aeroplanes-第8章

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not　a　propeller；　by　any　means　comparable　to　the

kind　mounted　on　a　shaft；　and　revoluble。



How　much　more　efficient　are　the　spirally…formed

blades　of　the　propeller　than　any　wing　or　fin　movement；

in　air　or　sea。　There　is　no　comparison　between

the　two　forms　in　utility　or　value。



Again；　the　connecting　points　of　the　arms　and

legs　with　the　trunk　of　a　human　body　afford　the

most　perfect　types　of　universal　joints　which　nature

has　produced。　The　man…made　universal

joint　has　a　wider　range　of　movement；　possesses

greater　strength；　and　is　more　perfect　mechanically。

A　universal　joint　is　a　piece　of　mechanism

between　two　elements；　which　enables　them　to　be

turned；　or　moved；　at　any　angle　relative　to　each

other。



But　why　multiply　these　instances。　Like　samples

will　be　found　on　every　hand；　and　in　all　directions；

and　man；　the　greatest　of　all　of　nature's

products；　while　imperfect　in　himself；　is　improving

and　adapting　the　things　he　sees　about　him。



WHY　SPECIALLY…DESIGNED　FORMS　IMPROVE　NATURAL

STRUCTURES。The　reason　for　this　is；　primarily；

that　the　inventor　must　design　the　article

for　its　special　work；　and　in　doing　so　makes　it　better

adapted　to　do　that　particular　thing。　The

hands　and　fingers　can　do　a　multiplicity　of　things；

but　it　cannot　do　any　particular　work　with　the　facility

or　the　degree　of　perfection　that　is　possible

with　the　machine　made　for　that　purpose。



The　hands　and　fingers　will　bind　a　sheaf　of

wheat；　but　it　cannot　compete　with　the　special　machine

made　for　that　purpose。　On　the　other　hand

the　binder　has　no　capacity　to　do　anything　else　than

what　it　was　specially　made　for。



In　applying　the　same　sort　of　reasoning　to　the

building　of　flying　machines　we　must　be　led　to　the

conclusion　that　the　inventor　can；　and　will；　eventually；

bring　out　a　form　which　is　as　far　superior　to

the　form　which　nature　has　taught　us　to　use　as

the　wonderful　machines　we　see　all　about　us　are

superior　to　carry　out　the　special　work　they　were

designed　to　do。



On　land；　man　has　shown　this　superiority　over

matter；　and　so　on　the　sea。　Singularly；　the　submarines；

which　go　beneath　the　sea；　are　very　far

from　that　perfected　state　which　have　been　attained

by　vessels　sailing　on　the　surface；　and　while

the　means　of　transportation　on　land　are　arriving

at　points　where　the　developments　are　swift　and

remarkable；　the　space　above　the　earth　has　not　yet

been　conquered；　but　is　going　through　that　same

period　of　development　which　precedes　the　production

of　the　true　form　itself。



MECHANISM　DEVOID　OF　INTELLIGENCE。The　great

error；　however；　in　seeking　to　copy　nature's　form

in　a　flying　machine　is；　that　we　cannot　invest　the

mechanism　with　that　which　the　bird　has；　namely；

a　guiding　intelligence　to　direct　it　instinctively；　as

the　flying　creature　does。



A　MACHINE　MUST　HAVE　A　SUBSTITUTE　FOR　INTELLIGENCE。

Such　being　the　case　it　must　be　endowed

with　something　which　is　a　substitute。　A

bird　is　a　supple；　pliant　organism；　a　machine　is　a

rigid　structure。　One　is　capable　of　being　directed

by　a　mind　which　is　a　part　of　the　thing　itself；　while

the　other　must　depend　on　an　intelligence　which　is

separate　from　it；　and　not　responsive　in　feeling　or

movement。



For　the　foregoing　reasons　success　can　never

be　attained　until　some　structural　form　is　devised

which　will　consider　the　flying　machine　independently

of　the　prototypes　pointed　out　as　the　correct

things　to　follow。　It　does　not；　necessarily；　have　to

be　unlike　the　bird　form；　but　we　do　know　that　the

present　structures　have　been　made　and　insisted

upon　blindly；　because　of　this　wrong　insistence　on

forms。



STUDY　OF　BIRD　FLIGHT　USELESS。The　study　of

the　flight　of　birds　has　never　been　of　any　special

value　to　the　art。　Volumes　have　been　written　on

the　subject。　The　Seventh　Duke　of　Argyle；　and

later；　Pettigrew；　an　Englishman；　contributed　a

vast　amount　of　written　matter　on　the　subject　of

bird　flight；　in　which　it　was　sought　to　show　that

soaring　birds　did　not　exert　any　power　in　flying。



Writers　and　experimenters　do　not　agree　on　the

question　of　the　propulsive　power；　or　on　the　form

or　shape　of　the　wing　which　is　most　effective；　or

in　the　matter　of　the　relation　of　surface　to　weight；

nor　do　they　agree　in　any　particular　as　to　the　effect

and　action　of　matter　in　the　soaring　principle。



Only　a　small　percentage　of　flying　creatures　use

motionless　wings　as　in　soaring。　By　far；　the

greater　majority　use　beating　wings；　a　method　of

translation　in　air　which　has　not　met　with　success

in　any　attempts　on　the　part　of　the　inventor。



Nevertheless；　experimenting　has　proceeded　on

lines　which　seek　to　recognize　nature's　form　only；

while　avoiding　the　best　known　and　most　persistent

type。



SHAPE　OF　SUPPORTING　SURFACES。When　we　examine

the　prevailing　type　of　supporting　surfaces

we　cannot　fail　to　be　impressed　with　one　feature；

namely；　the　determination　to　insist　on　a　broad

spread　of　plane　surface；　in　imitation　of　the　bird

with　outstretched　wings。



THE　TROUBLE　ARISING　FROM　OUTSTRETCHED

WINGS。This　form　of　construction　is　what　brings

all　the　troubles　in　its　train。　The　literature　on

aviation　is　full　of　arguments　on　this　subject；　all

declaring　that　a　wide　spread　is　essential；　because；

birds　fly　that　way。



These　assertions　are　made　notwithstanding　the

fact　that　only　a　few　years　ago；　in　the　great　exhibit

of　aeroplanes　in　Paris；　many　unique　forms　of　machines

were　shown；　all　of　them　capable　of　flying；

as　proven　by　numerous　experiments；　and　among

them　were　a　half　dozen　types　whose　length　fore

and　aft　were　much　greater　than　transversely；　and

it　was　particularly　noted　that　they　had　most　wonderful

stability。



DENSITY　OF　THE　ATMOSPHERE。Experts　declare

that　the　density　of　the　atmosphere　varies　throughout；

that　it　has　spots　here　and　there　which　are；

apparently；　like　holes；　so　that　one　side　or　the

other　of　the　machine　will；　unaccountably；　tilt；　and

sometimes　the　entire　machine　will　suddenly　drop

for　many　feet；　while　in　flight。



ELASTICITY　OF　THE　AIR。Air　is　the　most　elastic

substance　known。　The　particles　constituting　it

are　constantly　in　motion。　When　heat　or　cold　penetrate

the　mass　it　does　so；　in　a　general　way；　so　as

to　permeate　the　entire　body；　but　the　conductivity

of　the　atmospheric　gases　is　such　that　the　heat

does　not　reach　all　parts　at　the　same　time。



AIR　HOLES。The　result　is　that　varying　strata

of　heat　and　cold　seem　to　be　superposed；　and　also

distributed　along　the　route　taken　by　a　machine；

causing　air　currents　which　vary　in　direction　and

intensity。　When；　therefore；　a　rapidly…moving

machine　passes　through　an　atmosphere　so　disturbed；

the　surfaces　of　the　planes　strike　a　mass　of

air　moving；　we　may　say；　first　toward　the　plane；

and　the　next　instant　the　current　is　reversed；　and

the　machine　drops；　because　its　support　is　temporarily

gone；　and　the　aviator　experiences　the　sensation

of　going　into　a　〃hole。〃



RESPONSIBILITY　FOR　ACCIDENTS。These　so…called

〃holes〃　are　responsible　for　many　accidents。　The

outstretched　wings；　many　of　them　over　forty　feet

from　tip　to　tip；　offer　opportunities　for　a　tilt　at　one

end　or　the　other；　which　has　sent　so　many　machines

to　destruction。



The　high　center　of　gravity　in　all　machines　makes

the　weight　useless　to　counterbalance　the　rising

end　or　to　hold　up　the　depressed　wing。



All　aviators　agree　that　these　unequal　areas　of

density　extend　over　small　spaces；　and　it　is；　therefore；

obvious　that　a　machine　which　is　of　such　a

structure　that　it　moves　through　the　air　broadside

on；　will　be　more　liable　to　meet　these　inequalities

than　one　which　is　narrow　and　does　not　take　in　such

a　wide　path。



Why；　therefore；　persist　in　making　a　form　which；

by　its　very　nature；　invites　danger？　Because　birds

fly　that　way！



THE　TURNING　MOVEMENT。This　structural　arrangement

accentuates　the　difficulty　when　the　machine

turns。　The　air　pressure　against　the　wing

surface　is　dependent　on　the　speed。　The　broad

ou