How to Build a Glider

    A gliding machine is a motorless
aeroplane, or flying-machine, propelled
by gravity and designed to carry a pass-
enger through the air from a high point
to a lower point some distance away.
Flying in a glider is simply coasting
down hill on the air, and is the most in-
teresting and exciting sport imagin-
able.  The style of glider described in
this article is known as the "two-sur-
face" or "double-decked" aeroplane, and
is composed of two arched cloth sur-
faces placed one above the other.

    In building a glider, the wood mate-
rial used should be straight-grained
spruce, free from knots.  First prepare
from spurce planks these strips of wood.

    The frames for the two main 
surfaces should be constructed first, 
by bolting the crosspieces to the long 
beams at the places shown by the
dimensions in Fig. 1.  If 20-ft. lumber
cannot be procured, use 10-ft. lengths
and splice them, as shown in Fig. 3.  
All bolts used should be 1/8 in. in
diameter and fitted with washers on
both ends.  These frames formed by the
crosspieces should be braced by diagonal
wires as shown.  All wiring is done with
No. 16 piano wire.  

    The 41 ribs may be nailed to the
main frames on the upper side by using
fine flat-headed brads 7/8 in. long.  These
ribs are spaced 1 ft. apart and extend
1 ft. beyond the rear edges of the main
frames, as shown in Fig. 1.  After nail-
ing one end of the rib to the front long
beam, the rib is arched by springing 
down the loose end and nailing to the
rear beam.  The ribs should have a
curve as shown in Fig. 2, the amount
of curvature being the same in all the
ribs.

    The frames of the main surfaces are
now ready to be covered with cloth.
Cambric or bleached muslin should be
used for the covering, which is tacked
to the front edge, stretched tightly over
the bent ribs and fastened securely with
tacks to the rear ends of the ribs.  The
cloth should also be glued to the ribs
for safety.  In the center of the lower
plane surface there should be an open-
ing 2 ft. wide and 4 ft. long for the
body of the operator.  Place the two
main surfaces 4 ft. apart and connect
with the 12 uprights, placed in the cor-
ner of each crosspiece and beam.  The
uprights are fastened by bolting to the
crosspieces, as shown in Fig. 2.  The
whole structure is made strong and
rigid by bracing with diagonal wires,
both laterally and longitudinally.

    The vertical rudder is to keep the
machine headed into the wind, and is
not movable.  This rudder is made of
cloth stretched over a light wooden
frame, which is nailed to the rudder
sticks connecting to the main frame.
The horizontal rudder is also made of
cloth stretched over a light wooden
frame, and arranged to intersect the
vertical rudder at its center.  This rud-
der in held in position and strengthened
by diagonal wires and guy wires.  The
horizontal rudder is also immovable,
and its function is to prevent the ma-
chine from diving, and also to keep it
steady in its flight.  The rudders are
fastened to the glider by the two rud-
der sticks, and these sticks are held
rigid by diagonal wires, and also by guy
wires leading to the sides of the main
frames as shown in Fig. 1.  The two
arm sticks should be spaced about 13
in. apart and bolted to the long beams
in the corner of the opening in the
lower plane where the operator is to
take his position.

    The glider should be examined to see
that the frame is not warped or twisted.
The surfaces must be true or the ma-
chine will be hard to balance when in
flight.  To make a glide, take the glider
to the top of a hill, get in between the
arm sticks and lift the machine up un-
til the arm sticks are under the arms as
shown, run a few steps against the wind
and leap from the ground.  You will
find that the machine has a surprising
amount of lift, and if the weight of the
body is in the right place, you will go
shooting down the hillside in free flight.
The landing is made by pushing the 
weight of the body backwards.  This
will cause the glider to tip up in front,
slacken speed and settle.  The operator
can then land safely and gently on his
feet.  Of course, the beginner should
learn by taking short jumps, gradually
increasing the distance as he gains skill
and experience in balancing and land-
ing.

    The proper position of the body is
slightly ahead of the center of the 
planes, but this must be found by ex-
perience.  The machine should not be
used in winds blowing faster than 15
miles an hour.  Glides are always made
against the wind, and the balancing is
done by moving the legs.  The higher
the starting point the farther one may
fly.  Great care should be exercised in
making landings.  Otherwise the opera-
tor might suffer a sprained ankle, or
perhaps a broken limb.  The illustra-
tion shows two lines of flight from a
hilltop, the glider travels on the upper
line caused by the body of the operator
taking a position a little back of the
proper place, and on the lower line he
changes his position from front to back
while flying, which causes the dip in
the line.