be¡¡advantageously¡¡used¡¡as¡¡a¡¡model¡¡aeroplane£»¡¡but
in¡¡that¡¡case¡¡the¡¡broad¡¡end¡¡should¡¡be¡¡foremost¡£
_Fig¡£¡¡86¡£¡¡The¡¡Deltoid¡¡Racer¡£_
Fig¡£¡¡86¡¡shows¡¡the¡¡deltoid¡¡glider£»¡¡or¡¡aeroplane£»
with¡¡three¡¡cross¡¡braces£»¡¡A£»¡¡B£»¡¡C£»¡¡in¡¡the¡¡two¡¡forward
braces¡¡of¡¡which¡¡are¡¡journaled¡¡the¡¡propeller
shaft¡¡D£»¡¡so¡¡that¡¡the¡¡propeller¡¡E¡¡is¡¡at¡¡the¡¡broad
end¡¡of¡¡the¡¡glider¡£
A¡¡short¡¡stem¡¡F¡¡through¡¡the¡¡rear¡¡brace¡¡C£»¡¡provided
with¡¡a¡¡crank£»¡¡has¡¡its¡¡inner¡¡end¡¡connected
with¡¡the¡¡rear¡¡end¡¡of¡¡the¡¡shaft¡¡D¡¡by¡¡a¡¡rubber¡¡band
G£»¡¡by¡¡which¡¡the¡¡propeller¡¡is¡¡driven¡£
A¡¡tail¡¡may¡¡be¡¡attached¡¡to¡¡the¡¡rear¡¡end£»¡¡or¡¡at
the¡¡apex¡¡of¡¡the¡¡planes£»¡¡so¡¡it¡¡can¡¡be¡¡set¡¡for¡¡the
purpose¡¡of¡¡directing¡¡the¡¡angle¡¡of¡¡flight£»¡¡but¡¡it¡¡will
be¡¡found¡¡that¡¡this¡¡form¡¡has¡¡remarkable¡¡stability
in¡¡flight£»¡¡and¡¡will¡¡move¡¡forwardly¡¡in¡¡a¡¡straight
line£»¡¡always¡¡making¡¡a¡¡graceful¡¡downward¡¡movement
when¡¡the¡¡power¡¡is¡¡exhausted¡£
It¡¡seems¡¡to¡¡be¡¡a¡¡form¡¡which¡¡has¡¡equal¡¡stabilizing
powers¡¡whether¡¡at¡¡slow¡¡or¡¡at¡¡high¡¡speeds£»
thus¡¡differing¡¡essentially¡¡from¡¡many¡¡forms¡¡which
require¡¡a¡¡certain¡¡speed¡¡in¡¡order¡¡to¡¡get¡¡the¡¡best
results¡£
RACING¡¡MODELS¡£Here¡¡and¡¡in¡¡England¡¡many
racing¡¡models¡¡have¡¡been¡¡made£»¡¡generally¡¡of¡¡the
A¡shaped¡¡type£»¡¡which¡¡will¡¡be¡¡explained¡¡hereinafter¡£
Such¡¡models¡¡are¡¡also¡¡strong£»¡¡and¡¡able¡¡to
withstand¡¡the¡¡torsional¡¡strain¡¡required¡¡by¡¡the
rubber¡¡which¡¡is¡¡used¡¡for¡¡exerting¡¡the¡¡power¡£
It¡¡is¡¡unfortunate¡¡that¡¡there¡¡is¡¡not¡¡some¡¡type¡¡of
cheap¡¡motor¡¡which¡¡is¡¡light£»¡¡and¡¡adapted¡¡to¡¡run
for¡¡several¡¡minutes£»¡¡which¡¡would¡¡be¡¡of¡¡great¡¡value
in¡¡work¡¡of¡¡this¡¡kind£»¡¡but¡¡in¡¡the¡¡absence¡¡of¡¡such
mechanism¡¡rubber¡¡bands¡¡are¡¡found¡¡to¡¡be¡¡most
serviceable£»¡¡giving¡¡better¡¡results¡¡than¡¡springs¡¡or
bows£»¡¡since¡¡the¡¡latter¡¡are¡¡both¡¡too¡¡heavy¡¡to¡¡be
available£»¡¡in¡¡proportion¡¡to¡¡the¡¡amount¡¡of¡¡power
developed¡£
Unlike¡¡the¡¡large¡¡aeroplanes£»¡¡the¡¡supporting
surfaces£»¡¡in¡¡the¡¡models£»¡¡are¡¡at¡¡the¡¡rear¡¡end¡¡of
the¡¡frames£»¡¡the¡¡pointed¡¡ends¡¡being¡¡in¡¡front¡£
_Fig¡£¡¡87¡£¡¡A¡Shaped¡¡Racing¡¡Glider¡£_
Fig¡£¡¡87¡¡shows¡¡the¡¡general¡¡design¡¡of¡¡the¡¡A¡
shaped¡¡gliding¡¡plane¡¡or¡¡aeroplane¡£¡¡This¡¡is¡¡composed
of¡¡main¡¡frame¡¡pieces¡¡A£»¡¡A£»¡¡running¡¡fore
and¡¡aft£»¡¡joined¡¡at¡¡their¡¡rear¡¡ends¡¡by¡¡a¡¡cross¡¡bar
B£»¡¡the¡¡ends¡¡of¡¡which¡¡project¡¡out¡¡slightly¡¡beyond
their¡¡juncture¡¡with¡¡the¡¡side¡¡bars¡¡A£»¡¡A¡£¡¡These
projecting¡¡ends¡¡have¡¡holes¡¡drilled¡¡therein¡¡to¡¡receive
the¡¡shafts¡¡a£»¡¡a£»¡¡of¡¡the¡¡propeller¡¡D£»¡¡D¡£
A¡¡main¡¡plane¡¡E¡¡is¡¡mounted¡¡transversely¡¡across
this¡¡frame¡¡at¡¡its¡¡rear¡¡end£»¡¡while¡¡at¡¡its¡¡forward
end¡¡is¡¡a¡¡small¡¡plane£»¡¡called¡¡the¡¡elevator¡£¡¡The
pointed¡¡end¡¡of¡¡the¡¡frame¡¡has¡¡on¡¡each¡¡side¡¡a¡¡turnbuckle
G£»¡¡for¡¡the¡¡purpose¡¡of¡¡winding¡¡up¡¡the¡¡shaft£»
and¡¡thus¡¡twisting¡¡the¡¡propeller£»¡¡although¡¡this¡¡is
usually¡¡dispensed¡¡with£»¡¡and¡¡the¡¡propeller¡¡itself
is¡¡turned¡¡to¡¡give¡¡sufficient¡¡twist¡¡to¡¡the¡¡rubber¡¡for
this¡¡purpose¡£
THE¡¡POWER¡¡FOR¡¡MODEL¡¡AEROPLANES¡£One¡¡end
of¡¡the¡¡rubber¡¡is¡¡attached¡¡to¡¡the¡¡hook¡¡of¡¡the¡¡shaft
C£»¡¡and¡¡the¡¡other¡¡end¡¡to¡¡the¡¡hook¡¡or¡¡to¡¡the¡¡turnbuckle
G£»¡¡if¡¡it¡¡should¡¡be¡¡so¡¡equipped¡£
The¡¡rubbers¡¡are¡¡twisted¡¡in¡¡opposite¡¡directions£»
to¡¡correspond¡¡with¡¡the¡¡twist¡¡of¡¡the¡¡propeller
blades£»¡¡and¡¡when¡¡the¡¡propellers¡¡are¡¡permitted¡¡to
turn£»¡¡their¡¡grip¡¡on¡¡the¡¡air¡¡will¡¡cause¡¡the¡¡model¡¡to
shoot¡¡forwardly£»¡¡until¡¡the¡¡rubbers¡¡are¡¡untwisted£»
when¡¡the¡¡machine¡¡will¡¡gradually¡¡glide¡¡to¡¡the
ground¡£
MAKING¡¡THE¡¡PROPELLER¡£These¡¡should¡¡have
the¡¡pitch¡¡uniform¡¡on¡¡both¡¡ends£»¡¡and¡¡a¡¡simple
little¡¡device¡¡can¡¡be¡¡made¡¡to¡¡hold¡¡the¡¡twisted¡¡blade
after¡¡it¡¡has¡¡been¡¡steamed¡¡and¡¡bent¡£¡¡Birch¡¡and
holly¡¡are¡¡good¡¡woods¡¡for¡¡the¡¡blades¡£¡¡The¡¡strips
should¡¡be¡¡made¡¡thin¡¡and¡¡then¡¡boiled£»¡¡or£»¡¡what¡¡is
better¡¡still£»¡¡should¡¡be¡¡placed¡¡in¡¡a¡¡deep¡¡pan£»¡¡and
held¡¡on¡¡a¡¡grid¡¡above¡¡the¡¡water£»¡¡so¡¡they¡¡will¡¡be
thoroughly¡¡steamed¡£
They¡¡are¡¡then¡¡taken¡¡out¡¡and¡¡bent¡¡by¡¡hand£»¡¡or
secured¡¡between¡¡a¡¡form¡¡specially¡¡prepared¡¡for
the¡¡purpose¡£¡¡The¡¡device¡¡shown¡¡in¡¡Fig¡£¡¡88¡¡shows
a¡¡base¡¡board¡¡which¡¡has¡¡in¡¡the¡¡center¡¡a¡¡pair¡¡of
parallel¡¡pins¡¡A£»¡¡A£»¡¡slightly¡¡separated¡¡from¡¡each
other¡£
_Fig¡£¡¡88¡£¡¡Making¡¡the¡¡Propeller¡£_
At¡¡each¡¡end¡¡of¡¡the¡¡base¡¡board¡¡is¡¡a¡¡pair¡¡of¡¡holes
C£»¡¡D£»¡¡drilled¡¡in¡¡at¡¡an¡¡angle£»¡¡the¡¡angles¡¡being¡¡the
pitch¡¡desired¡¡for¡¡the¡¡ends¡¡of¡¡the¡¡propeller¡£¡¡In
one¡¡of¡¡these¡¡holes¡¡a¡¡pin¡¡E¡¡is¡¡placed£»¡¡so¡¡the¡¡pins
at¡¡the¡¡opposite¡¡ends¡¡project¡¡in¡¡different¡¡directions£»
and¡¡the¡¡tips¡¡of¡¡the¡¡propeller¡¡are¡¡held
against¡¡the¡¡ends¡¡of¡¡these¡¡pins£»¡¡while¡¡the¡¡middle
of¡¡the¡¡propeller¡¡is¡¡held¡¡between¡¡the¡¡parallel¡¡pins
A£»¡¡A¡£
The¡¡two¡¡holes£»¡¡at¡¡the¡¡two¡¡angles¡¡at¡¡the¡¡ends¡¡of
the¡¡board£»¡¡are¡¡for¡¡the¡¡purpose¡¡of¡¡making¡¡right
and¡¡left¡¡hand¡¡propellers£»¡¡as¡¡it¡¡is¡¡desirable¡¡to¡¡use
two¡¡propellers¡¡with¡¡the¡¡A¡shaped¡¡model¡£¡¡Two
propellers¡¡with¡¡the¡¡deltoid¡¡model¡¡are¡¡not¡¡so¡¡necessary¡£
After¡¡the¡¡twist¡¡is¡¡made¡¡and¡¡the¡¡blade¡¡properly
secured¡¡in¡¡position¡¡it¡¡should¡¡be¡¡allowed¡¡to¡¡thoroughly
dry£»¡¡and¡¡afterwards£»¡¡if¡¡it¡¡is¡¡coated¡¡with
shellac£»¡¡will¡¡not¡¡untwist£»¡¡as¡¡it¡¡is¡¡the¡¡changing
character¡¡of¡¡the¡¡atmosphere¡¡which¡¡usually¡¡causes
the¡¡twisted¡¡strips¡¡to¡¡change¡¡their¡¡positions¡£
Shellac¡¡prevents¡¡the¡¡moist¡¡atmosphere¡¡from¡¡affecting
them¡£
MATERIAL¡¡FOR¡¡PROPELLERS¡£Very¡¡light¡¡propellers
can¡¡also¡¡be¡¡made¡¡of¡¡thin£»¡¡annealed¡¡aluminum
sheets£»¡¡and¡¡the¡¡pins¡¡in¡¡that¡¡case¡¡will¡¡serve¡¡as
guides¡¡to¡¡enable¡¡you¡¡to¡¡get¡¡the¡¡desired¡¡pitch¡£
Fiber¡¡board¡¡may¡¡also¡¡be¡¡used£»¡¡but¡¡this¡¡is¡¡more
difficult¡¡to¡¡handle¡£
Another¡¡good¡¡material¡¡is¡¡celluloid¡¡sheets£»
which£»¡¡when¡¡cut¡¡into¡¡proper¡¡strips£»¡¡is¡¡dipped¡¡in
hot¡¡water£»¡¡for¡¡bending¡¡purposes£»¡¡and¡¡it¡¡readily
retains¡¡its¡¡shape¡¡when¡¡cooled¡£
RUBBERSuitable¡¡rubber¡¡for¡¡the¡¡strips¡¡are
readily¡¡obtainable¡¡in¡¡the¡¡market¡£¡¡Experiment
will¡¡soon¡¡show¡¡what¡¡size¡¡and¡¡lengths¡¡are¡¡best
adapted¡¡for¡¡the¡¡particular¡¡type¡¡of¡¡propellers
which¡¡you¡¡succeed¡¡in¡¡making¡£
PROPELLER¡¡SHAPE¡¡AND¡¡SIZE¡£A¡¡good¡¡proportion
of¡¡propeller¡¡is¡¡shown¡¡in¡¡Fig¡£¡¡89¡£¡¡This¡¡also
shows¡¡the¡¡form¡¡and¡¡manner¡¡of¡¡connecting¡¡the
shaft¡£¡¡The¡¡latter¡¡A¡¡has¡¡a¡¡hook¡¡B¡¡on¡¡one¡¡end¡¡to
which¡¡the¡¡rubber¡¡may¡¡be¡¡attached£»¡¡and¡¡its¡¡other
end¡¡is¡¡flattened£»¡¡as¡¡at¡¡C£»¡¡and¡¡secured¡¡to¡¡the¡¡blade
by¡¡two¡pointed¡¡brads¡¡D£»¡¡clinched¡¡on¡¡the¡¡other
side¡£
_Fig¡£¡¡89¡£¡¡Shape¡¡and¡¡Size¡£_
The¡¡collar¡¡E¡¡is¡¡soldered¡¡on¡¡the¡¡shaft£»¡¡and¡¡in
practice¡¡the¡¡shaft¡¡is¡¡placed¡¡through¡¡the¡¡bearing
hole¡¡at¡¡the¡¡end¡¡of¡¡the¡¡frame¡¡before¡¡the¡¡hook¡¡is
bent¡£
SUPPORTING¡¡SURFACES¡£The¡¡supporting¡¡surfaces
may¡¡be¡¡made¡¡perfectly¡¡flat£»¡¡although¡¡in¡¡this
particular¡¡it¡¡would¡¡be¡¡well¡¡to¡¡observe¡¡the¡¡rules
with¡¡respect¡¡to¡¡the¡¡camber¡¡of¡¡large¡¡machines¡£
CHAPTER¡¡XV
THE¡¡AEROPLANE¡¡IN¡¡THE¡¡GREAT¡¡WAR
DURING¡¡the¡¡civil¡¡war¡¡the¡¡Federal¡¡forces¡¡used
captive¡¡balloons¡¡for¡¡the¡¡purpose¡¡of¡¡discovering
the¡¡positions¡¡of¡¡the¡¡enemy¡£¡¡They¡¡were¡¡of¡¡great
service¡¡at¡¡that¡¡time£»¡¡although¡¡they¡¡were¡¡stationed
far¡¡within¡¡the¡¡lines¡¡to¡¡prevent¡¡hostile¡¡guns¡¡from
reaching¡¡them¡£
BALLOON¡¡OBSERVATIONS¡£Necessarily£»¡¡observations
from¡¡balloons¡¡were¡¡and¡¡are¡¡imperfect¡£¡¡It
was¡¡found¡¡to¡¡be¡¡very¡¡unsatisfactory¡¡during¡¡the
Russian¡Japanese¡¡war£»¡¡because¡¡the¡¡angle¡¡of¡¡vision
is¡¡very¡¡low£»¡¡and£»¡¡furthermore£»¡¡at¡¡such¡¡distances¡¡the
movements£»¡¡or¡¡even¡¡the¡¡location¡¡of¡¡troops¡¡is¡¡not
observable£»¡¡except¡¡under¡¡the¡¡most¡¡favorable¡¡conditions¡£
Balloon¡¡observation¡¡during¡¡the¡¡progress¡¡of¡¡a
battle¡¡is¡¡absolutely¡¡useless£»¡¡because¡¡the¡¡smoke
from¡¡the¡¡firing¡¡line¡¡is£»¡¡necessarily£»¡¡between¡¡the
balloon¡¡and¡¡the¡¡enemy£»¡¡so¡¡that¡¡the¡¡aerial¡¡scout
has¡¡no¡¡opportunity¡¡to¡¡make¡¡any¡¡observations£»¡¡even
in¡¡detached¡¡portions¡¡of¡¡the¡¡fighting¡¡zone£»¡¡which
are¡¡of¡¡any¡¡value¡¡to¡¡the¡¡commanders¡£
CHANGED¡¡CONDITIONS¡¡OF¡¡WARFARE¡£Since¡¡our
great¡¡war£»¡¡conditions¡¡pertaining¡¡to¡¡guns¡¡have¡¡been
revolutionized¡£¡¡Now¡¡the¡¡ranges¡¡are¡¡so¡¡great¡¡that
captive¡¡balloons¡¡would¡¡have¡¡to¡¡be¡¡located¡¡far¡¡in
the¡¡rear£»¡¡and¡¡at¡¡such¡¡a¡¡great¡¡distance¡¡from¡¡the
firing¡¡line¡¡that¡¡even¡¡the¡¡best¡¡field¡¡glasses¡¡would
be¡¡useless¡£
The¡¡science¡¡of¡¡war¡¡has¡¡also¡¡evolved¡¡another
condition¡£¡¡Soldiers¡¡are¡¡no¡¡longer¡¡exposed¡¡during
artillery¡¡attacks¡£¡¡Uniforms¡¡are¡¡made¡¡to¡¡imitate
natural¡¡objects¡£¡¡The¡¡khaki¡¡suits¡¡were¡¡designed
to¡¡imitate¡¡the¡¡yellow¡¡veldts¡¡of¡¡South¡¡Africa£»
the¡¡gray¡green¡¡garments¡¡of¡¡the¡¡German
forces¡¡are¡¡designed¡¡to¡¡simulate¡¡the¡¡green¡¡fields
of¡¡the¡¡north¡£
THE¡¡EFFORT¡¡TO¡¡CONCEAL¡¡COMBATANTS¡£The
French¡¡have¡¡discarded¡¡the¡¡historic¡¡red¡¡trousers£»
and¡¡the¡¡elimination¡¡of¡¡lace£»¡¡white¡¡gloves£»¡¡and
other¡¡telltale¡¡insignias¡¡of¡¡the¡¡officers£»¡¡have¡¡been
dispensed¡¡with¡¡by¡¡special¡¡orders¡£
In¡¡the¡¡great¡¡European¡¡war¡¡armies¡¡have¡¡burrowed
in¡¡the¡¡earth¡¡along¡¡battle¡¡lines¡¡hundreds¡¡of
miles¡¡in¡¡length£»¡¡made¡¡covered¡¡trenches£»¡¡prepared
artificial¡¡groves¡¡to¡¡conceal¡¡batteries£»¡¡and¡¡in¡¡many
ingenious¡¡ways¡¡endeavored¡¡to¡¡make¡¡the¡¡battlefield
an¡¡imitation¡¡field¡¡of¡¡nature¡£
SMOKELESS¡¡POWDER¡£While¡¡smokeless¡¡powder
has¡¡been¡¡utilized¡¡to¡¡still¡¡further¡¡hide¡¡a¡¡fighting
force£»¡¡it¡¡has£»¡¡in¡¡a¡¡measure£»¡¡uncovered¡¡itself£»¡¡as
the¡¡battlefield¡¡is¡¡not¡¡now£»¡¡as¡¡in¡¡olden¡¡times£»¡¡overspread
with¡¡masses¡¡of¡¡rolling¡¡smoke¡£
Nevertheless£»¡¡over¡¡every¡¡battlefield¡¡there¡¡is¡¡a
haze¡¡which¡¡can¡¡be¡¡penetrated¡¡only¡¡from¡¡above£»
hence¡¡the¡¡possibilities¡¡of¡¡utilizing¡¡the¡¡aeroplane
in¡¡war¡¡became¡¡the¡¡most¡¡important¡¡study¡¡with¡¡all
nations£»¡¡as¡¡soon¡¡as¡¡flying¡¡became¡¡an¡¡accomplished
fact¡£
INVENTIONS¡¡TO¡¡ATTACK¡¡AERIAL¡¡CRAFT¡£Before
any¡¡nation¡¡had¡¡the¡¡opportunity¡¡to¡¡make¡¡an¡¡actual
test¡¡on¡¡the¡¡battlefield£»¡¡inventors¡¡were¡¡at¡¡work¡¡to
devise¡¡a¡¡means¡¡whereby¡¡an¡¡aerial¡¡foe¡¡could¡¡be
met¡£¡¡In¡¡a¡¡measure¡¡the¡¡aerial¡¡gun¡¡has¡¡been¡¡successful£»
but¡¡months¡¡of¡¡war¡¡has¡¡shown¡¡that¡¡the
aeroplane¡¡is¡¡one¡¡of¡¡the¡¡strongest¡¡arms¡¡of¡¡the
service¡¡in¡¡actual¡¡warfare¡£
It¡¡was¡¡assumed¡¡prior¡¡to¡¡the¡¡European¡¡war¡¡that
the¡¡chief¡¡function¡¡of¡¡the¡¡aeroplane¡¡would¡¡be¡¡the
dropping¡¡of¡¡bombs£»that¡¡is¡¡for¡¡service¡¡in¡¡attacking
a¡¡foe¡£¡¡Actual¡¡practice¡¡has¡¡not¡¡justified
this¡¡theory¡£¡¡In¡¡some¡¡places¡¡the¡¡appearance¡¡of
the¡¡aeroplane¡¡has¡¡caused¡¡terror£»¡¡but¡¡it¡¡has¡¡been
found¡¡the¡¡great¡¡value¡¡is¡¡its¡¡scouting¡¡advantages¡£
FUNCTION¡¡OF¡¡THE¡¡AEROPLANE¡¡IN¡¡WAR¡£While
bomb¡¡throwing¡¡may¡¡in¡¡the¡¡future¡¡be¡¡perfected£»
it¡¡is¡¡not¡¡at¡¡all¡¡an¡¡easy¡¡problem¡¡for¡¡an¡¡aviator¡¡to
do¡¡