BOX-KITES.
=Box-kites= were a new invention a very few years ago. People said,
“No use trying to put a drygoods box up in the air,” and yet something
very similar in shape has been successfully used for a number of
practical purposes. The box-kites usually require more breeze than
the plain surface kites, but are stronger pullers, which means also
heavier lifters than their lighter breeze cousins. Before entering the
discussion of box-kites, it will be well to understand some terms that
are used quite generally by all kite enthusiasts. Fig. 59 is a plain
two-celled box-kite; _a_, is the length of the kite. The framework
consists of four sticks, one at each corner, and four braces, two near
each end of the kite, placed diagonally across the inside of the kite
from one corner stick to the other. The covering consists of two bands
passing on the outside of the four corner sticks, one band at each end.
[Illustration: FIG. 59.
FIGS. 60, 61.
FIGS. 62, 63.]
The band and space enclosed is called a cell of the kite. So this kite
has two cells. The length of the cell is the same as the width of the
kite and is represented by _b_; the depth of the cell is the same as
the height of the kite in its present position, and is shown by letter
_e_; the breadth of the cell by letter _d_; and the distance between
cells, _c_, is called the vent. Nearly all box-kites require the vent,
and the vent is usually wider than the breadth of the cell. Usually the
two cells, the fore and aft, are the same size, but not necessarily so.
No one would be seen flying a box-kite with any kind of tail unless
that had a purpose in carrying out the design. The square box-kite,
Fig. 60, is square in cross-section, is very serviceable for flying,
and is convenient for carrying. It is usually made to fold up, and the
bridle is attached to one corner piece of the frame. This kite flies
diagonally in the air. It is quite easy to attach the bridle to two
corner sticks of the frame, when it flies horizontally, Fig. 61. Lining
cambric is good for covering and some bright color should be used;
but some prefer a good wrapping paper. Chinese tissue may be used if
the kite is not too large. The corner sticks stand diagonally in the
corners of the kite so that the notches of the braces can fit over
them, see Fig. 62. The drawing represents the end of the kite, with
the corner sticks stretched apart. Fig. 63 represents a part of one
of the braces. String and glue are used back of the notch to prevent
splitting when the strain is put on them up in the air. The braces are
made just a little long so that they bow a little when in place, and
this stretches the cover tight.
[Illustration: FIGS. 64, 65, 66.]
A word about getting the cover on the corner sticks may be in order.
The distance around the kite is determined, and a band is made the
right width and the right length to reach around when the braces are
sprung to place. Stretch the band out like a rubber band, Fig. 64, and
put in two corner sticks at _a_ and _b_ that have previously been glued
on one edge, and allowed to partially dry until it is what is called
tacky. Now the band at the other end should also be glued in place when
the progress will show as in Fig. 65. Remember the glue is only on the
outer edge of the sticks. Now find and mark the exact center between
the sticks glued in place and fold to these two lines, and glue in the
other two sticks in a similar manner. The progress made will be as
shown in Fig. 66. When the glue is thoroly dry, the kite is ready for
the braces and for flying. The braces might be tied together where they
cross each other. A good size for the corner sticks is 3/16” × ½” × 36”
with bands 10” wide and 64” long, plus 1” additional for the hem. This
will give 16” for each side. Enough will be needed additional in width
so as to allow a ½” hem for each side. Each band then will require a
strip of cloth or paper 11” wide and 65” long. With paper bands the ½”
should be folded over and a string should be glued inside to strengthen
the edge. The braces should be ⅛” × ½” × 21⅞” from the bottom of one
notch to the bottom of the other, see Fig. 62.
=Rectangular Kite.= The next is the rectangular kite, as shown in
Fig. 67. This is a splendid kite of its kind and should have specific
measurements. The two center pieces called the spines are ⅝” × ⅝” the
corner and cross-pieces ⅜” × ⅜”. The bands for cells are 21” wide by
18”, with 1” additional for the seam. The edges should be hemmed as
in previous kite. The framework should be all thoroly wired in every
direction as shown by drawing, Fig. 68. Little wire turnbuckles such as
are sold by firms carrying model aeroplane supplies might be used, and
the stretch of the wires could be taken up from time to time. A well
made kite will last a long time if it has good care. This particular
construction is for large kites and they are not often made to fold,
altho it is possible to make them so. Out of the box-kite has grown the
aeroplane. Some good sizes for kites are:
Six-foot kite:--6’ long, 6’ wide, 3’
deep, 1’9” width of cell, ⅝” × ⅝”
corner-pieces, 2’6” between cells, ⅝” × ⅝” spines.
Nine-foot kite:--9’ long, 9’ wide, 4’
deep, 2’6” width of cell, ¾” × ¾”
corner-pieces, 4’ between cells, 1” × 1” spines.
Twelve-foot kite:--12’ long, 12’ wide, 6’
deep, 3’6” width of cell, ⅞” × ⅞”
corner pieces, 5’ between cells, 1¼” × 1¼” spines.
[Illustration: FIG. 68.
FIG. 67.]
The two kites just described may be modified in a number of ways as
follows:--Two square kites side by side will give Fig. 69, and three
side by side Fig. 70; these might be increased in both directions until
a kite like Fig. 71 might be evolved. But there is no great gain and
much hindrance in some of these complications. If there is insufficient
room between upper and lower surface, not all of the surface is exposed
and there is skin friction, again if there is not space enough between
the fore and back cells, the front cuts off the air pressure to some
extent on the back cells. So Fig. 72 is not high enough, while Fig.
73 has the fore and back cells too close together. Fig. 74 is very
unstable in the air.
[Illustration: FIGS. 69, 70, 71, 72, 73, 74.]
[Illustration: FIGS. 75, 76, 77, 78, 79.]
The triangular cross-section has the advantage of a bracing framework
and is easy in combination. The bridle is attached to one of the long
sticks and the kite rides on a keel, Fig. 75. Three braces about
the middle of each cell keep the corner sticks out to place. These
can be put in at the field, thus allowing the kite to be rolled for
transportation. The triangular kite is sometimes lengthened so as to
use three cells, Fig. 76, and again two kites are placed side by side,
Fig. 77, and this may be increased by placing another below both, as in
Fig. 78. In the last combination we have a large kite to the outside
and a smaller one to the inside which can be lengthened so as to give
three cells in length, Fig. 79, and many other combinations can be made.
[Illustration: FIG. 80.]
[Illustration: FIG. 81.]
[Illustration: FIG. 82.]
[Illustration: FIG. 83.]
=Tetrahedral Kite.= Out of the triangular has grown the celebrated Bell
tetrahedral kites, which can be increased in size beyond that of any
other kite. No attempt will be made to give an exhaustive description
or full construction of these wonderful kites as Dr. Bell has written
a number of good articles on the subject for the _Scientific American_
and other magazines. There have been some wonderful kites made on this
principle of construction. In simple kites of this construction we have
a large tetrahedral frame composed of six sticks, Fig. 80. Owing to the
bracing effect, remarkably small material can be used. For a kite four
feet to an edge, 3/16” sticks were ample. All of the drawings given
here represent the kite resting on its keel, tho a kite left in that
position would topple over unless supported in some way. Now we will
divide this large tetrahedral horizontally by four sticks, Fig. 81,
and in Fig. 82 strings are run from the ends of the four horizontal
sticks to the middle of the keel, also to the middle of the upper ridge
stick. Some use sticks in place of the strings, but if the kite is not
too large the strings are as good and in small kites better. Fig. 83
shows a four-celled tetrahedral with the coverings on. Fig. 84 shows
a further division in which each cell of Fig. 83 is again divided
into four cells, making a 16-celled kite. The kite rides in the air
tipped as shown in Fig. 85. Look up some of the articles given in the
“Bibliography of Kites” for further discussions of this type.
[Illustration: FIG. 84.]
[Illustration: FIG. 85.]
[Illustration: FIG. 86.]
The hexagonal kite is also an outgrowth of the triangular. Looking at
the end of a hexagonal kite, three brace sticks will be seen, Fig. 86,
which can be made removable, thus allowing the kite and its covering
to be rolled. The kite will be more stable in the air if one side is
down, so the bridle will be attached to two of the long sticks, and if
it proves unmanageable, at four points.
[Illustration: FIGS. 87, 88.]
The circular cross-sectioned or barrel kite is more of a curiosity.
It has two cells, and the frame is made up of four circles, either of
split bamboo, reed, or thin tough wood. The circle should be shaped
before further construction is attempted. Most of the strain will come
on the circles so the ribs, connecting the four circles, may be quite
light and slender. There will be less danger of twisting out of shape
if more than two ribs are used. The ribs should be lashed to the rings
with thread or twisted paper. No braces are necessary in the small
ones; a long stick slanting thru the entire kite may be used in the
larger ones, see Fig. 87, with covering.
A pentagonal frame could be constructed with three braces, Fig. 88, and
should be flown in the position shown.