　　After　some　minutes　I　felt　myself　shaken　by　the　arm；　and　I　recognised　Croce；　who　had　revived。　　'Throw　out　ballast；'　he　said　to　me；　'we　are　descending　'；　but　I　could　hardly　open　my　eyes；　and　did　not　see　whether　Sivel　was　awake。　　I　called　to　mind　that　Croce　unfastened　the　aspirator；　which　he　then　threw　overboard；　and　then　he　threw　out　ballast；　rugs；　etc。

〃All　this　is　an　extremely　confused　remembrance；　quickly　extinguished；　for　again　I　fell　back　inert　more　completely　than　before；　and　it　seemed　to　me　that　I　was　dying。　　What　happened？　It　is　certain　that　the　balloon；　relieved　of　a　great　weight　of　ballast；　at　once　ascended　to　the　higher　regions。

〃At　3。30　p。m。　I　opened　my　eyes　again。　　I　felt　dreadfully　giddy　and　oppressed；　but　gradually　came　to　myself。　　The　balloon　was　descending　with　frightful　speed　and　making　great　oscillations。　　I　crept　along　on　my