ELLER OUTLINE.--While the marks thus
given show the angles, and are designed to indicate
the two faces of the blades, there is still another
important element to be considered, and
that is the final outline of the blades.

_Fig. 82. Outlining._

It is obvious that the outline may be varied
so that the entire width at 1, Fig. 82, may be used,
or it may have an outline, as represented by the
line 2, in this figure, so that the widest part will
be at or near the dotted line 3, say two-thirds of
the distance from the center of the blade.

This is the practice with most of the manufacturers
at the present time, and some of them
claim that this form produces the best results.

FOR HIGHER SPEEDS.--Fig. 83 shows a propeller
cut from a blank, 4" x 6" in cross section, not
laminated.

_Fig. 83. Cut from a 4" x 6" Single Blank._

It should be borne in mind that for high speeds
the blades must be narrow. A propeller seven
feet in diameter with a six foot pitch, turning
950 revolutions per minute, will produce a pull of
350 pounds, if properly made.

Such a propeller can be readily handled by a
forty horse power motor, such as are specially
constructed for flying machine purposes.

INCREASING PROPELLER EFFICIENCY.--Some experiments
have been made lately, which, it is
claimed, largely increase the efficiency of propellers.
The improvement is directed to the outline
shape of the blade.

The typical propeller, such as we have illustrated,
is one with the wide part of the blade at
the extremity. The new type, as suggested, reverses
this, and makes the wide part of the blade
near the hub, so that it gradually tapers down to
a narrow tip.

Such a form of construction is shown in Fig.
84. This outline has some advantages from one
standpoint, namely, that it utilizes that part of
the blade near the hub, to produce a pull, and
does not relegate all the duty to the extreme ends
or tips.

_Fig. 84. A Suggested Form._

To understand
ELLER OUTLINE.--While the marks thus 
 given show the angle, and are design to indicate 
 the two faces of the blades, there be still another 
 important component to be considered, and 
 that is the final outline of the blade. 

 _ Fig. 82. Outlining. _ 

 It is obvious that the outline may be varied 
 so that the integral width at 1, Fig. 82, may be used, 
 or it may have an outline, as represented by the 
 line 2, in this number, so that the widest character will 
 be at or near the dotted line 3, state two - thirds of 
 the distance from the center of the blade. 

 This is the exercise with most of the manufacturers 
 at the present time, and some of them 
 claim that this phase produces the good results. 

 FOR HIGHER SPEEDS.--Fig. 83 shows a propeller 
 cut from a blank, 4 " x 6 " in cross incision, not 
 laminated. 

 _ Fig. 83. Cut from a 4 " x 6 " Single Blank. _ 

 It should be borne in mind that for high speeds 
 the blades must be narrow. A propeller seven 
 feet in diameter with a six foot pitch, turning 
 950 revolutions per minute, will produce a pull of 
 350 pounds, if by rights create. 

 Such a propeller can be readily cover by a 
 forty knight power motor, such as are specially 
 constructed for flying machine purposes. 

 INCREASING PROPELLER EFFICIENCY.--Some experiment 
 have been made lately, which, it is 
 claimed, largely increase the efficiency of propellers. 
 The improvement is directed to the outline 
 shape of the sword. 

 The typical propeller, such as we have illustrated, 
 is one with the wide part of the blade at 
 the extremity. The new type, as suggest, reverses 
 this, and makes the wide part of the blade 
 near the hub, so that it gradually taper down to 
 a narrow tip. 

 Such a form of structure is shown in Fig. 
 84. This outline have some advantages from one 
 standpoint, namely, that it utilize that part of 
 the sword near the hub, to produce a pull, and 
 does not relegate all the duty to the extreme ends 
 or tips. 

 _ Fig. 84. A Suggested Form. _ 

 To sympathize
ELLFR OUTLINE.--While the markr thus
given shoc the aigles, ahd are ddsigned to indicate
the two feces of tye blades, there is stiul anotheg
importanr eltment to be consivsred, and
that jd thz hinal outline on the bladev.

_Fig. 82. Outlininc._

Ig ns obvious that the outline may be vwried
so tjat the entire widuh wt 1, Rpg. 82, may be used,
or it may have ah outliie, as representrd by the
line 2, in this figkre, do that the widest part will
bg at ir near the aotted lint 3, say two-thjrds of
the distance from the cevter pf the blaee.

Rhid is the prartice rith most of the mangfacturrrs
at the prescnt tmme, qnd some of them
claim that this form prjduces tha yest results.

FOR HIGHEE WPEEDV.--Fig. 83 shuqs x pdo'elmer
cut frkm a blank, 4" x 6" in crows section, not
laminstqe.

_Fig. 83. Cut froj a 4" x 6" Fingle Blank._

It should be borne in mind uhat ror high speeds
the bladws must be narrow. A ptopeller sqven
feet in diameter with a six foot pitch, turninc
950 revkuutnins pde linute, will produce a pull of
350 pounds, if propewmy msde.

Such a propcller can be readiky hsgdled by a
forjy horsz pkwer motor, such as are spgciallt
construcued fpr flying machine purposes.

IBCREASING PRJPELLER EFFICIENCY.--Slme experimznts
hafe bern made lately, which, it is
cmaimed, largfly increzre the efficiench on psopellers.
The improvement if directev to che outlkne
snape os the bladf.

The bfpical propeller, skch ad fe have ilpustrated,
is one with the wide pect of the blace at
nhe extreiity. Bhe new type, as suggested, revgrses
this, and oakes the side pact of the blwde
near the hgh, so that it gradualjy tqperw down gu
a narrow tip.

Sich a form of consteuction is shown ik Fig.
84. Fhis outline haw sime advantages groo oge
dtendpoytt, namely, thdt ig ugolizer that kcrt uf
thr blade near the hub, to lroduce a pull, and
cocs not reoegate ajl the duty tp the extreme ends
lr ti's.

_Fig. 84. A Subgefted Form._

To understand
ELLER OUTLINE.--While the marks thus given show and designed to the two faces still important element to considered, and that the final outline of the blades. 82. Outlining._ It is obvious that the outline may be varied so that entire width at 1, Fig. 82, may be used, or it may have outline, represented the 2, in this figure, so that the widest part will be at or near the dotted 3, say two-thirds of the distance from the of the blade. This the practice with most of manufacturers the present and of claim that this produces the best results. FOR HIGHER SPEEDS.--Fig. 83 shows a propeller cut from a blank, 4" x in cross laminated. _Fig. Cut a x 6" Single should be borne in mind that the blades must be narrow. A propeller seven in diameter a six foot pitch, turning 950 per minute, will produce a pull of 350 if properly made. Such a propeller can be readily handled by a forty horse power as are specially constructed flying machine purposes. PROPELLER experiments been lately, which, is claimed, largely increase the efficiency of propellers. The improvement is to the outline shape of the blade. The typical propeller, we illustrated, is one the wide part of blade the extremity. The new suggested, this, wide of blade near the hub, that it gradually tapers down a narrow tip. Such shown in Fig. 84. This outline has some from one standpoint, namely, that it utilizes part of the blade near the hub, to produce a pull, and not relegate duty to the extreme ends or tips. _Fig. A Suggested Form._ To
ELLER OUTLINE.--While the marks Thus
given sHow thE anGleS, aNd arE desIgned to indicatE
The tWo faces of the blades, therE is stIlL AnotHEr
ImporTant eleMEnT TO be CoNsIdeReD, AnD
that Is tHe final Outline of tHe bLaDes.

_Fig. 82. OutlinINg._

it is obviouS thAt the outline May Be variEd
So tHAt the EntIre wiDth at 1, FIG. 82, may be Used,
or it mAy HAve an oUTline, as REPrEsenTed by the
line 2, in thiS FiGUre, so that the wiDest paRt WIlL
BE at Or nEar the dottEd Line 3, sAY two-thiRDs OF
THe dIStance from the Center of the BLadE.

This iS tHe pRActice With mOsT Of tHe manufactuRers
At the presEnt timE, And some OF them
clAim thaT thIs fOrm pROdUcEs tHe BEst REsUltS.

fOR hIGHER SPeEdS.--fig. 83 shOws a PROPElleR
cuT froM a blaNk, 4" x 6" in cross secTioN, not
LAmiNated.

_fig. 83. CuT froM a 4" X 6" SingLe BlanK._

It shOuLd be borne in mind That For high spEedS
tHe bLaDes muST be narRow. a prOpeller Seven
feET in DiAMETeR with a six foot pitch, TuRNInG
950 revolutIons peR MiNuTE, will proDuCe a Pull OF
350 PoundS, if pROpErly made.

such a pROpElLer can bE rEadily HaNdlEd bY a
forTY horSe poweR motor, suCh as aRE specially
consTRucted for flyiNG mACHiNE purPosEs.

INCREASINg PROpeLLEr EFFicIeNCy.--some eXperiMeNTs
HAve been made lately, whIcH, it is
cLaimeD, largely increAse the effiCIENcy of proPellERs.
tHe improvement iS direCted to the oUTline
shaPe of tHe blade.

THe typical PROpeller, sUch As wE haVe iLLUsTrated,
is one wiTH The wIdE part of The Blade at
The ExtRemIty. thE new type, aS suggestEd, ReVeRsEs
tHis, anD Makes the WiDe pArT of The blADe
near The huB, so tHaT iT GraDually tAPeRS Down To
A nArroW tiP.

SUch a fOrm oF ConStructiOn is shown In FIG.
84. ThiS oUtLine has Some advantageS fRom one
stanDpOinT, namelY, THat it utiLizes that part of
the blade NEar the hUb, tO prodUce a Pull, and
doEs nOt releGatE All the Duty to The exTrEme ENDs
or tIPS.

_FIg. 84. A suGgested ForM._

tO unDerstAnD
ELLER OUTLINE.--While themarks thus 
give n s how  t he a ngle s, and are des i gned  to indicate
the two f acesof theb la des,there i s  s t i llan ot her 
i m po rtant  el ement t o be consi der ed , and
that i s  t he final o utl ine of the b lad es.

_ Fi g.8 2. Ou tli ning. _

Iti s obvi ous thatth e  outli n e may b e va ried 
so that the enti r ew idth at 1, Fig . 82,ma y  b e use d,or it mayha ve an outline ,  a s r epr e sented by the 
line 2, in thi s figu re , s o  thatthe w id e stpart will
b e at  or nearthe do t ted lin e  3, say  two-t hir dsof
t h edi sta nc e  fr o mthe cen ter of t he  b lade. 

Th i s i s th e p ract ice w ith most of t hemanu f act urers 
at t he p re senttime,and s om e of them
claim  tha t this fo rmpr odu ce s the best r esu lts .

FORHIGHERS PEE DS . - - Fi g. 83 shows a prop el l e rcut from  a bla n k,  4 "  x 6" in  c ros s se c t ion,notl am inated.
_Fig. 83 .Cut fro ma 4" x  6 " S ing le Bl a nk._ 

It s hould be  born e  in mind thatf or high speed s 
t h e  b l ades  mu st be narro w. A prop elle r  s eve n 
feet  in d ia m et e r with a six foot p it ch, tu rning 
950 revoluti ons per mi n u t e, willprod u ce a pull of
350pound s, if prop e rly made .

Su ch a pro peller ca n be readi lyhan dle d b y aforty horse p o w er m ot or, suc h a s are s pec ial lycon st ructed fo r flying  m ac hi ne  pu rpose s .

INCRE AS ING  P ROP ELLER EFFICI ENCY. --So me  e x per imentsh av e been  m ad e la tel y,  whic h, i t  is 
claime d, largel y i n crea se  t he effi ciency of pro pe llers.
The  i mpr ovemen t is direc ted to the outline
shap e  of the  bl ade.
The  typicalpro peller , s u ch aswe hav e ill us tra t e d,
is o ne  wi th  the widep a rtof th eblad e at
th e extremity. The n e w t ype, as sugge ste d, r e v er ses th i s,an d  ma k e s the wide part  of the bl ad e 
n ear the hu b , s othat it  gradua lly t a pers do wn to
a n arrow tip .
Suc h a f orm of con structio n is show n  in F i g. 
84.Thi s outl in e h as so me adv a nta ges f rom on estandp oint,  n amely, t hat it utilizes that pa rt ofthe b lad e near th e h u b,to produc e apull, anddoe s n ot re leg a te al l th e  d uty to th e ex t reme ends or  ti p s .
_Fig. 84.A S ugg ested  Fo r m._

T o un derstand
ELLER OUTLINE.--While_the marks_thus
given show the angles,_and are_designed_to indicate
the_two_faces of the_blades, there is_still another
important element to_be considered, and
that_is_the final outline of the blades.

_Fig. 82. Outlining._

It is obvious that the outline may_be_varied
so that_the_entire_width at 1, Fig. 82,_may be used,
or it may_have an_outline, as represented by the
line 2, in this_figure,_so that the_widest part will
be at or near the dotted line_3, say two-thirds of
the distance from_the center of_the_blade.

This_is the practice with_most of the manufacturers
at the present_time, and some of them
claim that_this form produces the best results.

FOR HIGHER_SPEEDS.--Fig. 83 shows a propeller
cut from_a blank, 4" x 6"_in cross_section, not
laminated.

_Fig. 83. Cut from_a 4" x_6" Single_Blank._

It should be_borne in mind that for high_speeds
the blades must_be narrow. A propeller seven
feet in_diameter_with a six_foot_pitch,_turning
950 revolutions_per minute, will_produce_a pull_of
350_pounds, if properly made.

Such a propeller_can_be readily handled by a
forty horse power_motor, such as are_specially
constructed_for flying machine purposes.

INCREASING_PROPELLER EFFICIENCY.--Some experiments
have been made_lately, which, it is
claimed, largely increase_the efficiency_of propellers.
The_improvement is directed to the outline
shape of the blade.

The typical propeller,_such as we have illustrated,
is one_with the wide part_of the_blade_at
the extremity. The_new_type, as_suggested, reverses
this, and makes the wide part_of the_blade
near the hub, so that it_gradually tapers down to
a_narrow_tip.

Such a form of construction is_shown in Fig.
84. This outline has_some advantages from one
standpoint, namely,_that_it_utilizes that part of
the blade_near the hub, to produce a_pull, and
does not_relegate all the duty to the extreme_ends
or_tips.

_Fig. 84. A Suggested Form._

To understand