flying machines-µÚ24ÕÂ
°´¼üÅÌÉÏ·½Ïò¼ü ¡û »ò ¡ú ¿É¿ìËÙÉÏÏ·ҳ£¬°´¼üÅÌÉ쵀 Enter ¼ü¿É»Øµ½±¾ÊéĿ¼ҳ£¬°´¼üÅÌÉÏ·½Ïò¼ü ¡ü ¿É»Øµ½±¾Ò³¶¥²¿£¡
¡ª¡ª¡ª¡ªÎ´ÔĶÁÍꣿ¼ÓÈëÊéÇ©ÒѱãÏ´μÌÐøÔĶÁ£¡
which¡¡is¡¡produced¡¡when¡¡a¡¡supplementary¡¡plane¡¡on¡¡one
side¡¡is¡¡tilted¡¡or¡¡raised¡¡and¡¡the¡¡other¡¡stimultaneously
tilted¡¡or¡¡lowered¡£¡¡I¡¡am¡¡also¡¡satisfied¡¡that¡¡the¡¡rear
rudder¡¡is¡¡turned¡¡by¡¡the¡¡operator¡¡to¡¡the¡¡side¡¡having¡¡the
least¡¡angle¡¡of¡¡incidence¡¡and¡¡that¡¡such¡¡turning¡¡is¡¡done
at¡¡the¡¡time¡¡the¡¡supplementary¡¡planes¡¡are¡¡raised
or¡¡depressed¡¡to¡¡prevent¡¡tilting¡¡or¡¡upsetting¡¡the¡¡machine¡£
On¡¡the¡¡papers¡¡presented¡¡I¡¡incline¡¡to¡¡the¡¡view£»¡¡as¡¡already
indicated£»¡¡that¡¡the¡¡claims¡¡of¡¡the¡¡patent¡¡in¡¡suit¡¡should¡¡be
broadly¡¡construed£»¡¡and¡¡when¡¡given¡¡such¡¡construction£»
the¡¡elements¡¡of¡¡the¡¡Wright¡¡machine¡¡are¡¡found¡¡in¡¡defendants'
machine¡¡performing¡¡the¡¡same¡¡functional¡¡result¡£
There¡¡are¡¡dissimilarities¡¡in¡¡the¡¡defendants'¡¡structure
changes¡¡of¡¡form¡¡and¡¡strengthening¡¡of¡¡partswhich¡¡may
be¡¡improvements£»¡¡but¡¡such¡¡dissimilarities¡¡seem¡¡to¡¡me¡¡to
have¡¡no¡¡bearing¡¡upon¡¡the¡¡means¡¡adopted¡¡to¡¡preserve¡¡the
equilibrium£»¡¡which¡¡means¡¡are¡¡the¡¡equivalent¡¡of¡¡the¡¡claims
in¡¡suit¡¡and¡¡attain¡¡an¡¡identical¡¡result¡£
Variance¡¡From¡¡Patent¡¡Immaterial¡£
¡¨Defendants¡¡further¡¡contend¡¡that¡¡the¡¡curved¡¡or¡¡arched
surfaces¡¡of¡¡the¡¡Wright¡¡aeroplanes¡¡in¡¡commercial¡¡use¡¡are
departures¡¡from¡¡the¡¡patent£»¡¡which¡¡describes¡¡'substantially
flat¡¡surfaces£»'¡¡and¡¡that¡¡such¡¡a¡¡construction¡¡would
be¡¡wholly¡¡impracticable¡£¡¡The¡¡drawing£»¡¡Fig¡£¡¡3£»¡¡however£»
attached¡¡to¡¡the¡¡specification£»¡¡shows¡¡a¡¡curved¡¡line¡¡inward
of¡¡the¡¡aeroplane¡¡with¡¡straight¡¡lateral¡¡edges£»¡¡and¡¡considering
such¡¡drawing¡¡with¡¡the¡¡terminology¡¡of¡¡the¡¡specification£»
the¡¡slight¡¡arching¡¡of¡¡the¡¡surface¡¡is¡¡not¡¡thought
a¡¡material¡¡departure£»¡¡at¡¡any¡¡rate£»¡¡the¡¡patent¡¡in¡¡issue
does¡¡not¡¡belong¡¡to¡¡the¡¡class¡¡of¡¡patents¡¡which¡¡requires
narrowing¡¡to¡¡the¡¡details¡¡of¡¡construction¡£¡¨
¡¨June¡¡Bug¡¨¡¡First¡¡Infringement¡£
Referring¡¡to¡¡the¡¡matter¡¡of¡¡priority£»¡¡the¡¡judge¡¡said£º
¡¨Indeed£»¡¡no¡¡one¡¡interfered¡¡with¡¡the¡¡rights¡¡of¡¡the
patentees¡¡by¡¡constructing¡¡machines¡¡similar¡¡to¡¡theirs¡¡until
in¡¡July£»¡¡1908£»¡¡when¡¡Curtiss¡¡exhibited¡¡a¡¡flying¡¡machine
which¡¡he¡¡called¡¡the¡¡'June¡¡Bug¡£'¡¡He¡¡was¡¡immediately
notified¡¡by¡¡the¡¡patentees¡¡that¡¡such¡¡machine¡¡with¡¡its
movable¡¡surfaces¡¡at¡¡the¡¡tips¡¡of¡¡wings¡¡infringed¡¡the¡¡patent
in¡¡suit£»¡¡and¡¡he¡¡replied¡¡that¡¡he¡¡did¡¡not¡¡intend¡¡to¡¡publicly
exhibit¡¡the¡¡machine¡¡for¡¡profit£»¡¡but¡¡merely¡¡was¡¡engaged
in¡¡exhibiting¡¡it¡¡for¡¡scientific¡¡purposes¡¡as¡¡a¡¡member
of¡¡the¡¡Aerial¡¡Experiment¡¡Association¡£¡¡To¡¡this¡¡the¡¡patentees
did¡¡not¡¡object¡£¡¡Subsequently£»¡¡however£»¡¡the¡¡machine£»
with¡¡supplementary¡¡planes¡¡placed¡¡midway¡¡between
the¡¡upper¡¡and¡¡lower¡¡aeroplanes£»¡¡was¡¡publicly¡¡exhibited
by¡¡the¡¡defendant¡¡corporation¡¡and¡¡used¡¡by¡¡Curtiss¡¡in
aerial¡¡flights¡¡for¡¡prizes¡¡and¡¡emoluments¡£¡¡It¡¡further¡¡appears
that¡¡the¡¡defendants¡¡now¡¡threaten¡¡to¡¡continue¡¡such
use¡¡for¡¡gain¡¡and¡¡profit£»¡¡and¡¡to¡¡engage¡¡in¡¡the¡¡manufacture
and¡¡sale¡¡of¡¡such¡¡infringing¡¡machines£»¡¡thereby¡¡becoming
an¡¡active¡¡rival¡¡of¡¡complainant¡¡in¡¡the¡¡business¡¡of
constructing¡¡flying¡¡machines¡¡embodying¡¡the¡¡claims¡¡in¡¡suit£»
but¡¡such¡¡use¡¡of¡¡the¡¡infringing¡¡machines¡¡it¡¡is¡¡the¡¡duty
of¡¡this¡¡court£»¡¡on¡¡the¡¡papers¡¡presented£»¡¡to¡¡enjoin¡£
¡¨The¡¡requirements¡¡in¡¡patent¡¡causes¡¡for¡¡the¡¡issuance
of¡¡an¡¡injunction¡¡pendente¡¡litethe¡¡validity¡¡of¡¡the¡¡patent£»
general¡¡acquiescence¡¡by¡¡the¡¡public¡¡and¡¡infringement
by¡¡the¡¡defendantsare¡¡so¡¡reasonably¡¡clear¡¡that¡¡I¡¡believe
if¡¡not¡¡probable¡¡the¡¡complainant¡¡may¡¡succeed¡¡at¡¡final
hearing£»¡¡and¡¡therefore£»¡¡status¡¡quo¡¡should¡¡be¡¡preserved
and¡¡a¡¡preliminary¡¡injunction¡¡granted¡£
¡¨So¡¡ordered¡£¡¨
Points¡¡Claimed¡¡By¡¡Curtiss¡£
That¡¡the¡¡Herring¡Curtiss¡¡Co¡£¡¡will¡¡appeal¡¡is¡¡a¡¡certainty¡£
Mr¡£¡¡Emerson¡¡R¡£¡¡Newell£»¡¡counsel¡¡for¡¡the¡¡company£»
states¡¡its¡¡case¡¡as¡¡follows£º
¡¨The¡¡Curtiss¡¡machine¡¡has¡¡two¡¡main¡¡supporting¡¡surfaces£»
both¡¡of¡¡which¡¡are¡¡curved¡¡*¡¡*¡¡*¡¡and¡¡are¡¡absolutely
rigid¡¡at¡¡all¡¡times¡¡and¡¡cannot¡¡be¡¡moved£»¡¡warped¡¡or
distorted¡¡in¡¡any¡¡manner¡£¡¡The¡¡front¡¡horizontal¡¡rudder¡¡is
used¡¡for¡¡the¡¡steering¡¡up¡¡or¡¡down£»¡¡and¡¡the¡¡rear¡¡vertical
rudder¡¡is¡¡used¡¡only¡¡for¡¡steering¡¡to¡¡the¡¡right¡¡or¡¡left£»¡¡in
the¡¡same¡¡manner¡¡as¡¡a¡¡boat¡¡is¡¡steered¡¡by¡¡its¡¡rudder¡£¡¡The
machine¡¡is¡¡provided¡¡at¡¡the¡¡rear¡¡with¡¡a¡¡fixed¡¡horizontal
surface£»¡¡which¡¡is¡¡not¡¡present¡¡in¡¡the¡¡machine¡¡of¡¡the¡¡patent£»
and¡¡which¡¡has¡¡a¡¡distinct¡¡advantage¡¡in¡¡the¡¡operation
of¡¡defendants'¡¡machine£»¡¡as¡¡will¡¡be¡¡hereafter¡¡discussed¡£
Does¡¡Not¡¡Warp¡¡Main¡¡Surface¡£
¡¨Defendants'¡¡machine¡¡does¡¡not¡¡use¡¡the¡¡warping¡¡of¡¡the
main¡¡supporting¡¡surfaces¡¡in¡¡restoring¡¡the¡¡lateral¡¡equilibrium£»
but¡¡has¡¡two¡¡comparatively¡¡small¡¡pivoted¡¡balancing
surfaces¡¡or¡¡rudders¡£¡¡When¡¡one¡¡end¡¡of¡¡the¡¡machine
is¡¡tipped¡¡up¡¡or¡¡down¡¡from¡¡the¡¡normal£»¡¡these¡¡planes¡¡may
be¡¡thrown¡¡in¡¡opposite¡¡directions¡¡by¡¡the¡¡operator£»¡¡and
so¡¡steer¡¡each¡¡end¡¡of¡¡the¡¡machine¡¡up¡¡or¡¡down¡¡to¡¡its
normal¡¡level£»¡¡at¡¡which¡¡time¡¡tension¡¡upon¡¡them¡¡is¡¡released
and¡¡they¡¡are¡¡moved¡¡back¡¡by¡¡the¡¡pressure¡¡of¡¡the
wind¡¡to¡¡their¡¡normal¡¡position¡£
Rudder¡¡Used¡¡Only¡¡For¡¡Steering¡£
¡¨When¡¡defendants'¡¡balancing¡¡surfaces¡¡are¡¡moved¡¡they
present¡¡equal¡¡angles¡¡of¡¡incidence¡¡to¡¡the¡¡normal¡¡rush
of¡¡air¡¡and¡¡equal¡¡resistances£»¡¡at¡¡each¡¡side¡¡of¡¡the¡¡machine£»
and¡¡there¡¡is¡¡therefore¡¡no¡¡tendency¡¡to¡¡turn¡¡around¡¡a
vertical¡¡axis¡¡as¡¡is¡¡the¡¡case¡¡of¡¡the¡¡machine¡¡of¡¡the¡¡patent£»
consequently¡¡no¡¡reason¡¡or¡¡necessity¡¡for¡¡turning¡¡the¡¡vertical
rear¡¡rudder¡¡in¡¡defendants'¡¡machine¡¡to¡¡counteract¡¡any
such¡¡turning¡¡tendency¡£¡¡At¡¡any¡¡rate£»¡¡whatever¡¡may¡¡be
the¡¡theories¡¡in¡¡regard¡¡to¡¡this¡¡matter£»¡¡the¡¡fact¡¡is¡¡that
the¡¡operator¡¡of¡¡defendants'¡¡machine¡¡does¡¡not¡¡at¡¡any
time¡¡turn¡¡his¡¡vertical¡¡rudder¡¡to¡¡counteract¡¡any¡¡turning
tendency¡¡clue¡¡to¡¡the¡¡side¡¡balancing¡¡surfaces£»¡¡but¡¡only
uses¡¡it¡¡to¡¡steer¡¡the¡¡machine¡¡the¡¡same¡¡as¡¡a¡¡boat¡¡is
steered¡£¡¨
Aero¡¡Club¡¡Recognizes¡¡Wrights¡£
The¡¡Aero¡¡Club¡¡of¡¡America¡¡has¡¡officially¡¡recognized
the¡¡Wright¡¡patents¡£¡¡This¡¡course¡¡was¡¡taken¡¡following¡¡a
conference¡¡held¡¡April¡¡9th£»¡¡1910£»¡¡participated¡¡in¡¡by¡¡William
Wright¡¡and¡¡Andrew¡¡Freedman£»¡¡representing¡¡the
Wright¡¡Co¡££»¡¡and¡¡the¡¡Aero¡¡Club's¡¡committee£»¡¡of¡¡Philip
T¡£¡¡Dodge£»¡¡W¡£¡¡W¡£¡¡Miller£»¡¡L¡£¡¡L¡£¡¡Gillespie£»¡¡Wm¡£¡¡H¡£¡¡Page
and¡¡Cortlandt¡¡F¡£¡¡Bishop¡£
At¡¡this¡¡meeting¡¡arrangements¡¡were¡¡made¡¡by¡¡which
the¡¡Aero¡¡Club¡¡recognizes¡¡the¡¡Wright¡¡patents¡¡and¡¡will
not¡¡give¡¡its¡¡section¡¡to¡¡any¡¡open¡¡meet¡¡where¡¡the¡¡promoters
thereof¡¡have¡¡not¡¡secured¡¡a¡¡license¡¡from¡¡the
Wright¡¡Company¡£
The¡¡substance¡¡of¡¡the¡¡agreement¡¡was¡¡that¡¡the¡¡Aero
Club¡¡of¡¡America¡¡recognizes¡¡the¡¡rights¡¡of¡¡the¡¡owners¡¡of
the¡¡Wright¡¡patents¡¡under¡¡the¡¡decisions¡¡of¡¡the¡¡Federal
courts¡¡and¡¡refuses¡¡to¡¡countenance¡¡the¡¡infringement¡¡of
those¡¡patents¡¡as¡¡long¡¡as¡¡these¡¡decisions¡¡remain¡¡in¡¡force¡£
In¡¡the¡¡meantime£»¡¡in¡¡order¡¡to¡¡encourage¡¡aviation£»¡¡both
at¡¡home¡¡and¡¡abroad£»¡¡and¡¡in¡¡order¡¡to¡¡permit¡¡foreign
aviators¡¡to¡¡take¡¡part¡¡in¡¡aviation¡¡contests¡¡in¡¡this¡¡country
it¡¡was¡¡agreed¡¡that¡¡the¡¡Aero¡¡Club¡¡of¡¡America£»¡¡as¡¡the
American¡¡representative¡¡of¡¡the¡¡International¡¡Aeronautic
Federation£»¡¡should¡¡approve¡¡only¡¡such¡¡public¡¡contests
as¡¡may¡¡be¡¡licensed¡¡by¡¡the¡¡Wright¡¡Company¡¡and¡¡that
the¡¡Wright¡¡Company£»¡¡on¡¡the¡¡other¡¡hand£»¡¡should¡¡encourage
the¡¡holding¡¡of¡¡open¡¡meets¡¡or¡¡contests¡¡where¡¡ever¡¡approved¡¡as
aforesaid¡¡by¡¡the¡¡Aero¡¡Club¡¡of¡¡America
by¡¡granting¡¡licenses¡¡to¡¡promoters¡¡who¡¡make¡¡satisfactory
arrangements¡¡with¡¡the¡¡company¡¡for¡¡its¡¡compensation
for¡¡the¡¡use¡¡of¡¡its¡¡patents¡£¡¡At¡¡such¡¡licensed¡¡meet¡¡any
machine¡¡of¡¡any¡¡make¡¡may¡¡participate¡¡freely¡¡without
securing¡¡any¡¡further¡¡license¡¡or¡¡permit¡£¡¡The¡¡details¡¡and
terms¡¡of¡¡all¡¡meets¡¡will¡¡be¡¡arranged¡¡by¡¡the¡¡committee
having¡¡in¡¡charge¡¡the¡¡interests¡¡of¡¡both¡¡organizations¡£
CHAPTER¡¡XXIV¡£
HINTS¡¡ON¡¡PROPELLER¡¡CONSTRUCTION¡£
Every¡¡professional¡¡aviator¡¡has¡¡his¡¡own¡¡ideas¡¡as¡¡to¡¡the
design¡¡of¡¡the¡¡propeller£»¡¡one¡¡of¡¡the¡¡most¡¡important¡¡features
of¡¡flying¡machine¡¡construction¡£¡¡While¡¡in¡¡many
instances¡¡the¡¡propeller£»¡¡at¡¡a¡¡casual¡¡glance£»¡¡may¡¡appear
to¡¡be¡¡identical£»¡¡close¡¡inspection¡¡will¡¡develop¡¡the¡¡fact¡¡that
in¡¡nearly¡¡every¡¡case¡¡some¡¡individual¡¡idea¡¡of¡¡the¡¡designer
has¡¡been¡¡incorporated¡£¡¡Thus£»¡¡two¡¡propellers¡¡of¡¡the¡¡two¡
bladed¡¡variety£»¡¡while¡¡of¡¡the¡¡same¡¡general¡¡size¡¡as¡¡to
length¡¡and¡¡width¡¡of¡¡blade£»¡¡will¡¡vary¡¡greatly¡¡as¡¡to¡¡pitch
and¡¡¡¨twist¡¨¡¡or¡¡curvature¡£
What¡¡the¡¡Designers¡¡Seek¡£
Every¡¡designer¡¡is¡¡seeking¡¡for¡¡the¡¡same¡¡resultthe
securing¡¡of¡¡the¡¡greatest¡¡possible¡¡thrust£»¡¡or¡¡air¡¡displacement£»
with¡¡the¡¡least¡¡possible¡¡energy¡£
The¡¡angles¡¡of¡¡any¡¡screw¡¡propeller¡¡blade¡¡having¡¡a
uniform¡¡or¡¡true¡¡pitch¡¡change¡¡gradually¡¡for¡¡every¡¡increased
diameter¡£¡¡In¡¡order¡¡to¡¡give¡¡a¡¡reasonably¡¡clear
explanation£»¡¡it¡¡will¡¡be¡¡well¡¡to¡¡review¡¡in¡¡a¡¡primary¡¡way
some¡¡of¡¡the¡¡definitions¡¡or¡¡terms¡¡used¡¡in¡¡connection¡¡with
and¡¡applied¡¡to¡¡screw¡¡propellers¡£
Terms¡¡in¡¡General¡¡Use¡£
Pitch¡£The¡¡term¡¡¡¨pitch£»¡¨¡¡as¡¡applied¡¡to¡¡a¡¡screw¡¡propeller£»
is¡¡the¡¡theoretical¡¡distance¡¡through¡¡which¡¡it¡¡would
travel¡¡without¡¡slip¡¡in¡¡one¡¡revolution£»¡¡and¡¡as¡¡applied¡¡to
a¡¡propeller¡¡blade¡¡it¡¡is¡¡the¡¡angle¡¡at¡¡which¡¡the¡¡blades¡¡are
set¡¡so¡¡as¡¡to¡¡enable¡¡them¡¡to¡¡travel¡¡in¡¡a¡¡spiral¡¡path¡¡through
a¡¡fixed¡¡distance¡¡theoretically¡¡without¡¡slip¡¡in¡¡one¡¡revolution¡£
Pitch¡¡speed¡£The¡¡term¡¡¡¨pitch¡¡speed¡¨¡¡of¡¡a¡¡screw
propeller¡¡is¡¡the¡¡speed¡¡in¡¡feet¡¡multiplied¡¡by¡¡the¡¡number¡¡of
revolutions¡¡it¡¡is¡¡caused¡¡to¡¡make¡¡in¡¡one¡¡minute¡¡of¡¡time¡£
If¡¡a¡¡screw¡¡propeller¡¡is¡¡revolved¡¡600¡¡times¡¡per¡¡minute£»
and¡¡if¡¡its¡¡pitch¡¡is¡¡7¡¡ft¡££»¡¡then¡¡the¡¡pitch¡¡speed¡¡of¡¡such¡¡a
propeller¡¡would¡¡be¡¡7x600¡¡revolutions£»¡¡or¡¡4200¡¡ft¡£¡¡per
minute¡£
Uniform¡¡pitch¡£A¡¡true¡¡pitch¡¡screw¡¡propeller¡¡is¡¡one
having¡¡its¡¡blades¡¡formed¡¡in¡¡such¡¡a¡¡manner¡¡as¡¡to¡¡enable
all¡¡of¡¡its¡¡useful¡¡portions£»¡¡from¡¡the¡¡portion¡¡nearest¡¡the
hub¡¡to¡¡its¡¡outer¡¡portion£»¡¡to¡¡travel¡¡at¡¡a¡¡uniform¡¡pitch
speed¡£¡¡Or£»¡¡in¡¡other¡¡words£»¡¡the¡¡pitch¡¡is¡¡uniform¡¡when¡¡the
projected¡¡area¡¡of¡¡the¡¡blade¡¡is¡¡parallel¡¡along¡¡its¡¡full
length¡¡and¡¡at¡¡the¡¡same¡¡time¡¡representing¡¡a¡¡true¡¡sector
of¡¡a¡¡circle¡£
All¡¡screw¡¡propellers¡¡having¡¡a¡¡pitch¡¡equal¡¡to¡¡their
diameters¡¡have¡¡the¡¡same¡¡angle¡¡for¡¡their¡¡blades¡¡at¡¡their
largest¡¡diameter¡£
When¡¡Pitch¡¡Is¡¡Not¡¡Uniform¡£
A¡¡screw¡¡propeller¡¡not¡¡having¡¡a¡¡uniform¡¡pitch£»¡¡but
having¡¡the¡¡same¡¡angle¡¡for¡¡all¡¡portions¡¡of¡¡its¡¡blades£»¡¡or
some¡¡arbitrary¡¡angle¡¡not¡¡a¡¡true¡¡pitch£»¡¡is¡¡distinguished
from¡¡one¡¡having¡¡a¡¡true¡¡pitch¡¡in¡¡the¡¡variation¡¡of¡¡the¡¡pitch
speeds¡¡that¡¡the¡¡various¡¡portions¡¡of¡¡its¡¡blades¡¡are¡¡forced
to¡¡travel¡¡through¡¡while¡¡traveling¡¡at¡¡its¡¡maximum¡¡pitch
speed¡£
On¡¡this¡¡subject¡¡Mr¡£¡¡R¡£¡¡W¡£¡¡Jamieson¡¡says¡¡in¡¡Aeronautics£º
¡¨Take¡¡for¡¡example¡¡an¡¡8¡foot¡¡screw¡¡propeller¡¡having¡¡an
8¡foot¡¡pitch¡¡at¡¡its¡¡largest¡¡diameter¡£¡¡If¡¡the¡¡angle¡¡is¡¡the
same¡¡throughout¡¡its¡¡entire¡¡blade¡¡length£»¡¡then¡¡all¡¡the¡¡porions
of¡¡its¡¡blades¡¡approaching¡¡the¡¡hub¡¡from¡¡its¡¡outer¡¡portion¡¡would
have¡¡a¡¡gradually¡¡decreasing¡¡pitch¡£¡¡The¡¡2¡foot
portion¡¡would¡¡have¡¡a¡¡2¡foot¡¡pitch£»¡¡the¡¡3¡foot¡¡portion¡¡a¡¡3¡
foot¡¡pitch£»¡¡and¡¡so¡¡on¡¡to¡¡the¡¡8¡foot¡¡portion¡¡which¡¡would
have¡¡an¡¡8¡foot¡¡pitch¡£¡¡When¡¡this¡¡form¡¡of¡¡propeller¡¡is
caused¡¡to¡¡revolve£»¡¡say¡¡500¡¡r¡£p¡£m¡££»¡¡the¡¡8¡foot¡¡portion¡¡would
have¡¡a¡¡calculated¡¡pitch¡¡speed¡¡of¡¡8¡¡feet¡¡by¡¡500¡¡revolutions£»
or¡¡4£»000¡¡feet¡¡per¡¡min¡££»¡¡while¡¡the¡¡2¡foot¡¡portion¡¡would
have¡¡a¡¡calculated¡¡pitch¡¡speed¡¡of¡¡500¡¡revolutions¡¡by¡¡2¡¡feet£»
or¡¡1£»000¡¡feet¡¡per¡¡minute¡£
Effect¡¡of¡¡Non¡Uniformity¡£
¡¨Now£»¡¡as¡¡al