aeroplanes and dirigibles of war- 第11部分

reaching　them　from　below。　　In　other　words；　the　corsair　in　the

skies　depends　more　upon　compass　and　sound　than　upon　compass　and

vision　when　operating　after　dark。　　The　searchlights　with　which

the　Zeppelins　are　equipped　are　provided　merely　for　illuminating

a　supposed　position。　　They　are　not　brought　into　service　until

the　navigator　concludes　that　he　has　arrived　above　the　desired

point：　the　ray　of　light　which　is　then　projected　is　merely　to

assist　the　crew　in　the　discharge　of　the　missiles　of　destruction。



The　Zeppelin；　however；　owing　to　its　speed；　both　in　the　horizontal

and　vertical　planes；　is　essentially　a　unit　for　daylight

operations。　　The　other　airships　which　Germany　possesses；　and

which　for　the　most　part　are　of　the　non…rigid　type；　are　condemned

to　daylight　operations　from　the　character　of　their　design。　　Owing

to　their　low　speeds　they　may　be　dismissed　as　impossible　aerial

vessels　for　hazardous　work　and　are　not　regarded　by　the　German

authorities　as　all…round　airships　of　war。



Craft　of　the　air　are　judged　in　Germany　from　the　one　standard

only。　　This　may　be　a　Teutonic　failing；　but　it　is　quite　in　keeping

with　the　Teutonic　spirit　of　militarism。　　Commercialism　is　a

secondary　factor。　　To　the　German　Emperor　an　airship　is　much　what

a　new　manufacturing　process　or　machine　is　to　the　American。　

Whereas　the　latter　asks；　〃How　much　will　it　save　me　on　the

dollar？〃　to　the　War　Lord　of　Germanyand　an　airship

notwithstanding　its　other　recommendatory　features　is　judged

solely　from　this　standpointthe　question　is　〃What　are　its

military　qualifications？〃



When　the　semi…rigid　airship　〃V…I〃　was　brought　before　the　notice

of　the　German　military　department　the　pressing　point　concerning

its　military　recommendations　arose　at　once。　　The　inventor　had

foreseen　this　issue　and　was　optimistic。　　Thereupon　the

authorities　asked　if　the　inventor　were　prepared　to　justify　his

claims。　　The　retort　was　positive。　　Forthwith　the　Junkers　decided

to　submit　it　to　the　test。



This　ship　is　of　quite　a　distinctive　type。　　It　is　an　aerial

cruiser；　and　the　inventor　claims　that　it　combines　all　the

essential　qualifications　of　the　Zeppelin　and　of　the　competitors

of　the　latter；　in　addition　to　the　advantage　of　being　capable　of

dissection；　transportation　in　parts；　and　rapid　re…erection　at　any

desired　spot。　　The　length　of　the　vessel　is　about　270　feet；

maximum　diameter　approximately　42　feet；　and　capacity　about

300；000　cubic　feet。　　The　outstanding　feature　is　a　rigid

keel…frame　forming　a　covered　passage　way　below　the　envelope　or

gas…bag；　combined　with　easy　access　to　all　parts　of　the　craft

while　under　way；　together　with　an　artificial　stiffening　which

dispenses　with　the　necessity　of　attaching　any　additional　cars。　

The　frame　is　so　designed　that　the　load；　as　well　as　the　ballast

and　fuel　tanks；　may　be　distributed　as　desired；　and　at　the　same

time　it　ensures　an　advantageous　disposition　of　the　steering

mechanism；　far　removed　from　the　centre　of　rotation　at　the　stern；

without　any　overloading　of　the　latter。



The　lifting　part　of　the　airship　comprises　a　single　gas　bag　fitted

with　two　ballonets　provided　to　ensure　the　requisite　gas…tension

in　the　main　envelope；　while　at　the　same　time　permitting；　in　times

of　emergency；　a　rapid　change　of　altitude。　　Self…contained　blowers

contribute　to　the　preservation　of　the　shape　of　the　envelope；　the

blowers　and　the　ballonets　being　under　the　control　of　the　pilot。　

Planes　resembling　Venetian　blinds　facilitate　vertical　steering；

while　the　suspension　of　the　keel　is　carried　out　in　such　a　manner

as　to　secure　uniformity　of　weight　upon　the　gas　bag。　　The

propelling　power　comprises　two　sets　of　internal　combustion

engines；　each　developing　130　horse…power；　the　transmission　being

through　rubber　belting。　　The　propellers；　built　of　wood；　make　350

revolutions　per　minute；　and　are　set　as　closely　as　possible　to　the

centre　of　resistance。



But　the　most　salient　characteristic　of　this　machine　is　its

portability。　　It　can　be　dismantled　and　transported　by　wagons　to

any　desired　spot；　the　suspension　frame　being　constructed　in

units；　each　of　which　is　sufficiently　small　to　be　accommodated　in

an　ordinary　vehicle。　　Upon　arrival　the　parts　may　be　put　together

speedily　and　easily。　　The　authorities　submitted　the　airship　to

exacting　trials　and　were　so　impressed　by　its　characteristics　and

the　claims　of　the　inventor　that　undoubtedly　it　will　be　brought

into　service　during　the　present　crisis。



At　the　same　time　the　whole　faith　of　the　German　military　staff　so

far　as　airship　operations　are　concerned；　is　pinned　to　the

Zeppelin。　　Notwithstanding　its　many　drawbacks　it　is　the　vessel

which　will　be　used　for　the　invasion　of　Great　Britain。　　Even　the

harbour　question；　which　is　admitted　to　be　somewhat　acute；　has

been　solved　to　a　certain　degree。　　At　strategical　points　permanent

harbours　or　airship　sheds　have　been　established。　　Seeing　that　the

airships　demand　considerable　skill　in　docking　and　undocking；　and

that　it　is　impossible　to　achieve　these　operations　against　the

wind；　swinging　sheds　have　been　adopted。



On　water　the　practice　is　to　anchor　a　floating　harbour　at　one　end；

leaving　the　structure　to　swing　round　with　the　wind。　　But　on　dry

land　such　a　dock　is　impossible。　　Accordingly　turntable　sheds

have　been　adopted。　　The　shed　is　mounted　upon　a　double　turn…table；

there　being　two　circular　tracks　the　one　near　the　centre　of　the

shed　and　the　other　towards　its　extremities。　　The　shed　is　mounted

upon　a　centre　pivot　and　wheels　engaged　with　these　inner　and　outer

tracks。　　In　this　manner　the　shed　may　be　swung　round　to　the　most

favourable　point　of　the　compass　according　to　the　wind。



In　the　field；　however；　such　practices　are　impossible；　and　the

issue　in　this　connection　has　been　overcome　by　recourse　to　what

may　be　termed　portable　harbours。　　They　resemble　the　tents　of

peripatetic　circuses　and　travelling　exhibitions。　　There　is　a

network　of　vertical　steel　members　which　may　be　set　with　facility

and　speed　and　which　are　stayed　by　means　of　wire　guys。　　At　the　top

of　the　outer　vertical　posts　pulleys　are　provided　whereby　the

outer　skin　or　canvas　forming　the　walls　may　be　hauled　into

position；　while　at　the　apex　of　the　roof　further　pulleys　ensure

the　proper　placing　of　the　roofing。　　The　airship　is　able　to　enter

or　leave　from　either　end　according　to　conditions。　　The　material

is　fireproofed　as　a　precautionary　measure；　but　at　the　same　time

the　modern　aerial　bomb　is　able　to　penetrate　the　roofing　without

any　difficulty　and　to　explode　against　the　airship　anchored

within。



The　one　great　objection　to　the　Zeppelin　harbour　is　the　huge

target　it　offers　to　hostile　attack；　which；　in　the　event　of　a

vessel　being　moored　within；　is　inevitably　serious。　　Thus；　for

instance；　upon　the　occasion　of　the　air　raids　conducted　by

Lieutenant　Collet　and　of　Squadron　Commander　Briggs　and　his

colleagues　at　Dusseldorf　and　Friedrichshafen　respectively；

little　difficulty　was　experienced　in　destroying　the　airships

riding　at　anchor。　　The　target　offered　by　the　shed　is　so　extensive

that　it　would　be　scarcely　possible　for　a　flying　enemy　to　miss　it。　

A　bomb　dropped　from　a　reasonable　height；　say　500　feet；　would　be

almost　certain　to　strike　some　part　of　the　building；　and　a

Zeppelin　is　an　easy　vessel　to　destroy。　　The　firing　of　one　balloon

is　sufficient　to　detonate　the　whole；　for　the　simple　reason　that

hydrogen　gas　is　continuously　oozing　through　the　bags　in　which　it

is　contained。　　According　to　a　recent　statement　the　Germans　are

said　to　be　utilising　an　inert　or　non…inflammable　gas；　equal　in

lifting　power　to　hydrogen；　for　the　inflation　of　military　craft；

but　scientific　thought　does　not　entertain　this　statement　with　any

degree　of　seriousness。　　No　gas　as　light　as　hydrogen　and

non…explosive　is　known　to　commerce。



Will　Germany　invade　Great　Britain　by　air？　　This　is　the　absorbing

topic　of　the　momentone　which　has　created　intense　interest　and　a

certain　feeling　of　alarm　among　the　timorous。　　Although　sporadic

raids　are　considered　to　be　possible　and　likely　to　be　carried　out

with　a　varying　measure　of　successsuch　as　that　made　upon　the

British　East　Coasteminent　authorities　ridicule　an　invasion　in

force。　　The　risk　would　be　enormous；　although　there　is　no　doubt

that　Germany；　which　has　always　maintained　that　an　invasion　of

this　character　will　be　made；　will　be　compelled　to　essay　such　a

task；　in　order　to　satisfy　public　opinion；　and　to　justify　official

statements。　　It　is　a　moot　point；　however；　whether　the　invaders

ever　will　succeed　in　making　good　their　escape；　unless　Nature

proves　exceptionally　kind。



The　situation　is　best　summed　up　in　the　unbiassed　report　of

General　George　P。　Scriven；　Chief　Signal　officer　of　the　United

States　Army　to　the　U。S。　Secretary　of　War。　　In　this　report；　which

deals　exhaustively　with　the　history；　construction　and

achievements　of　airships；　such　an　invasion　is　described　as

fantastic　and　impracticable。　　Writing　on　November　10th；　1914；

the　officer　declares　that　〃he　is　not　prepared　to　recommend　the

American　Army　to　take　up　seriously　the　question　of

constructing　dirigibles；　as　they　are　not　worth　their　cost　as

offensive　machines；　while　for　reconnaissance　or　defence　they　are

of　far　less　value　than　aeroplanes。〃　　In　his　words；　〃Dirigibles

are　seemingly　useless　in　defence　against　the　aeroplane　or

gun…fire。〃



In　order　to　be　able　to　make　an　invasion　in　force　upon　Great

Britain's　cities　extremely　favourable　weather　must　prevail；　and

the　treacherous　nature　of　the　weather　conditions　of　the　North　Sea

are　known　fully　well　both　to　British　and　Teuton　navigators。　

Seeing　that　the　majority　of　the　Zeppelin　pilots　are　drawn　from

the　Navy　and　mercantile　marine；　and　thus　are　conversant　with　the

peculiarities　and　characteristics　of　this　stretch　of　salt　water；

it　is　only　logical　to　suppose　that　their　knowledge　will　exert　a

powerful　influence　in　any　such　decision；　the　recommendations

of　the　meteorological　savants　not　withstanding。



When