, I am
not much of an airplane man."

"Well," said Paul, "you know, sir, that it is far more difficult to
drive an airplane than to guide an automobile, not merely because you
have two steering-gears or rudders to take care of, one for sidewise
and the other for up-and-down travel, but also because there are
movable planes in the wings of the machine, which have to be worked to
tip or 'bank' it when making a turn or to keep it on an even keel when
a gust of wind strikes it. The 'rudder' is the vertical plane at the
tail of the machine, and is used for steering sideways, while the
'elevators' are the two horizontal movable planes just below the
rudder, which are used for steering up and down. Similar planes to the
latter, one situated in the back edge of each upper wing, are called
'ailerons,' and one or the other is raised or depressed according to
whether the aviator wishes to bank to the right or left.

"The driver of an automobile has nothing to do but watch his
steering-wheel, and be ready to touch a pedal when he wishes to slow up
or go faster or stop. If he makes a curve he does not have to bank his
machine owing to his comparatively slow speed; but the aviator,
traveling much faster through the air, must do this, bringing his
airplane to a steep angle if he makes a very short turn. If he does
not calculate just right, he is likely to turn upside down and meet
this death in a nasty fall.

"While the careful automobilist can always see the road in front of him
and avoid rough spots or obstacles before he reaches them, the aviator
cannot do this. It is true that he can see another airplane if it gets
in his way, or a church steeple when he is flying low; but his greatest
dangers are in the clear air itself, where they cannot be detected. He
may suddenly drop into a 'hole,' which is really a downward current of
air, or he may get a terrific bump when he strikes a rising current. A
freakish whim of the winds may unexpectedly take away the air support
from under one of the wings, and he will lurch and dip sharply to one
side."

"And I suppose sometimes lose all control?" said Mr. Giddings.

"Yes, sir; that has very often happened," put in John. "A flyer friend
of mine took a nasty tumble that way near Cleveland last year, breaking
three ribs. It's a wonder he wasn't killed."

"The pilot is blind to these pitfalls," went on Paul. "He must control
his machine largely by intuition and the sense of feeling