The mirror., 1918-06-13
T is a curious phenomenon
this growth into our
social and national life of

NISS8SNH -GnlS STOWtu luVO our
HSKNl social and national life of
tA-Al some new invention, with
out our really understanding any
thing about it. Telephones, elec-
trio lights, the storage battery, the
common desk fan. and a hundred
other everyday adaptions of the
discoveries of science get inter-
woven into our daily affairs with
out our having more than the most
elementary understanding of their
how.
And now, slowly, with it's diff
ficulty in making headway against
the inertia of public sentiment in
peace time, and much more rapid
ly with the demands of war, the
airplane is forcing its way into our
vision. Already it carries passen-
gers; it is soon to carry mails; the
next ten years will see it displace
more than one ferry, and there
seems small doubt that, in it's ma
rine form, it will get the love of
many a waterman who has hitherto
found outlet for his energy and
his love of matters marine in the
motor boat.
Yet not one man in a thousand
understands anything more about
an airplane, or how it is built or
why it is SO built, than that it pos
sesses some surfaces, an engine and
a propeller.
Why are some airplanes fast and
others slowa Why do some ap-
pear squat and fat, and others
wide and slenderg Why can some
climb up high very fast and others
but crawl aloft? Why are some
built with two wings" (the pilot
never calls them soD and others
with four? Why is the top wing
set forward of the bottom ones
Why do their centers sink lower
than their edgesg Why is the
lower wing somewhat behind the
top one2 Why isn't the body of
the machine under both wings to
give an unobstructed view down,
or on top of both wings to give an
unobstructed view alofts Why is
a side slip. a nose dive, a spiral,
a glide, an accidents
Ask yourself, ask your friend,
ask almost every one whose life
does not bring him intimately in
touch with aeronautics, and see
that, like the telephone, we all &C
cept the air boat or the airplane, as
fact, without in the least under
standing that it is a factl
When, ten years ago (so short a
time for the progress made!), the
first tentative airplanes were built,
any machine was good machine
which got into the air and stayed
there. Now no machine is a good
machine just because it will fly,
any more than any automobile is a
good automobile because it will
run. The airplane of today must
function according to its design,
or it is no good. Doubtless, the
first savages to dig out a log found
the resulting boat a good boat. but
today the hull is most carefully de-
signed for size. speed, resistance.
carrying capacity, beauty. and
efficiency, and if it doesn't meet its
designers hopes and plans it's a
poor hull.
So with the air boat. But like
its big brother of the water, the
air boat is not, as yet, anything
but a compromise. No one has
as yet designed a water going
structure which has the maximum
of speed, safety, carrying capacity,
and beauty, all at once.
And no one has as yet designed
any sort of flying structure which
is anything but compromise.
To understand why, it is neces-
sary to know why an airplane flies
at all. When surface is inclined