man　uses　the　types　which　nature　provides　in　devising
  the　many　inventions　which　ingenuity　has
  brought　forth。
  PRINCIPLES　ESSENTIAL；　NOT　FORMS。It　is　essential
  that　man　shall　follow　nature's　laws。　He　cannot
  evade　the　principles　on　which　the　operations
  of　mechanism　depend；　but　in　doing　so　he　has；　in
  nearly　every　instance；　departed　from　the　form
  which　nature　has　suggested；　and　made　the　machine
  irrespective　of　nature's　type。
  Let　us　consider　some　of　these　striking　differences
  to　illustrate　this　fact。　Originally　pins　were
  stuck　upon　a　paper　web　by　hand；　and　placed　in
  rows；　equidistant　from　each　other。　This　necessitates
  the　cooperative　function　of　the　fingers　and
  the　eye。　An　expert　pin　sticker　could　thus　assemble
  from　four　to　five　thousand　pins　a　day。
  The　first　mechanical　pinsticker　placed　over
  500；000　pins　a　day　on　the　web；　rejecting　every　bent
  or　headless　pin；　and　did　the　work　with　greater
  accuracy　than　it　was　possible　to　do　it　by　hand。
  There　was　not　the　suggestion　of　an　eye；　or　a　finger
  in　the　entire　machine；　to　show　that　nature　furnished
  the　type。
  NATURE　NOT　THE　GUIDE　AS　TO　FORMS。Nature
  does　not　furnish　a　wheel　in　any　of　its　mechanical
  expressions。　If　man　followed　nature's　form
  in　the　building　of　the　locomotive；　it　would　move
  along　on　four　legs　like　an　elephant。　Curiously
  enough；　one　of　the　first　road　wagons　had　〃push
  legs；〃an　instance　where　the　mechanic　tried　to
  copy　nature；and　failed。
  THE　PROPELLER　TYPE。The　well　known　propeller
  is　a　type　of　wheel　which　has　no　prototype　in
  nature。　It　is　maintained　that　the　tail　of　a　fish
  in　its　movement　suggested　the　propeller；　but　the
  latter　is　a　long　departure　from　it。
  The　Venetian　rower；　who　stands　at　the　stern；
  and　with　a　long…bladed　oar；　fulcrumed　to　the
  boat's　extremity；　in　making　his　graceful　lateral
  oscillations；　simulates　the　propelling　motion　of
  the　tail　in　an　absolutely　perfect　manner；　but　it　is
  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。　T