Kites come in many shapes and sizes, but all have the same basic parts. Most kites need a tail for stability and proper flight--without a tail, a kite will come crashing back to Earth. Tails can also be used for decorative effect.
Tail as Necessity
Kites rely on their tails to create drag--that is, rather than just blowing over and under the kite, air is forced to move around the tail. This interaction keeps the wind in check, thus reducing its effect on the kite. One result of this is that a kite will point into the wind while its bottom points toward the ground. Small kites and flat kites won't last long in the air without tails.
On the other hand, some kite enthusiasts want their kites to roll and pitch, so a tail may not be used. Fighter or stunt kites, for instance, often are tailless.
Problems and Solutions
If a kite has trouble staying in the air, it might be because it has no tail or the tail isn't long enough to stabilize the kite. But a tail also can be the culprit by weighing too much and creating too much drag. Too much drag prevents a kite from gaining altitude. Generally, the lighter the wind, the shorter the tail should be, and vice versa. Not only does a longer tail in a challenging wind stabilize the kite, it also slows it down so it's easier to control.
Parts of a Kite
All kites have a frame covered by material and a string that will serve as a tether. This string, called the tow line or kite line, is attached to a bridle, which is another string attached to the top and bottom of the kite. The top of the kite is called the nose. Tails hang from the bottom of the kite and are made of lightweight materials such as crepe paper, streamers, plastic of the weight found in garbage bags, or long string with light ribbons tied at intervals along it.
Kites have been flown for thousands of years and are not always considered simply toys. In Asia, they are often artistic and made musical by the addition of pipes that make sounds as wind passes through them. Kites were once used as protectors to keep people safe from "evil spirits."
Kites and Science
Although now flown mostly for fun, kites also used to serve as scientific tools. In the 13th century, scientist Roger Bacon studied kites' flying behavior, deciding that air, like water, had the potential to carry airships. The Wright brothers also drew on their understanding of kites to work out how to get aircraft to fly. In 1749, Alexander Wilson used kites to measure atmospheric temperature at different altitudes. In the early 20th century, meteorologists used kites to send meteorological equipment into the sky.