to move
with an
incredible
speed,
without
the aid of
any
animal.
Finally,
it would
not be
impossible
to make
machines,
which, by
means of a
suit of
wings,
should fly
in the air
in the
manner of
birds."But
the secret
slept with
Bacon. The
six
hundred
years have
not yet
fulfilled
his words.
Two
centuries
ago, the
sawing of
timber was
done by
hand; the
carriage
wheels ran
on wooden
axles; the
land was
tilled by
wooden
ploughs.
And it was
to little
purpose,
