rudder and tip the machine up
in front, and vice versa. He was practicing this on some natural hills
outside Berlin, and he apparently got muddled with the two motions, and,
in trying to regain speed after he had, through a lull in the wind, come
to rest in the air, let the machine get too far down in front, came down
head first and was killed.'

Then in another passage Pilcher enunciates what is the true value of
such experiments as Lilienthal--and, subsequently, he himself--made:
'The object of experimenting with soaring machines,' he says, 'is to
enable one to have practice in starting and alighting and controlling a
machine in the air. They cannot possibly float horizontally in the
air for any length of time, but to keep going must necessarily lose in
elevation. They are excellent schooling machines, and that is all they
are meant to be, until power, in the shape of an engine working a screw
propeller, or an engine working wings to drive the machine forward, is
added; then a person who is used to soaring down a hill with a simple
soaring machine will be able to fly with comparative safety. One can
best compare them to bicycles having no cranks, but on which one could
learn to balance by coming down an incline.'

It was in 1895 that Lilienthal passed from experiment with the monoplane
type of glider to the construction of a biplane glider which, according
to his own account, gave better results than his previous machines.
'Six or seven metres velocity of wind,' he says, 'sufficed to enable
the sailing surface of 18 square metres to carry me almost horizontally
against the wind from the top of my hill without any starting jump. If
the wind is stronger I allow myself to be simply lifted from the point
of the hill and to sail slowly towards the wind. The direction of the
flight has, with strong wind, a strong upwards tendency. I often reach
positions in the air which are much higher than my starting point. At
the climax of such a line of flight I sometimes come to a standstill
for some time, so that I am enabled while floating to speak with the
gentlemen who wish to photograph me, regarding the best position for the
photographing.'

Lilienthal's work did not end with simple gliding, though he did not
live to achieve machine-driven flight. Having, as he considered, gained
sufficient experience with gliders, he constructed a power-driven
machine which weighed altogether about 90 lbs., and this was thoroughly
tested. T