THE　RANGE　OF　ITS　USE。The　subject　might　be
  illustrated　by　assuming　that　we　have　a　line　running
  from　A　to　Z；　which　indicates　the　range　of
  speeds　in　aeroplanes。　The　limits　of　speeds　are
  fairly　stated　as　being　within　thirty　and　eighty…
  five　miles　per　hour。　Less　than　thirty　miles　are
  impossible　with　any　type　of　plane；　and　while　some
  have　made　higher　speeds　than　eighty…five　miles　it
  may　be　safe　to　assume　that　such　flights　took　place
  under　conditions　where　the　wind　contributed　to
  the　movement。
  _Fig。　32。　Chart　showing　Range　of　Uses_
  COMMERCIAL　UTILITY。Before　machines　can　be
  used　successfully　they　must　be　able　to　attain
  slower　speeds。　Alighting　is　the　danger　factor。
  Speed　machines　are　dangerous；　not　in　flight　or
  at　high　speeds；　but　when　attempting　to　land。　A
  large　plane　surface　is　incompatible　with　speed；
  which　is　another　illustration　that　at　high　velocities
  supporting　surfaces　are　not　necessary。
  Commercial　uses　require　safety　as　the　first　element；
  and　reliability　as　the　next　essential。　For
  passenger　service　there　must　be　an　assurance　that
  it　will　not　overturn；　or　that　in　landing　danger　is
  not　ever…present。　For　the　carrying　of　freight　interrupted
  service　will　militate　against　it。
  How　few　are　the　attempts　to　solve　the　problem
  of　decreased　speed；　and　what　an　eager；　restless
  campaign　is　being　waged　to　go　faster　and　faster；
  and　the　addition　of　every　mile　above　the　record
  is　hailed　as　another　illustration　of　the　perfection
  （？）　of　the　flying　machine。
  To　be　able　to　navigate　a　machine　at　ten；　or　fifteen
  miles　an　hour；　would　scarcely　be　interesting
  enough　to　merit　a　paragraph；　but　such　an　accomplishment
  would　be　of　far　more　value　than　all　of
  Pequod's　feats；　and　be　more　far…reaching　in　its
  effects　than　a　flight　of　two　hundred　miles　per　hour。
  CHAPTER　VIII
  KITES　AND　GLIDERS
  KITES　are　of　very　ancient　origin；　and　in　China；
  Japan；　and　the　Malayan　Peninsula；　they　have　been
  used　for　many　years　as　toys；　and　for　the　purposes
  of　exhibiting　forms　of　men；　animals；　and　particularly
  dragons；　in　their　periodical　displays。
  THE　DRAGON　KITE。The　most　noted　of　all　are
  the　dragon　kites；　many　of　them　over　a　hundred
  feet　in　length；　are　adapted　to　sail　along　majestically；
  their　sinuous　or　snake…like　motions　lending
  an　idea　of　reality　to　their　gorgeously…colored　appearance
  in　flight。
  ITS　CONSTRUCTION。It　is　very　curiously
  wrought；　and　as　it　must　be　extremely　light；　bamboo
  and　rattan　are　almost　wholly　used；　together
  with　rice　paper；　in　its　construction。
  Fig。　33　shows　one　form　of　the　arrangement；　in
  which　the　bamboo　rib；　A；　in　which　only　two　sections
  are　shown；　as　B；　B；　form　the　backbone；　and
  these　sections　are　secured　together　with　pivot
  pins　C。　Each　section　has　attached　thereto　a
  hoop；　or　circularly…formed　rib；　D；　the　rib　passing
  through　the　section　B；　and　these　ribs　are
  connected　together　loosely　by　cords　E；　which　run
  from　one　to　the　other；　as　shown。
  These　circular　ribs；　D；　are　designed　to　carry　a
  plurality　of　light　paper　disks；　F；　which　are　attached
  at　intervals；　and　they　are　placed　at　such
  angles　that　they　serve　as　small　wing　surfaces　or
  aeroplanes　to　hold　the　structure　in　flight。
  _Fig。　33。　Ribs　of　Dragon　Kite_
  THE　MALAY　KITE。The　Malay　kite；　of　which
  Fig。　34　shows　the　structure；　is　merely　made　up　of
  two　cross　sticks；　A；　B；　the　vertical　strip；　A；　being
  bent　and　rigid；　whereas　the　cross　stick；　B；　is　light
  and　yielding；　so　that　when　in　flight　it　will　bend；
  as　shown；　and　as　a　result　it　has　wonderful　stability
  due　to　the　dihedral　angles　of　the　two　surfaces。　This　kite
  requires　no　tail　to　give　it　stability。
  _Fig。　34。　The　Malay　Kite。_
  DIHEDRAL　ANGLES。This　is　a　term　to　designate
  a　form　of　disposing　of　the　wings　which　has　been
  found　of　great　service　in　the　single　plane　machines。
  A　plane　which　is　disposed　at　a　rising
  angle；　as　A；　A；　Fig。　35；　above　the　horizontal　line；
  is　called　dihedral；　or　diedral。
  _Fig。　35。　Dihedral　Angle。_
  This　arrangement　in　monoplanes　does　away
  with　the　necessity　of　warping　the　planes；　or
  changing　them　while　in　flight。　If；　however；　the　angle
  is　too　great；　the　wind　from　either　quarter　is　liable
  to　raise　the　side　that　is　exposed。
  THE　COMMON　KITE。While　the　Malay　kite　has
  only　two　points　of　cord　attachment；　both　along
  the　vertical　rib；　the　common　kite；　as　shown　in
  Fig。　36；　has　a　four…point　connection；　to　which　the
  flying　cord　is　attached。　Since　this　form　has　no
  dihedral　angle；　it　is　necessary　to　supply　a　tail；
  which　thus　serves　to　keep　it　in　equilibrium；　while
  in　flight。
  _Fig。　36。　Common　Kite。_
  Various　modifications　have　grown　out　of　the
  Malay　kite。　One　of　these　forms；　designed　by
  Eddy；　is　exactly　like　the　Malay　structure；　but　instead
  of　having　a　light　flexible　cross　piece；　it　is
  bent　to　resemble　a　bow；　so　that　it　is　rigidly　held
  in　a　bent　position；　instead　of　permitting　the　wind
  to　give　it　the　dihedral　angle。
  THE　BOW　KITE。Among　the　different　types　are
  the　bow　kite；　Fig。　37；　and　the　sexagonal　structure；
  Fig。　38；　the　latter　form　affording　an　especially
  large　surface。
  _Fig。　37。　Bow　Kite。…
  _Fig。　38。　Hexagonal　Kite。_
  THE　BOX　KITE。The　most　marked　improvement
  in　the　form　of　kites　was　made　by　Hargreaves；
  in　1885；　and　called　the　box　kite。　It　has　wonderful
  stability；　and　its　use；　with　certain　modifications；
  in　Weather　Bureau　experiments；　have　proven　its
  value。
  It　is　made　in　the　form　of　two　boxes；　A；　B；　open
  at　the　ends；　which　are　secured　together　by　means
  of　longitudinal　bars；　C；　that　extends　from　one　to
  the　other；　so　that　they　are　held　apart　a　distance；
  approximately；　equal　to　the　length　of　one　of　the
  boxes。
  _Fig。　39。　Hargreave　Kite。_
  Their　fore　and　aft　stability　is　so　perfect　that
  the　flying　cord　D　is　attached　at　one　point　only；
  and　the　sides　of　the　boxes　provide　lateral　stability
  to　a　marked　degree。
  THE　VOISON　BIPLANE。This　kind　of　kite　furnished
  the　suggestion　for　the　Voison　biplane；
  which　was　one　of　the　earlier　productions　in　flying
  machines。
  Fig。　40　shows　a　perspective　of　the　Voison　plane；
  which　has　vertical　planes　A；　A；　at　the　ends；　and
  also　intermediate　curtains　B；　B。　This　was　found
  to　be　remarkably　stable；　but　during　its　turning
  movements；　or　in　high　winds；　was　not　satisfactory；
  and　for　that　reason　was　finally　abandoned。
  LATERAL　STABILITY　IN　KITES　NOT　CONCLUSIVE　AS
  TO　PLANES。This　is　instanced　to　show　that　while
  such　a　form　is　admirably　adapted　for　kite　purposes；
  where　vertical　curtains　are　always　in　line
  with　the　wind　movement；　and　the　structure　is　held
  taut　by　a　cord；　the　lateral　effect；　when　used　on　a
  machine　which　does　not　at　all　times　move　in　line
  with　the　moving　air　current。　A　condition　is　thus
  set　up　which　destroys　the　usefulness　of　the　box
  kite　formation。
  _Fig。　40。　Voison　Biplane。_
  THE　SPEAR　KITE。This　is　a　novel　kite；　with
  remarkable　steadiness　and　is　usually　made　with
  the　wings　on　the　rear　end　larger　than　those　on
  the　forward　end　（Fig。　41）；　as　thereby　the　cord
  A　can　be　attached　to　the　spear　midway　between
  the　two　sets　of　wings。
  _Fig。　41。　Spear　Kite。_
  THE　CELLULAR　KITE。Following　out　the　suggestion
  of　the　Hargreaves　kite；　numerous　forms
  embodying　the　principle　of　the　box　structure　were
  made　and　put　on　the　market　before　the　aeroplane
  became　a　reality。
  _Fig。　42。　Cellular　Kite。_
  A　structure　of　this　form　is　illustrated　in　Fig。
  42。　Each　box；　as　A；　B；　has　therein　a　plurality　of
  vertical　and　horizontal　partitions；　so　that　a　number
  of　cells　are　provided；　the　two　cell…like　boxes
  being　held　apart　by　a　bar　C；　axially　arranged。
  This　type　is　remarkably　stable；　due　to　the　small
  cells；　and　kites　of　this　kind　are　largely　used　for
  making　scientific　experiments。
  THE　TETRAHEDRAL　KITE。Prof。　Bell；　inventor
  of　the　telephone；　gave　a　great　deal　of　study　to
  kites；　which　resulted　in　the　tetrahedral　formation；
  as　shown　in　Fig。　43。
  _Fig。　43。　Tetrahedral　Kite。_
  The　structure；　apparently；　is　somewhat　complicated；
  but　an　examination　of　a　single　pair　of
  blades；　as　shown　at　A；　shows　that　it　is　built　up　of
  triangularly…formed　pieces；　and　that　the　openings
  between　the　pieces　are　equal　to　the　latter；　thereby
  providing　a　form　of　kite　which　possesses　equilibrium
  to　a　great　degree。
  It　has　never　been　tried　with　power；　and　it　is
  doubtful　whether　it　would　be　successful　as　a　sustaining
  surface　for　flying　machines；　for　the　same
  reasons　that　caused　failure　with　the　box…like　formation
  of　the　Voison　Machine。
  THE　DELTOID。The　deltoid　is　the　simplest；　and
  the　most　easily　constructed　of　all　the　kites。　It　is
  usually　made　from　stiff　cardboard；　A…shaped　in
  outline；　as　shown　in　Figs。　44　and　45；　and　bent　along
  a　central　line；　as　at　A；　forming　two　wings；　each
  of　which　is　a　right…angled　triangle。
  _Fig。　44。　and　45。　Deltoid　Formation。_
  The　peculiarity　of　t