round, but with the aid of the Propeller Slip[[1]] and a
friendly lift from the Surface she was at length revived and
regained a more normal aspect.


[[1]] Propeller Slip: As the propeller screws through the air,
the latter to a certain extent gives back to the thrust of the
propellor blades, just as the shingle on the beach slips back
as you ascend it. Such ``give-back'' is known as ``slip,''
and anyone behind the propellor will feel the slip as a
strong draught of air.


Said the Stagger with a raffish air, ``My dear young lady,
I assure you that from the experiences of a varied career,
I have learned that perfection is impossible, and I am sure
the Designer will be quite satisfied if you become the Most
Efficient Compromise.''

``Well, that sounds so common sense,'' sighed Efficiency,
``I suppose it must be true, and if the Designer is satisfied,
that's all I really care about. Now do let's get on with the job.''

So the Chalk drew a nice long slim body to hold the
Engine and the tanks, etc., with room for the Pilot's and
Passenger's seats, and placed it exactly in the middle of the
Biplane. And he was careful to make its position such that
the Centre of Gravity was a little in advance of the Centre
of Lift, so that when the Engine was not running and there
was consequently no Thrust, the Aeroplane should be ``nose-