greater speed with no more Drift than before. Then we get
our greatest Speed, just maintaining horizontal flight.''

``Yes; though I'm out of the horizontal and thrusting
downwards,'' grumbled the Propeller, ``and that's not
efficient, though I suppose it's the best we can do until that
Inventor fellow finds his Mechanics.''

``Thank you so much,'' said Efficiency. ``I think I have
now at any rate an idea of the Elementary Principles of
Flight, and I don't know that I care to delve much deeper,
for sums always give me a headache; but isn't there something
about Stability and Control? Don't you think I ought
to have a glimmering of them too?''

``Well, I should smile,'' said a spruce Spar, who had come
all the way from America. ``And that, as the Lecturer
says, `will be the subject of our next lecture,' so be here
again to-morrow, and you will be glad to hear that it will be
distinctly more lively than the subject we have covered
to-day.''



PART II

THE PRINCIPLES, HAVING SETTLED THEIR DIFFERENCES,
FINISH THE JOB

Another day had passed, and the Flight Folk had again