chers,
which have their ends notched and bound to prevent splitting.

[Illustration: FIG. 116.--Plan of diamond box kite, showing arrangement
of stretchers.]

Fig. 117 is a perspective diagram of a kite. The sail of each box measures
from top to bottom one-sixth the total circumference of the box, or, to
express the matter differently, each face of the box is half as long again
as its depth. The distance separating the boxes is equal to the depth of a
box.

The sides of a box make angles of 60 degrees and 120 degrees with one
another, the depth of the space enclosed from front to back being the same
as the length of a side. With these angles the effective area of the sails
is about six-sevenths of the total area. Therefore a kite of the dimensions
given in Fig. 117 will have an effective area of some thirty square feet.

[Illustration: FIG. 117.--Diamond box kite in perspective. Ties are
indicated by fine dotted lines.]

The long stretchers pass through holes in the fabric close to the sticks,
and are connected with the sticks by stout twine. Between stretcher and
stick is interposed a wedge-shaped piece of wood (A in Fig. 115), which
prevents the stick being drawn out of line. This method of attachment
enables the boxes to be kept tight should the fabric stretch at all--as
generally happens after some use; also it does away with the necessity for
calculating the length of the stretchers exactly.

The stretchers are tied together at the crossing points to give support to
the longer of the pair.

The dotted lines AB, AC, AD, EM, and EN in Fig. 117 indicate ties made with
wire or doubled and hemmed strips of the fabric used for the wings. AB,
running from the top of the front stick to the bottom of the back stick,
should be of such a length that, when the kite is stood on a level surface,
the front and back sticks make right angles with that surface, being two
sides of a rectangle whereof the other two sides are imaginary lines
joining the tops and bottoms of the sticks. This tie prevents the back of
the kite drooping under pressure of the wind, and increases the angle of
flight. The other four ties prevent the back sails turning over at the
edges and spilling the wind, and also keep them flatter. This method of
support should be applied to the type of kite described in the first
section of this chapter.

String Attachment.--A box kite will fly very well if the string is
attached to the top box only. The tail box