ill; have her
name in all the papers, with her portrait; see the walls covered with her
posters. What a revenge for her! That was enough, for the moment. She did
not want to appear surprised before Jimmy. The right thing was to take it
as something very natural, like a lady who is used to the best.

Jimmy, meanwhile, was explaining his trick:

"We shan't fly at once," he said. "We shall practise on the stand to learn
how the handles work. Oh, you'll have to think of everything during the
few seconds that the flight lasts! The machine isn't perfect, it's a first
attempt, it can only be ridden by a professional and a very clever one.
Look here," he continued, "it's the principle of the back-wheel; you'll
have to keep your side-balance and front and back, but you'll do it, I'm
sure. _I've_ done it."

"What you can do, a man," Lily interrupted, "I can do too. One can do
anything on the bike!"

The machine which Jimmy explained to Lily in detail was a bike just like
another, with a few differences in its general construction, bearing upon
the services which it was expected to perform. The saddle, for instance,
was made to slide backward and forward, so that the center of equilibrium
could be shifted with a push of the rider's back. The stability of the
apparatus did not depend upon that alone. The ascensional rudder or
screw-propeller, which was able to impart a speed of thirty miles an hour
to the machine, was in the extension of the horizontal bar of the frame.
It was fitted to a long piece of bent steel, pinned below the saddle,
which, running beside the frame, ended by forming a pedal, so that, with a
pressure of the foot, the rider could move it downward, at will, within an
arc of some ten degrees. This propeller, which was small in dimensions,
but endowed with enormous speed, was, in its normal position,
perpendicular to the frame. The pressure of the foot raised it to its
highest point. In this position, the propeller turned at full speed and
therefore tended to descend and, consequently, to point the front of the
aerobike upward. When brought still lower, its ascensional force increased
and the front of the aerobike pitched downward. These two extremes would
obviously serve only in sudden movements. In reality, the rider's skill
would consist in moving the propeller only very slightly, in order to
maintain a horizontal flight. As for the machine itself, Jimmy had
rejected the cumbersome system of cells, which he c