red miles an hour, and "That's all
right!" exclaims the Pilot. "And very useful, too, in a fog or a cloud,"
he reflects, for then he can safely leave the angle of the glide to
itself, and give all his attention, and he will need it all, to keeping
the Aeroplane horizontal from wing-tip to wing-tip, and to keeping it
straight on its course. The latter he will manage with the rudder,
controlled by his feet, and the Compass will tell him whether a straight
course is kept. The former he will control by the ailerons, or little
wings hinged to the tips of the planes, and the bubble in the
Inclinometer in front of him must be kept in the middle.

A pilot, being only human, may be able to do two things at once, but
three is a tall order, so was this pilot relieved to find the Design not
at fault and his craft a "natural glider." To correct this nose-heavy
tendency when the Engine is running, and descent not required, the
centre of Thrust is arranged to be a little below the centre of Drift
or Resistance, and thus acts as a counter-balance.

But what is this stream of bad language from the Exhaust Pipe,
accompanied by gouts of smoke and vapour? The engine, now revolving
at no more than one-tenth its normal speed, has upset the proportion
of petrol to air, and combustion is taking place intermittently or
in the Exhaust Pipe, where it has no business to be. "Crash, Bang,
Rattle----!----!----!" and worse than that, yells the Exhaust, and the
Aeroplane, who is a gentleman and not a box kite,[13] remonstrates with
the severity of a Senior Officer. "See the Medical Officer, you young
Hun. Go and see a doctor. Vocal diarrhoea, that's your complaint, and a
very nasty one too. Bad form, bad for discipline, and a nuisance in the
Mess. What's your Regiment? Special Reserve, you say? Humph! Sounds like
Secondhand Bicycle Trade to me!"

Now the pilot decides to change the straight gliding descent to a spiral
one, and, obedient to the Rudder, the Aeroplane turns to the left. But
the Momentum (two tons at 100 miles per hour is no small affair) heavily
resents this change of direction, and tries its level best to prevent
it and to pull the machine sideways and outwards from its spiral
course--that is, to make it "side-skid" outwards. But the Pilot deflects
the Ailerons and "banks" up the planes to the correct angle, and,
the Aeroplane skidding sideways and outwards, the lower surfaces of
the planes press up against the air until the pressure