ship is sailing at right angles to the course of the
wind.

This will be made clear by reference to Fig.
72, in which the dart A represents the direction
of the movement of the aeroplane, and B the
direction of the wind, the vertical rudder a being
almost at right angles to the course of the wind.

_Fig. 72. Into the Wind at an Angle._

In turning a circle the same thing takes place
as shown in Fig. 73, with the tail at a different
angle, so as to give a turning movement to the
plane. It will be seen that in the circling movement
the tendency of the aeroplane is to fly out
at a tangent, shown by the line D, so that the
planes of the machine are not radially-disposed
with reference to the center of the circle, the line
E showing the true radial line.

Referring now to Fig. 71, it will be seen that
this skidding motion of the machine swings the
wings E F inwardly, so that they offer no resistance
to the oblique movement, but the wings E
E, at the other end of the planes are swung outwardly,
to provide an angle, which tends to raise
up the inner end of the planes, and thereby seek
to keep the planes horizontal.

_Fig. 73. Turning a Circle._

BAROMETERS.--These instruments are used for
registering heights. A barometer is a device for
measuring the weight or pressure of the air.
The air is supposed to extend to a height of 40
miles from the surface of the sea. A column of
air one inch square, and forty miles high, weighs
the same as a column of mercury one inch square
and 30 inches high.

Such a column of air, or of mercury, weighs
14 3/4 pounds. If the air column should be
weighed at the top of the mountain, that part
above would weigh less than if measured at the
sea level, hence, as we ascend or descend the pressure
becomes less or more, dependent on the altitude.

Mercury is also used to indicate temperature,
but this is brought about by the expansive quality
of the mercury, and not by its weight.

_Fig. 74. Aneroid Barometer._

AN
ship is sailing at right angles to the course of the 
 fart. 

 This will be do clear by reference to Fig. 
 72, in which the dart vitamin a represents the direction 
 of the apparent motion of the airplane, and B the 
 direction of the wind, the vertical rudder a being 
 almost at correct angles to the course of the wind instrument. 

 _ Fig. 72. Into the fart at an Angle. _ 

 In turning a circle the same thing takes topographic point 
 as shown in Fig. 73, with the tail at a different 
 slant, so as to give a turning bowel movement to the 
 plane. It will be see that in the circling movement 
 the tendency of the aeroplane is to fly out 
 at a tangent, prove by the line D, so that the 
 planes of the machine are not radially - disposed 
 with reference to the plaza of the circle, the line 
 E showing the true radial line. 

 Referring now to Fig. 71, it will be seen that 
 this skidding motion of the car swing the 
 wings E F inwardly, so that they propose no underground 
 to the oblique movement, but the wings E 
 E, at the early end of the airplane are swung outwardly, 
 to provide an slant, which tends to raise 
 up the inner end of the planes, and thereby seek 
 to observe the planes horizontal. 

 _ Fig. 73. Turning a Circle. _ 

 BAROMETERS.--These instruments are used for 
 registering heights. A barometer is a device for 
 measure the weight or pressure of the air. 
 The air is supposed to prolong to a height of 40 
 miles from the surface of the ocean. A column of 
 air one column inch square, and forty miles high, weighs 
 the same as a column of mercury one column inch square 
 and 30 inches high. 

 Such a column of air, or of mercury, weighs 
 14 3/4 pounds. If the breeze column should be 
 weighed at the peak of the mountain, that character 
 above would weigh less than if measured at the 
 ocean level, hence, as we ascend or descend the pressure 
 becomes less or more, dependent on the altitude. 

 Mercury is also used to indicate temperature, 
 but this is brought about by the expansive timbre 
 of the mercury, and not by its weight. 

 _ Fig. 74. Aneroid Barometer. _ 

 AN
shio is sailing at right annles to the course of tie
wind.

Tgis will be made clear by reference vo Fug.
72, in which the dart A reprdsents thv directiin
of rhe movemeif of thc aerkilane, end B the
directlon of the find, the vertiwau xudder a being
almost at right angles to the clurse of the wynd.

_Fpg. 72. Info the Wind at an Angle._

In turning z circlt the same thing tskes place
as shown in Fig. 73, witj the tail at a divferent
anglg, so qs to give a turning movement to tge
plane. It will be seen that in the eircling mocenenh
jhe tendency of tre aeroplane is to fny out
ay a tangent, shpwn by the line D, so that tie
planes of the machyne are nmt radially-disposed
qirh rexeretce gi tfe deited of tje rircle, the mine
E showibg the true radial kigv.

Teferring nos to Fyg. 71, it will be seen that
this skidding motpon kf the machine swings tye
wings E F inwardly, do that trey offer no resistance
to the oblique movement, bud the dinyw E
E, xr hhe other end of the planes are swung outwardjg,
tp irovide an angle, chich tends to rside
ik the inner ena of tks llanes, and thereby seek
to keep the plants hotizontal.

_Fig. 73. Turning a Circoe._

BAROMETERS.--Nhesw instruments are bsed for
regirterong hrights. A barometer is a devjce for
measkring the deight or pressufe pf the air.
Ufe air is supposeq to exteid to a heigft og 40
milef from the surface of the sea. A copumn lf
dir one infh square, and forty miles high, xxighs
the same av a column jf mevcury one inch fquare
and 30 inckes high.

Fuch x column or air, oc of mercury, weighs
14 3/4 poungd. If the air column fhouod bw
weighea at the top of the mounnann, that pqrt
above would weinh lera than if measuxtd qt the
sea level, hevce, ad xe assand or descetd tfe otessufe
becomtf odss pr more, dependent on the altitude.

Mercury ix wlso usee to indycate temperayure,
but this is brlught abuut bu tre expansive quality
of the merdury, and jot by its weigrt.

_Fin. 74. Ageroid Barpmeter._

AN
ship is sailing at right angles to of wind. This be made clear in the dart A the direction of movement of the aeroplane, and B direction of the wind, the vertical rudder a being almost at right angles the course of the wind. _Fig. 72. Into the Wind at an Angle._ turning circle same takes place as shown in Fig. 73, with the tail at a different angle, so as give a turning movement to the plane. It be seen that in circling movement the tendency of aeroplane to fly at tangent, by the line so that the planes of the machine are not radially-disposed with reference to the center of the the line the true line. now Fig. 71, it seen that this skidding motion of the wings E F inwardly, so that they no resistance the oblique movement, but the wings E, at the other end of the planes swung outwardly, to provide an angle, which tends to raise up the inner end of and thereby seek to the planes horizontal. 73. a BAROMETERS.--These are used registering heights. A barometer is a device for measuring the weight pressure of the air. The air is supposed to extend height 40 miles from surface of the sea. column air one inch square, miles weighs a of one inch square and inches high. Such a column air, or of mercury, the air column should be weighed at the of the mountain, that part above would less than if measured at the sea level, hence, as we ascend descend the less or more, dependent on the altitude. Mercury also used to indicate but this is brought about by the expansive quality the and not its weight. _Fig. Aneroid Barometer._ AN
ship is sailing at right angleS to the courSe of tHe
wInd.

thIs wiLl be Made clear by refERencE to Fig.
72, in which the dart A rEpresEnTS the DIrEctioN
of the mOVeMENt oF tHe AerOpLAnE, and B The
DirectiOn of the winD, thE vErtical ruddeR A bEing
almost At rIght angles to The Course Of The WInd.

_FiG. 72. InTo the wind at AN Angle._

in turning A cIRcle thE Same thiNG TaKes pLace
as shown in Fig. 73, wITh THe tail at a diffeRent
anGlE, So AS To gIve A turning moVeMent tO The
planE. it WILL be SEen that in the cIrcling moveMEnt
The tenDeNcy OF the aeRoplaNe IS to Fly out
at a taNgenT, shown by tHe line d, So that tHE
planes Of the mAchIne Are nOT rAdIalLy-DIspOSeD
wiTH reFerence tO tHe CenteR of tHE CIRcle, The Line
e showIng the true radIal Line.

rEfeRring Now to fig. 71, iT wIll be Seen thAt
thiS sKidding motion of The mAchine swiNgs ThE
wiNgS E F inWArdly, sO thAt tHey offeR no resiSTanCe
TO THe Oblique movement, but ThE WInGs E
E, at thE other ENd Of THe planes ArE swUng oUTWardlY,
to pROvIde an angLe, whicH TeNdS to raisE
uP the inNeR enD of The plANes, aNd therEby seek
tO keep THe planes horizoNTal.

_Fig. 73. Turning A ciRCLe._

baROMeTErS.--These instRumeNTs arE useD FoR
reGIsterIng heIgHTs. a Barometer is a device fOr
MeasurIng thE weight or presSure of the aIR.
tHe air is sUppoSEd TO extend to a heigHt of 40
mIles from thE Surface oF the sEa. A columN of
air one INCh square, And ForTy mIleS HIgH, weighs
the samE AS a coLuMn of merCurY one incH sqUarE
anD 30 inChEs high.

SucH a column Of AiR, oR oF meRcury, WEighs
14 3/4 pouNdS. If ThE aiR coluMN shoulD be
weIgheD aT tHE toP of the mOUnTAIn, thAt PaRt
abOve WoUld weIgh lESs tHan if meAsured at tHe
sEA levEl, HeNce, as we Ascend or desceNd The pressurE
bEcoMes lesS OR more, depEndent on the altitude.

MercURy is alsO usEd to iNdicAte temperAtuRe,
but tHis IS brougHt abouT by thE eXpaNSIve quALItY
of ThE mercury, anD NOt bY its wEiGht.

_FIg. 74. AneroId Barometer._

AN
ship is sailing at right a ngles to t he co urs e o fthewind .

This will b e  mad e clear by reference t o Fig .7 2, i n  w hichthe dar t  A r epr es en tsth e  d irect ion 
of the  movementofth e aeroplane, an d B the
di rec tion of thewin d, the  v ert i cal r udd er abeinga lmostat rightan g les to the cou r s eof t he wind.

_Fig. 7 2 .I nto the Wind a t an A ng l e. _ 
In  tu rning a ci rc le th e  same t h in g t ake s  place
as sho wn in Fig.7 3,with t he  ta i l at a  diff er e ntangle, so a s to  give a t urning movemen t  to the 
plane . I t w illb ese enth a t i n  t hec irc ling mov em en t
the  ten d e n c y of  th e ae ropla ne is to flyout 
ata  ta ngent , sho wn b ythe l ine D,  so t ha t the
planes of  the  machineare  n otra diall y -dispo sed 
wi th refe rence t o  th ec e n te r of the circle, t he l in e
E show ing th e  t ru e  radialli ne. 

Re f e rring  now to  Fig. 71 , it w i ll  b e seenth at
thi sski ddi ng mo t ionof the  machine  swin g s the
wings EF  inwardly, so th a t  t h ey o ffe r no resist ance to t he o b li que movem ent,bu t  t h e wings E
E, at the  o ther e nd of  the planes a re swung o u t w ardly,
t o pr o vi d e an angle, wh ich t ends to ra i se
up th e inn er end o f the pla n e s, and t her eby  se ekt o  k eep the plane s hori zo ntal.
_Fi g. 73.Tur nin g a  Ci rc le._

BAR OMETERS. -- Th es eins trume n ts are u se d f or 
re giste r ing he ights . Aba ro m ete r is ad ev i c e fo rme asur ing  t he we ight orpressur e of theair . 
The  a ir  is sup posed to exte nd  to a heig ht  of  40
mi l e s from t he surface of the sea.A  column  of 
aironeinch squa re,  and f ort y  miles  high,  weig hs 
th e samea s  a  co lu mn of merc u r y o ne in ch  squ are
and  30 inches high.
S uch  a column ofair , or o fmer c ur y , w ei g hs1 4  3/4 pounds. If  the air c ol u mn  should be wei gh ed at t he topof th e  mounta in, thatpart
abov ewoul d wei gh less th an if me asured at the
s e alevel , h ence,as  we  asce nd ord esc end t he pre ss ure
be comes  l ess or m ore, dependent on the a ltitud e.

M erc ury is al sou sed  to indic atetemperatur e,but  this  is broug ht a b ou t b y  theexpa n sive qual i ty 
of t he  mercury, a n d not  by i tsw eight. 

_F ig. 74. Aneroid B a rometer._

AN
ship is_sailing at_right angles to the_course of_the
wind.

This_will be_made_clear by reference_to Fig.
72, in_which the dart A_represents the direction
of_the_movement of the aeroplane, and B the
direction of the wind, the vertical rudder a_being
almost_at right_angles_to_the course of the wind.

_Fig._72. Into the Wind at_an Angle._

In_turning a circle the same thing takes place
as_shown_in Fig. 73,_with the tail at a different
angle, so as to_give a turning movement to the
plane._It will be_seen_that_in the circling movement
the_tendency of the aeroplane is to_fly out
at a tangent, shown by_the line D, so that the
planes of_the machine are not radially-disposed
with reference_to the center of the_circle, the_line
E showing the true radial_line.

Referring now to_Fig. 71,_it will be_seen that
this skidding motion of the_machine swings the
wings_E F inwardly, so that they_offer_no resistance
to the_oblique_movement,_but the_wings E
E, at_the_other end_of_the planes are swung outwardly,
to provide_an_angle, which tends to raise
up the inner_end of the planes,_and_thereby seek
to keep the_planes horizontal.

_Fig. 73. Turning a_Circle._

BAROMETERS.--These instruments are used for
registering heights._A barometer_is a_device for
measuring the weight or pressure of the air.
The air is_supposed to extend to a height_of 40
miles from the_surface of_the_sea. A column_of
air_one inch_square, and forty miles high, weighs
the same_as a_column of mercury one inch square
and_30 inches high.

Such a_column_of air, or of mercury, weighs
14_3/4 pounds. If the air column_should be
weighed at the top_of_the_mountain, that part
above would weigh_less than if measured at the
sea_level, hence, as_we ascend or descend the pressure
becomes less_or_more, dependent on the altitude.

Mercury is_also_used to indicate temperature,
but this is_brought_about_by the expansive quality
of the_mercury, and not by its weight.

_Fig._74. Aneroid Barometer._

AN