flying machines-第17部分

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ends　of　the　main　planes　so　that　they　may　swing　outward；

the　aviator　controlling　both　tips　through　one　lever

so　that　as　one　tip　is　extended　the　other　is　retracted。



〃The　elastic　wing　pinions　of　a　bird　bend　easily　before

the　wind；　permitting　the　gusts　to　glance　off；　but　presenting

always　an　even　and　efficient　curvature　to　the

steady　currents　of　the　air。〃



High　Winds　Threaten　Stability。



To　ensure　perfect　stability；　without　control；　either　human

or　automatic；　it　is　asserted　that　the　aeroplane　must

move　faster　than　the　wind　is　blowing。　So　long　as　the

wind　is　blowing　at　the　rate　of　30　miles　an　hour；　and　the

machine　is　traveling　40　or　more；　there　will　be　little　trouble

as　regards　equilibrium　so　far　as　wind　disturbance

goes；　provided　the　wind　blows　evenly　and　does　not　come

in　gusts　or　eddying　currents。　But　when　conditions　are

reversedwhen　the　machine　travels　only　30　miles　an

hour　and　the　wind　blows　at　the　rate　of　50；　look　out　for

loss　of　equilibrium。



One　of　the　main　reasons　for　this　is　that　high　winds

are　rarely　steady；　they　seldom　blow　for　any　length　of

time　at　the　same　speed。　They　are　usually　〃gusty；〃　the

gusts　being　a　momentary　movement　at　a　higher　speed。

Tornadic　gusts　are　also　formed　by　the　meeting　of　two

opposing　currents；　causing　a　whirling　motion；　which

makes　stability　uncertain。　Besides；　it　is　not　unusual

for　wind　of　high　speed　to　suddenly　change　its　direction

without　warning。



Trouble　With　Vertical　Columns。



Vertical　currentscolumns　of　ascending　airare

frequently　encountered　in　unexpected　places　and　have　more

or　less　tendency；　according　to　their　strength；　to　make

it　difficult　to　keep　the　machine　within　a　reasonable

distance　from　the　ground。



These　vertical　currents　are　most　generally　noticeable

in　the　vicinity　of　steep　cliffs；　or　deep　ravines。　In　such

instances　they　are　usually　of　considerable　strength；　being

caused　by　the　deflection　of　strong　winds　blowing

against　the　face　of　the　cliffs。　This　deflection　exerts　a

back　pressure　which　is　felt　quite　a　distance　away　from

the　point　of　origin；　so　that　the　vertical　current　exerts　an

influence　in　forcing　the　machine　upward　long　before　the

cliff　is　reached。







CHAPTER　XV。



THE　ELEMENT　OF　DANGER。



That　there　is　an　element　of　danger　in　aviation　is

undeniable；　but　it　is　nowhere　so　great　as　the　public

imagines。　Men　are　killed　and　injured　in　the　operation

of　flying　machines　just　as　they　are　killed　and　injured　in

the　operation　of　railways。　Considering　the　character　of

aviation　the　percentage　of　casualties　is　surprisingly

small。



This　is　because　the　results　following　a　collapse　in　the

air　are　very　much　different　from　what　might　be　imagined。

Instead　of　dropping　to　the　ground　like　a　bullet　an

aeroplane；　under　ordinary　conditions　will；　when　anything

goes　wrong；　sail　gently　downward　like　a　parachute；

particularly　if　the　operator　is　cool…headed　and　nervy　enough

to　so　manipulate　the　apparatus　as　to　preserve　its　equilibrium

and　keep　the　machine　on　an　even　keel。



Two　Fields　of　Safety。



At　least　one　prominent　aviator　has　declared　that　there

are　two　fields　of　safetyone　close　to　the　ground；　and

the　other　well　up　in　the　air。　In　the　first…named　the　fall

will　be　a　slight　one　with　little　chance　of　the　operator

being　seriously　hurt。　From　the　field　of　high　altitude　the

the　descent　will　be　gradual；　as　a　rule；　the　planes　of　the

machine　serving　to　break　the　force　of　the　fall。　With　a

cool…headed　operator　in　control　the　aeroplane　may　be

even　guided　at　an　angle　（about　1　to　8）　in　its　descent　so

as　to　touch　the　ground　with　a　gliding　motion　and　with

a　minimum　of　impact。



Such　an　experience；　of　course；　is　far　from　pleasant；

but　it　is　by　no　means　so　dangerous　as　might　appear。

There　is　more　real　danger　in　falling　from　an　elevation

of　75　or　100　feet　than　there　is　from　1；000　feet；　as　in　the

former　case　there　is　no　chance　for　the　machine　to　serve　as

a　parachuteits　contact　with　the　ground　comes　too

quickly。



Lesson　in　Recent　Accidents。



Among　the　more　recent　fatalities　in　aviation　are　the

deaths　of　Antonio　Fernandez　and　Leon　Delagrange。　The

former　was　thrown　to　the　ground　by　a　sudden　stoppage

of　his　motor；　the　entire　machine　seeming　to　collapse。

It　is　evident　there　were　radical　defects；　not　only　in　the

motor；　but　in　the　aeroplane　framework　as　well。　At　the

time　of　the　stoppage　it　is　estimated　that　Fernandez　was

up　about　1；500　feet；　but　the　machine　got　no　opportunity

to　exert　a　parachute　effect；　as　it　broke　up　immediately。

This　would　indicate　a　fatal　weakness　in　the　structure

which；　under　proper　testing；　could　probably　have　been

detected　before　it　was　used　in　flight。



It　is　hard　to　say　it；　but　Delagrange　appears　to　have

been　culpable　to　great　degree　in　overloading　his　machine

with　a　motor　equipment　much　heavier　than　it　was

designed　to　sustain。　He　was　65　feet　up　in　the　air　when

the　collapse　occurred；　resulting　in　his　death。　As　in　the

case　of　Fernandez　common…sense　precaution　would

doubtless　have　prevented　the　fatality。



Aviation　Not　Extra　Hazardous。



All　told　there　have　been；　up　to　the　time　of　this　writing

（April；　1910）；　just　five　fatalities　in　the　history　of　power…

driven　aviation。　This　is　surprisingly　low　when　the　nature

of　the　experiments；　and　the　fact　that　most　of　the

operators　were　far　from　having　extended　experience；　is

taken　into　consideration。　Men　like　the　Wrights；　Curtiss；

Bleriot；　Farman；　Paulhan　and　others；　are　now　experts；

but　there　was　a　time；　and　it　was　not　long　ago；　when　they

were　unskilled。　That　they；　with　numerous　others　less

widely　known；　should　have　come　safely　through　their

many　experiments　would　seem　to　disprove　the　prevailing

idea　that　aviation　is　an　extra　hazardous　pursuit。



In　the　hands　of　careful；　quick…witted；　nervy　men　the

sailing　of　an　airship　should　be　no　more　hazardous　than

the　sailing　of　a　yacht。　A　vessel　captain　with　common

sense　will　not　go　to　sea　in　a　storm；　or　navigate　a　weak；

unseaworthy　craft。　Neither　should　an　aviator　attempt

to　sail　when　the　wind　is　high　and　gusty；　nor　with　a　machine

which　has　not　been　thoroughly　tested　and　found　to

be　strong　and　safe。



Safer　Than　Railroading。



Statistics　show　that　some　12；000　people　are　killed　and

72；000　injured　every　year　on　the　railroads　of　the　United

States。　Come　to　think　it　over　it　is　small　wonder　that

the　list　of　fatalities　is　so　large。　Trains　are　run　at　high

speeds；　dashing　over　crossings　at　which　collisions　are

liable　to　occur；　and　over　bridges　which　often　collapse

or　are　swept　away　by　floods。　Still；　while　the　number　of

casualties　is　large；　the　actual　percentage　is　small　considering

the　immense　number　of　people　involved。



It　is　so　in　aviation。　The　number　of　casualties　is　remarkably

small　in　comparison　with　the　number　of　flights

made。　In　the　hands　of　competent　men　the　sailing　of　an

airship　should　be；　and　is；　freer　from　risk　of　accident　than

the　running　of　a　railway　train。　There　are　no　rails　to

spread　or　break；　no　bridges　to　collapse；　no　crossings　at

which　collisions　may　occur；　no　chance　for　some　sleepy

or　overworked　employee　to　misunderstand　the　dispatcher's

orders　and　cause　a　wreck。



Two　Main　Causes　of　Trouble。



The　two　main　causes　of　trouble　in　an　airship　leading

to　disaster　may　be　attributed　to　the　stoppage　of　the

motor；　and　the　aviator　becoming　rattled　so　that　he　loses

control　of　his　machine。　Modern　ingenuity　is　fast　developing

motors　that　almost　daily　become　more　and　more

reliable；　and　experience　is　making　aviators　more　and

more　self…confident　in　their　ability　to　act　wisely　and

promptly　in　cases　of　emergency。　Besides　this　a　satisfactory

system　of　automatic　control　is　in　a　fair　way

of　being　perfected。



Occasionally　even　the　most　experienced　and　competent

of　men　in　all　callings　become　careless　and　by　foolish

action　invite　disaster。　This　is　true　of　aviators　the　same

as　it　is　of　railroaders；　men　who　work　in　dynamite　mills；

etc。　But　in　nearly　every　instance　the　responsibility　rests

with　the　individual；　not　with　the　system。　There　are

some　men　unfitted　by　nature　for　aviation；　just　as　there

are　others　unfitted　to　be　railway　engineers。







CHAPTER　XVI。



RADICAL　CHANGES　BEING　MADE。



Changes；　many　of　them　extremely　radical　in　their　nature；

are　continually　being　made　by　prominent　aviators；

and　particularly　those　who　have　won　the　greatest　amount

of　success。　Wonderful　as　the　results　have　been　few　of

the　aviators　are　really　satisfied。　Their　successes　have

merely　spurred　them　on　to　new　endeavors；　the　ultimate

end　being　the　development　of　an　absolutely　perfect　aircraft。



Among　the　men　who　have　been　thus　experimenting

are　the　Wright　Brothers；　who　last　year　（1909）　brought

out　a　craft　totally　different　as　regards　proportions　and

weight　from　the　one　used　the　preceding　year。　One

marked　result　was　a　gain　of　about　3　1/2　miles　an　hour　in

speed。



Dimensions　of　1908　Machine。



The　1908　model　aeroplane　was　40　by　29　feet　over　all。

The　carrying　surfaces；　that　is；　the　two　aerocurves；　were

40　by　6　feet；　having　a　parabolical　curve　of　one　in　twelve。

With　about　70　square　feet　of　surface　in　the　rudders；　the

total　surface　given　was　about　550　square　feet。　The

engine；　which　is　the　invention　of　the　Wright　brothers；

weighed；　approximately；　200　pounds；　and　gave　about　25

horsepower　at　1；400　revolutions　per　minute。　The　total

weight　of　the　aeroplane；　exclusive　of　passenger；　but

inclusive　of　engine；　was　about　1；150　pounds。　This　result

showed　a　lift　of　a　fraction　over　2　1/4　pounds　to　the　square

foot　of　carrying　surface。　The　speed　desired　was　40

miles　an　hour；　but　the　machine　was　found　to　make　only

a　scant　39　miles　an　hour。　The　upright　struts　were

about　7/8…inch　thick；　the　skids；　2　1/2　by　1　1/4　inches　thick。



Dimensions　of　1909　Machine。



The　1909　aeroplane　was　built　primarily　for　greater

speed；　and　relatively　heavier；　to　be　less