aeroplanes and dirigibles of war-第24节

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adequate　for　general　reconnoitring；　which　for　the　most　part

entails　short　high　speed　flights；　there　are　occasions　when　the

Staff　demands　more　prolonged　observations　conducted　over　a

greater　radius。　　This　requisition　can　be　met　by　eliminating　the

observer；　whose　duties　in　this　instance　must　be　assumed　by　the

pilot；　and　substituting　in　place　of　the　former；　a　second　fuel

tank　of　sufficient　capacity　for　a　flight　of　four　or　five　hours；

thereby　bringing　the　term　of　action　in　the　air　to　about　6　1/4

hours。　　This　machine　travels　at　a　very　high　speed　and　is

eminently　adapted　to　its　specific　duty；　but　it　is　of　limited

service　for　general　purposes。



The　arming　of　an　aeroplane；　to　enable　it　to　defend　itself　against

hostile　attack　or　to　participate　in　raiding　operations　upon　the

aerial　fleet　of　the　enemy；　appears　to　be　a　simple　task；　but　as　a

matter　of　fact　it　is　an　undertaking　beset　with　difficulties

innumerable。　　This　is　especially　the　case　where　the　aeroplane　is

of　the　tractive　type；　that　is　to　say　where　the　propellers　are

placed　in　the　forefront　of　the　machine　and　in　their　revolution

serve　to　draw　the　machine　forward。　　All　other　considerations　must

necessarily　be　sacrificed　to　the　mounting　of　the　propeller。　

Consequently　it　is　by　no　means　easy　to　allot　a　position　for　the

installation　of　a　gun；　or　if　such　should　be　found　there　is　grave

risk　of　the　angle　of　fire　being　severely　restricted。　　In　fact；　in

many　instances　the　mounting　of　a　gun　is　out　of　the　question：　it

becomes　a　greater　menace　to　the　machine　than　to　the　enemy。



The　French　aeronautical　section　of　the　military　department

devoted　considerable　study　to　this　subject；　but　found　the　problem

almost　insurmount　able。　　Monsieur　Loiseau　met　with　the　greatest

measure　of　success；　and　his　system　is　being　practised　in　the

present　campaign。　　This　principle　is　essentially　adapted　to

tractor　aeroplanes。　　Forward　of　the　pilot　a　special　position　is

reserved　for　the　gunner。　　A　special　mounting　is　provided　towards

the　prow；　and　upon　the　upper　face　of　the　body　of　the　machine。　

The　gun　mounting　is　disposed　in　such　a　manner　that　it　is　able　to

command　a　wide　arc　of　fire　in　the　vertical　plane　over　the　nose　of

the　machine　and　more　particularly　in　the　downward　direction。



The　marksman　is　provided　with　a　special　seat；　but　when　he　comes

into　action　he　has　to　stand　to　manipulate　his　weapon。　　The　lower

part　of　his　body　is　protected　by　a　front　shield　of　steel　plate；　a

fifth　of　an　inch　in　thickness；　while　a　light　railing　extending

upon　either　side　and　behind　enables　the　gunner　to　maintain　his

position　when　the　aeroplane　is　banking　and　climbing。　　The　machine

gun；　of　the　Hotchkiss　type；　is　mounted　upon　a　swivel　attached　to

a　tripod；　while　the　latter　is　built　into　the　bracing　of　the　car；

so　as　to　ensure　a　fairly　steady　gun　platform。



While　the　gun　in　the　hands　of　a　trained　marksman　may　be

manipulated　with　destructive　effect；　the　drawbacks　to　the

arrangement　are　obvious。　　The　gunner　occupies　a　very　exposed

position；　and；　although　the　bullet…proof　shield　serves　to　break

the　effects　of　wind　when　travelling　at　high　speed　which　renders

the　sighting　and　training　of　the　weapon　extremely　difficult；　yet

he　offers　a　conspicuous　target；　more　particularly　when　the　enemy

is　able　to　assume　the　upper　position　in　the　air　as　a　result　of

superior　speed　in　travelling。　　The　gun；　however；　may　be　elevated

to　about　60　degrees；　which　elevation　may　be　accentuated　by　the

inclination　of　the　aeroplane　when　climbing；　while　the　facility

with　which　the　weapon　may　be　moved　through　the　horizontal　plane

is　distinctly　favourable。



But　the　aerial　marksman　suffers　from　one　very　pronounced　defect：

he　has　a　severely　restricted　survey　of　everything　below；　since

his　vision　is　interrupted　by　the　planes。　　The　result　is　that　an

enemy　who　has　lost　ascendancy　of　position　is　comparatively　safe

if　he　is　able　to　fly　immediately　below　his　adversary：　the

mitrailleuse　of　the　latter　cannot　be　trained　upon　him。　　On　the

other　hand　the　enemy；　if　equipped　with　repeating　rifles　or

automatic　pistols；　is　able　to　inflict　appreciable　damage　upon　the

craft　overhead；　the　difficulties　of　firing　vertically　into　the　

air　notwithstanding。



In　the　Vickers　system；　where　the　propeller　is　mounted　behind　the

car；　the　aeroplane　thus　operating　upon　the　pusher　principle；　the

nose　of　the　car　is　occupied　by　the　arm；　which　is　a　rifle　calibre

machine　gun　fitted　upon　a　special　mounting。　　The　prow　is　provided

with　an　embrasure　for　the　weapon　and　the　latter　is　so　installed

as　to　command　an　angle　of　30　degrees　on　all　sides　of　the

longitudinal　axis　of　the　machine　when　in　flight。　　In　this

instance　the　marksman　is　provided　with　complete　protection　on　all

sides；　inasmuch　as　his　position　is　in　the　prow；　where　the　hood　of

the　fo'c's'le　shields　him　from　overhead　attack。　　The　gun　is

protected　by　a　special　shield　which　moves　with　the　gun　barrel。　

This　shield　is　provided　with　mica　windows；　through　which　the

gunner　is　able　to　sight　his　arm；　so　that　he　is　not　inconvenienced

in　any　way　by　the　wind　draught。



One　shortcoming　of　such　methods　of　arming　an　aeroplane　will　be

observed。　　Ahead　firing　only　is　possible；　the　weapon　cannot　be

trained　astern；　while　similarly　the　line　of　fire　on　either

broadside　is　severely　limited。　　This　is　one　reason　why　the

machine…gun　armament　of　aerial　craft　of　the　heavier…than…air　type

has　not　undergone　extensive　development。　　In　many　instances　the

pilot　and　observer　have　expressed　their　preference　for　repeating

high　velocity　rifles　over　any　form　of　fixed　gun　mounting；　and

have　recourse　to　the　latter　only　when　the　conditions　are

extremely　favourable　to　its　effective　employment。



Efforts　are　now　being　made　to　equip　the　military　type　of

aeroplane　with　both　forward　and　astern　firing　guns。　　The　urgency

of　astern　fire　has　been　brought　home　very　vividly。　　Suppose；　for

instance；　two　hostile　aeroplanes；　A　and　B；　are　in　the　air。　　A　has

the　advantage　at　first；　but　B　is　speedier　and　rapidly　overhauls

A。　　During　the　whole　period　of　the　overhauling　movement　the

gun　of　B　can　be　directed　upon　A；　while　the　latter；　owing　to　the

arc　of　training　being　limited　to　c　d　cannot　reply。　　Obviously　in

the　running　fight　it　would　be　to　the　advantage　of　B；　although　the

fleeter　machine；　to　keep　behind　A　（position　1）；　but　the　latter　is

making　towards　its　own　lines。



Under　these　circumstances　A　must　be　headed　off；　so　B　crowds　on

speed　to　consummate　this　end。　　But　in　the　overtaking　process　B

renders　his　gun…fire　ineffective；　inasmuch　as　B　passes　beyond　the

arc　of　his　gun　which　is　represented　by　e　f。　　But　in　so　doing　B

comes　within　the　firing　arc　of　A　（position　9）。　　To　minimise　this

danger　B　ascends　to　a　higher　level　to　obtain　the　paramount

position。



If；　however；　B　were　equipped　with　an　astern　gun　the　aeroplane　A

would　be　within　the　fire　of　B　when　the　forward　gun　of　the　latter

could　not　be　used。　　Similarly　if　A　were　also　fitted　with　an

astern　gun　it　would　be　able　to　attack　its　pursuer　the　whole

time　B　was　to　its　rear　and　in　this　event；　if　its　gun…fire　were

superior；　it　would　be　able　to　keep　the　latter　to　a　safe　distance；

or　compel　B　to　manoeuvre　into　a　superior　position；　which　would

entail　a　certain　loss　of　time。



An　astern　firing　gun　would　be　valuable　to　B　in　another　sense。　

Directly　it　had　passed　A　or　brought　the　latter　within　the　zone　of

its　astern　gun　it　could　maintain　its　fire　at　the　most

advantageous　range；　because　owing　to　its　speed　it　would　be　able

to　dictate　the　distance　over　which　shots　should　be　exchanged　and

if　mounted　with　a　superior　weapon　would　be　able　to　keep　beyond

the　range　of　A's　guns　while　at　the　same　time　it　would　keep　A

within　range　of　its　own　gun　and　consequently　rake　the　latter。　　In

the　interests　of　self…preservation　A　would　be　compelled　to

change　its　course；　in　fact；　B　would　be　able　to　drive　it　in　any

direction　he　desired；　as　he　would　command　A's　movements　by

gun…fire。



The　value　of　combined　ahead　and　astern　firing　has　been

appreciated；　but　there　is　one　difficulty　which　at　the　moment

appears　to　be　insuperable　the　clearance　of　the　propeller。　　At　the

moment　astern…firing；　if　such　it　may　be　called；　is　maintained　by

repeating　rifles；　but　this　armament　is　not　to　be　compared　with

machine…gun　firing；　as　the　latter　with　its　capacity　to　pour　400

to　600　shots　a　minute；　is　far　more　deadly；　particularly　when　the

weapon　is　manipulated　by　a　crack　gunner。



Up　to　the　present　the　offensive　armament　of　aeroplanes　has　been

confined　to　light　machine　guns　such　as　the　Hotchkiss；　Berthier；

Schwartlose；　and　Maxim　weapons。　　So　far　as　the　arming　of

aeroplanes　is　concerned　the　indispensable　condition　is　light

weight。　　With　airships　this　factor　is　not　so　vital；　the　result

being　that　some　dirigibles　are　mounted　with　guns；　throwing　one

pound　bursting　shells；　fitted　either　with　delay　action　or

percussion　fuses；　the　former　for　preference。　　These　shells　are

given　a　wi