at the wing connection
with the body is forward of the line A, which
represents the point at which the body will balance
itself, and this line passes through the wings
so that there is an equal amount of supporting
surface fore and aft of the line.

Again, the wing attachment is at the upper side
of the body, and the vertical dimension of the
body, or its thickness, is equal to four-fifths of the
length of he wing.

The wing socket permits a motion similar to a
universal joint, Fig. 55 showing how the inner
end of the wing has a downward bend where it
joins the back, as at B.

THE MONOPLANE FORM.--For the purpose of
making comparisons the illustrations of the monoplane
show a machine of 300 square feet of surface,
which necessitates a wing spread of forty
feet from tip to tip, so that the general dimensions
of each should be 18 1/2 feet by 8 1/2 feet at its
widest point.

First draw a square forty feet each way, as in
Fig. 58, and through this make a horizontal line
1, and four intermediate vertical lines are then
drawn, as 2, 3, 4, 5, thus providing five divisions,
each eight feet wide. In the first division the
planes A, B, are placed, and the tail, or elevator
C, is one-half the width of the last division.

_Fig. 58. Plan of Monoplane._

The frame is 3 1/2 feet wide at its forward end,
and tapers down to a point at its rear end, where
the vertical control plane D is hinged, and the
cross struts E, E, are placed at the division lines
3, 4, 5.

The angles of the planes, with relation to the
frame, are usually greater than in the biplane,
for the reason that the long tail plane requires
a greater angle to be given to the planes when
arising; or, instead of this, the planes A, B, are
mounted high enough to permit of sufficient angle
for initiating flight without injuring the tail D.

Some monoplanes are built so they have a support
on wheels placed fore and aft. In others
the tail is supported by curved skids, as shown
at A, Fig. 59, in which case the forward
supporting wheels are located directly beneath the plan