Two years before the
publication of Penaud's patent Thomas Moy
experimented at the Crystal Palace with a twin-propelled
aeroplane, steam driven, which seems to have failed mainly
because the internal combustion engine had not yet come to
give sufficient power for weight.
Moy anchored his machine
to a pole running on a prepared circular track; his engine
weighed 80 lbs. and, developing only three horse-power, gave
him a speed of 12 miles an hour. He himself estimated that
the machine would not rise until he could get a speed of 35
miles an hour, and his estimate was correct.
Two six-bladed propellers
were placed side by side between the two main planes of the
machine, which was supported on a triangular wheeled
undercarriage and steered by fairly conventional tail
Moy realised that he could
not get sufficient power to achieve flight, but he went on
experimenting in various directions, and left much data
concerning his experiments which has not yet been deemed
worthy of publication, but which still contains a mass of
information that is of practical utility, embodying as it
does a vast amount of painstaking work.