to describe.

15 indicates a rope or other flexible connection extending lengthwise
of the front of the machine above the lower aeroplane, passing under
pulleys or other suitable guides 16 at the front corners e and f of the
lower aeroplane, and extending thence upward and rearward to the upper
rear corners c and d, of the upper aeroplane, where they are attached,
as indicated at 17. To the central portion of the rope there is
connected a laterally-movable cradle 18, which forms a means for moving
the rope lengthwise in one direction or the other, the cradle being
movable toward either side of the machine. We have devised this cradle
as a convenient means for operating the rope 15, and the machine is
intended to be generally used with the operator lying face downward on
the lower aeroplane, with his head to the front, so that the operator's
body rests on the cradle, and the cradle can be moved laterally by the
movements of the operator's body. It will be understood, however, that
the rope 15 may be manipulated in any suitable manner.

19 indicates a second rope extending transversely of the machine along
the rear edge of the body portion of the lower aeroplane, passing under
suitable pulleys or guides 20 at the rear corners g and h of the lower
aeroplane and extending thence diagonally upward to the front corners a
and b of the upper aeroplane, where its ends are secured in any suitable
manner, as indicated at 21.

Considering the structure so far as we have now described it, and
assuming that the cradle 18 be moved to the right in Figs. 1 and 2,
as indicated by the arrows applied to the cradle in Fig. 1 and by the
dotted lines in Fig. 2, it will be seen that that portion of the rope 15
passing under the guide pulley at the corner e and secured to the corner
d will be under tension, while slack is paid out throughout the other
side or half of the rope 15. The part of the rope 15 under tension
exercises a downward pull upon the rear upper corner d of the structure
and an upward pull upon the front lower corner e, as indicated by the
arrows. This causes the corner d to move downward and the corner e to
move upward. As the corner e moves upward it carries the corner a upward
with it, since the intermediate standard 8 is substantially rigid and
maintains an equal distance between the corners a and e at all times.
Similarly, the standard 8, connecting the corners d and h, causes the
corner h to move downward in unison wi