The cutting and arrangement of the stretchers and the holes for the same require some thought. Each stretcher lies behind its wing, passes in front of the rod nearest to it, and behind that at the corner diagonally opposite. (See Fig. 119.) The slits through which it is thrust should be strengthened with patches to prevent ripping of the material.
Two persons should hold a box out as squarely as possible while a stretcher is measured. Cut a nick 3/8 inch deep in one end of the stretcher, and pass the end through the fabric slits to the ring not on the wing. Pull the wing out, holding it by its ring, and cut the stretcher off 1 inch from the nearest point of the ring. The extra length will allow for the second nick and the tensioning of the material. Now measure off the second stretcher by the first, nick it, and place it in position. If the tension seems excessive, shorten the rods slightly, but do not forget that the fabric will stretch somewhat in use.
[Illustration: FIG. 121.—Box kite with front and back wings.]
Make the stretchers for the second box, and place them in position. The wings ought to be pretty taut if the adjustments are correct, but should they show a tendency to looseness, a third pair of stretchers of light bamboo may be inserted between the other two, being held up to the rods by loops of tape. In order to be able to take up any slackness, the wing end of each stretcher may be allowed to project a couple of inches, and be attached by string to the near ring, as described on p. 271. The bridle to which the flying string is attached is made up of four parts, two long, two short, paired exactly as regards length. These are attached to eyes screwed into the front rods three inches below the tops of the boxes. Adjustment is made very easy if a small slider is used at the kite end of each part. These sliders should be of bone or some tough wood, and measure 1 inch by 3/8 inch. The forward ends of the bridle are attached to a brass ring from which runs the flying string.
It is advisable to bind the stretchers with strong thread just behind the notches to prevent splitting, and to loosen the stretchers when the kite is not in use, to allow the fabric to retain as much as possible of its elasticity.
The area of the kite affected by wind is about 14 square feet; the total weight, 1-1/2 lb. The cost of material is about 2s.
The experience gained from making the kite described may be used in the construction of a larger kite, six or more feet high, with boxes 30 by 22 by 22 inches, and wings 24 inches wide at the broadest point. If a big lift is required, or it is desired to have a kite usable in very light breezes, a second pair of wings slightly narrower than those at the back may be attached permanently to the front of the boxes, or be fitted with hooks and eyes for use on occasion only. (Fig. 121.) In the second case two sets of stretchers will be needed.
[Illustration: FIG. 122.—Simple string winder for kite.]
Note.—If all free edges of boxes and wings are cut on the curve, they will be less likely to turn over and flap in the wind; but as the curvature gives extra trouble in cutting out and stitching, the illustrations have been drawn to represent a straight-edged kite.
Kite Winders.—The plain stick which small children flying small kites on short strings find sufficient for winding their twine on is far too primitive a contrivance for dealing with some hundreds of yards, may be, of string. In such circumstances one needs a quick-winding apparatus. A very fairly effective form of winder, suitable for small pulls, is illustrated in Fig. 122.