top frame, twenty-one ribs placed one foot apart will be
required. On the lower frame, because of the opening
left for the operator's body, you will need only twenty.

Joining the Two Frames.

The two frames must now be joined together. For this
you will need twenty-four aluminum or iron sockets
which may be purchased at a foundry or hardware shop.
These sockets, as the name implies, provide a receptacle
in which the end of a stanchion is firmly held, and have
flanges with holes for eye-bolts which hold them firmly
to the frame pieces, and also serve to hold the guy wires.
In addition to these eye-bolt holes there are two others
through which screws are fastened into the frame pieces.
On the front frame piece of the bottom plane place six
sockets, beginning at the end of the frame, and locating
them exactly opposite the struts. Screw the sockets into
position with wood screws, and then put the eye-bolts in
place. Repeat the operation on the rear frame. Next
put the sockets for the upper plane frame in place.

You are now ready to bring the two planes together.
Begin by inserting the stanchions in the sockets in the
lower plane. The ends may need a little rubbing with
sandpaper to get them into the sockets, but care must
be taken to have them fit snugly. When all the stanchions
are in place on the lower plane, lift the upper
plane into position, and fit the sockets over the upper
ends of the stanchions.