flying machines-第3节

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many　and；　like　Pilcher；　was　the　victim　of　a　distorted

apparatus。　Probably　one　of　the　joints　of　the　struts

gave　way；　the　upper　surface　blew　back　and　Lilienthal；

who　was　well　forward　on　the　lower　surface；　was　pitched

headlong　to　destruction。



Experiments　by　the　Writer。



In　1896；　assisted　by　Mr。　Herring　and　Mr。　Avery；　I

experimented　with　several　full　sized　gliding　machines；

carrying　a　man。　The　first　was　a　Lilienthal　monoplane

which　was　deemed　so　cranky　that　it　was　discarded　after

making　about　one　hundred　glides；　six　weeks　before

Lilienthal's　accident。　The　second　was　known　as　the

multiple　winged　machine　and　finally　developed　into　five

pairs　of　pivoted　wings；　trussed　together　at　the　front　and

one　pair　in　the　rear。　It　glided　at　angles　of　descent　of

10　or　11　degrees　or　of　one　in　five；　and　this　was　deemed

too　steep。　Then　Mr。　Herring　and　myself　made　computations

to　analyze　the　resistances。　We　attributed　much

of　them　to　the　five　front　spars　of　the　wings　and　on　a

sheet　of　cross…barred　paper　I　at　once　drew　the　design　for

a　new　three…decked　machine　to　be　built　by　Mr。　Herring。



Being　a　builder　of　bridges；　I　trussed　these　surfaces

together；　in　order　to　obtain　strength　and　stiffness。　When

tested　in　gliding　flight　the　lower　surface　was　found　too

near　the　ground。　It　was　taken　off　and　the　remaining

apparatus　now　consisted　of　two　surfaces　connected　together

by　a　girder　composed　of　vertical　posts　and　diagonal

ties；　specifically　known　as　a　〃Pratt　truss。〃　Then

Mr。　Herring　and　Mr。　Avery　together　devised　and　put

on　an　elastic　attachment　to　the　tail。　This　machine

proved　a　success；　it　being　safe　and　manageable。　Over

700　glides　were　made　with　it　at　angles　of　descent　of　8

to　10　degrees；　or　one　in　six　to　one　in　seven。



First　Proposed　by　Wenham。



The　elastic　tail　attachment　and　the　trussing　of　the

connecting　frame　of　the　superposed　wings　were　the　only

novelties　in　this　machine；　for　the　superposing　of　the

surfaces　had　first　been　proposed　by　Wenham；　but　in

accordance　with　the　popular　perception；　which　bestows

all　the　credit　upon　the　man　who　adds　the　last　touch

making　for　success　to　the　labors　of　his　predecessors；　the

machine　has　since　been　known　by　many　persons　as　the

〃Chanute　type〃　of　gliders；　much　to　my　personal　gratification。



It　has　since　been　improved　in　many　ways。　Wright

Brothers；　disregarding　the　fashion　which　prevails　among

birds；　have　placed　the　tail　in　front　of　their　apparatus　and

called　it　a　front　rudder；　besides　placing　the　operator　in

horizontal　position　instead　of　upright；　as　I　did；　and　also

providing　a　method　of　warping　the　wings　to　preserve

equilibrium。　Farman　and　Delagrange；　under　the　very

able　guidance　and　constructive　work　of　Voisin　brothers；

then　substituted　many　details；　including　a　box　tail　for

the　dart…like　tail　which　I　used。　This　may　have　increased

the　resistance；　but　it　adds　to　the　steadiness。　Now　the

tendency　in　France　seems　to　be　to　go　back　to　the　monoplane。



Monoplane　Idea　Wrong。



The　advocates　of　the　single　supporting　surface　are

probably　mistaken。　It　is　true　that　a　single　surface

shows　a　greater　lift　per　square　foot　than　superposed

surfaces　for　a　given　speed；　but　the　increased　weight　due

to　leverage　more　than　counterbalances　this　advantage　by

requiring　heavy　spars　and　some　guys。　I　believe　that


the　future　aeroplane　dynamic　flier　will　consist　of　superposed

surfaces；　and；　now　that　it　has　been　found　that　by

imbedding　suitably　shaped　spars　in　the　cloth　the　head

resistance　may　be　much　diminished；　I　see　few　objections

to　superposing　three；　four　or　even　five　surfaces　properly

trussed；　and　thus　obtaining　a　compact；　handy；　manageable

and　comparatively　light　apparatus。＇2＇





＇2＇　Aeronautics。







CHAPTER　II。



THEORY；　DEVELOPMENT；　AND　USE。





While　every　craft　that　navigates　the　air　is　an　airship；

all　airships　are　not　flying　machines。　The　balloon；

for　instance；　is　an　airship；　but　it　is　not　what　is　known

among　aviators　as　a　flying　machine。　This　latter　term

is　properly　used　only　in　referring　to　heavier…than…air

machines　which　have　no　gas…bag　lifting　devices；　and　are　made　to

really　fly　by　the　application　of　engine　propulsion。



Mechanical　Birds。



All　successful　flying　machinesand　there　are　a　number

of　themare　based　on　bird　action。　The　various

designers　have　studied　bird　flight　and　soaring；　mastered

its　technique　as　devised　by　Nature；　and　the　modern　flying

machine　is　the　result。　On　an　exaggerated；　enlarged

scale　the　machines　which　are　now　navigating　the　air

are　nothing　more　nor　less　than　mechanical　birds。



Origin　of　the　Aeroplane。



Octave　Chanute；　of　Chicago；　may　well　be　called　〃the

developer　of　the　flying　machine。〃　Leaving　balloons　and

various　forms　of　gas…bags　out　of　consideration；　other

experimenters；　notably　Langley　and　Lilienthal；　antedated

him　in　attempting　the　navigation　of　the　air　on

aeroplanes；　or　flying　machines；　but　none　of　them　were

wholly　successful；　and　it　remained　for　Chanute　to　demonstrate

the　practicability　of　what　was　then　called　the

gliding　machine。　This　term　was　adopted　because　the

apparatus　was；　as　the　name　implies；　simply　a　gliding

machine；　being　without　motor　propulsion；　and　intended

solely　to　solve　the　problem　of　the　best　form　of

construction。　The　biplane；　used　by　Chanute　in　1896；　is

still　the　basis　of　most　successful　flying　machines；　the

only　radical　difference　being　that　motors；　rudders；　etc。；

have　been　added。



Character　of　Chanute's　Experiments。



It　was　the　privilege　of　the　author　of　this　book　to　be

Mr。　Chanute's　guest　at　Millers；　Indiana；　in　1896；　when；

in　collaboration　with　Messrs。　Herring　and　Avery；　he　was

conducting　the　series　of　experiments　which　have　since

made　possible　the　construction　of　the　modern　flying

machine　which　such　successful　aviators　as　the　Wright

brothers　and　others　are　now　using。　It　was　a　wild

country；　much　frequented　by　eagles；　hawks；　and　similar

birds。　The　enthusiastic　trio；　Chanute；　Herring　and

Avery；　would　watch　for　hours　the　evolutions　of　some

big　bird　in　the　air；　agreeing　in　the　end　on　the　verdict；

〃When　we　master　the　principle　of　that　bird's　soaring

without　wing　action；　we　will　have　come　close　to　solving

the　problem　of　the　flying　machine。〃



Aeroplanes　of　various　forms　were　constructed　by　Mr。

Chanute　with　the　assistance　of　Messrs。　Herring　and

Avery　until；　at　the　time　of　the　writer's　visit；　they　had

settled　upon　the　biplane；　or　two…surface　machine。　Mr。

Herring　later　equipped　this　with　a　rudder；　and　made

other　additions；　but　the　general　idea　is　still　the　basis　of

the　Wright；　Curtiss；　and　other　machines　in　which；　by

the　aid　of　gasolene　motors；　long　flights　have　been　made。



Developments　by　the　Wrights。



In　1900　the　Wright　brothers；　William　and　Orville；　who　were　then

in　the　bicycle　business　in　Dayton；　Ohio；

became　interested　in　Chanute's　experiments　and

communicated　with　him。　The　result　was　that　the　Wrights

took　up　Chanute's　ideas　and　developed　them　further；

making　many　additions　of　their　own；　one　of　which　was

the　placing　of　a　rudder　in　front；　and　the　location　of　the

operator　horizontally　on　the　machine；　thus　diminishing

by　four…fifths　the　wind　resistance　of　the　man's　body。

For　three　years　the　Wrights　experimented　with　the

glider　before　venturing　to　add　a　motor；　which　was　not

done　until　they　had　thoroughly　mastered　the　control　of

their　movements　in　the　air。



Limits　of　the　Flying　Machine。



In　the　opinion　of　competent　experts　it　is　idle　to　look

for　a　commercial　future　for　the　flying　machine。　There

is；　and　always　will　be；　a　limit　to　its　carrying　capacity

which　will　prohibit　its　employment　for　passenger　or

freight　purposes　in　a　wholesale　or　general　way。　There

are　some；　of　course；　who　will　argue　that　because　a

machine　will　carry　two　people　another　may　be　constructed

that　will　carry　a　dozen；　but　those　who　make

this　contention　do　not　understand　the　theory　of　weight

sustentation　in　the　air；　or　that　the　greater　the　load　the

greater　must　be　the　lifting　power　（motors　and　plane

surface）；　and　that　there　is　a　limit　to　theseas　will　be

explained　later　onbeyond　which　the　aviator　cannot　go。



Some　Practical　Uses。



At　the　same　time　there　are　fields　in　which　the　flying

machine　may　be　used　to　great　advantage。　These　are：



SportsFlying　machine　races　or　flights　will　always

be　popular　by　reason　of　the　element　of　danger。　It　is

a　strange；　but　nevertheless　a　true　proposition；　that　it　is

this　element　which　adds　zest　to　all　sporting　events。



ScientificFor　exploration　of　otherwise　inaccessible

regions　such　as　deserts；　mountain　tops；　etc。



ReconnoiteringIn　time　of　war　flying　machines　may

be　used　to　advantage　to　spy　out　an　enemy's　encampment；

ascertain　its　defenses；　etc。







CHAPTER　III。



MECHANICAL　BIRD　ACTION



In　order　to　understand　the　theory　of　the　modern　flying

machine　one　must　also　understand　bird　action　and　wind

action。　In　thi