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much more prevalent than one might suppose； even
among men who； under other conditions； are cool and
confident in their actions。
There is something in the sensation of being suddenly
lifted from the ground； and suspended in the air that is
disconcerting at the start； but this will soon wear off if
the experimenter will keep cool。 A few successful flights
no matter how short they may be； will put a lot of
confidence into him。
Make Your Flights Short。
Be modest in your initial flights。 Don't attempt to
match the records of experienced men who have devoted
years to mastering the details of aviation。 Paulhan；
Farman； Bleriot； Wright； Curtiss； and all the rest of
them began； and practiced for years； in the manner here
described； being content to make just a little advancement
at each attempt。 A flight of 150 feet； cleanly and
safely made； is better as a beginning than one of 400
yards full of bungling mishaps。
And yet these latter have their uses； provided the
operator is of a discerning mind and can take advantage
of them as object lessons。 But； it is not well to invite
them。 They will occur frequently enough under the
most favorable conditions； and it is best to have them
come later when the feeling of trepidation and uncertainty
as to what to do has worn off。
Above all； don't attempt to fly too high。 Keep within
a reasonable distance from the groundabout 25 or 30
feet。 This advice is not given solely to lessen the risk
of serious accident in case of collapse； but mainly because
it will assist to instill confidence in the operator。
It is comparatively easy to learn to swim in shallow
water； but the knowledge that one is tempting death in
deep water begets timidity。
Preserving the Equilibrium。
After learning how to start and stop； to ascend and
descend； the next thing to master is the art of preserving
equilibrium； the knack of keeping the machine perfectly
level in the airon an 〃even keel；〃 as a sailor would
say。 This simile is particularly appropriate as all aviators
are in reality sailors； and much more daring ones
than those who course the seas。 The latter are in craft
which are kept afloat by the buoyancy of the water；
whether in motion or otherwise and； so long as normal
conditions prevail； will not sink。 Aviators sail the air
in craft in which constant motion must be maintained in
order to ensure flotation。
The man who has ridden a bicycle or motorcycle
around curves at anything like high speed； will have a
very good idea as to the principle of maintaining equilibrium
in an airship。 He knows that in rounding curves
rapidly there is a marked tendency to change the direction
of the motion which will result in an upset unless
he overcomes it by an inclination of his body in an opposite
direction。 This is why we see racers lean well
over when taking the curves。 It simply must be done
to preserve the equilibrium and avoid a spill。
How It Works In the Air。
If the equilibrium of an airship is disturbed to an
extent which completely overcomes the center of gravity
it falls according to the location of the displacement。
If this displacement； for instance； is at either end the
apparatus falls endways； if it is to the front or rear； the
fall is in the corresponding direction。
Owing to uncertain air currentsthe air is continually
shifting and eddying； especially within a hundred feet or
so of the earththe equilibrium of an airship is almost
constantly being disturbed to some extent。 Even if this
disturbance is not serious enough to bring on a fall it
interferes with the progress of the machine； and should
be overcome at once。 This is one of the things connected
with aerial navigation which calls for prompt；
intelligent action。
Frequently； when the displacement is very slight； it
may be overcome； and the craft immediately righted by
a mere shifting of the operator's body。 Take； for illustration；
a case in which the extreme right end of the
machine becomes lowered a trifle from the normal level。
It is possible to bring it back into proper position by
leaning over to the left far enough to shift the weight
to the counter…balancing point。 The same holds good as
to minor front or rear displacements。
When Planes Must Be Used。
There are other displacements； however； and these are
the most frequent； which can be only overcome by manipulation of
the stabilizing planes。 The method of procedure
depends upon the form of machine in use。 The
Wright machine； as previously explained； is equipped
with plane ends which are so contrived as to admit of
their being warped （position changed） by means of the
lever control。 These flexible tip planes move simultaneously；
but in opposite directions。 As those on one end
rise； those on the other end fall below the level of the
main plane。 By this means air is displaced at one point；
and an increased amount secured in another。
This may seem like a complicated system； but its
workings are simple when once understood。 It is by
the manipulation or warping of these flexible tips that
transverse stability is maintained； and any tendency to
displacement endways is overcome。 Longitudinal stability
is governed by means of the front rudder。
Stabilizing planes of some form are a feature； and a
necessary feature； on all flying machines； but the methods
of application and manipulation vary according to the
individual ideas of the inventors。 They all tend； however；
toward the same endthe keeping of the machine
perfectly level when being navigated in the air。
When to Make a Flight。
A beginner should never attempt to make a flight
when a strong wind is blowing。 The fiercer the wind；
the more likely it is to be gusty and uncertain； and the
more difficult it will be to control the machine。 Even
the most experienced and daring of aviators find there
is a limit to wind speed against which they dare not
compete。 This is not because they lack courage； but
have the sense to realize that it would be silly and useless。
The novice will find a comparatively still day； or one
when the wind is blowing at not to exceed 15 miles an
hour； the best for his experiments。 The machine will be
more easily controlled； the trip will be safer； and also
cheaper as the consumption of fuel increases with the
speed of the wind against which the aeroplane is forced。
CHAPTER XIII。
PECULIARITIES OF AIRSHIP POWER。
As a general proposition it takes much more power to
propel an airship a given number of miles in a certain
time than it does an automobile carrying a far heavier
load。 Automobiles with a gross load of 4；000 pounds；
and equipped with engines of 30 horsepower； have travelled
considerable distances at the rate of 50 miles an
hour。 This is an equivalent of about 134 pounds per
horsepower。 For an average modern flying machine；
with a total load； machine and passengers； o