We returned home, after these experiments, with the conviction that sailing flight was not the exclusive prerogative of birds.
All flight is based upon producing air pressure, all flight energy consists in overcoming air pressure.
The airplane stays up because it doesn't have the time to fall.
I have discovered that a screw-shaped device such as this, if it is well made from starched linen, will rise in the air if turned quickly.
Aerodynamics is for those who cannot manufacture good engines.
