At some point in life, almost everyone has run across a park or a field holding a kite by its string as it flew high in the sky. This fun memory can cause people to view kites as mere recreational toys for children. But kites are, and have always been, so much more than the brightly colored contraptions commonly seen today. They have a long and interesting history, and their creation has led to findings that have played an important part in the advancement of modern technology. A thorough understanding of kites — from how they work to the roles they have played in the past — can deepen one's appreciation of their purpose and ultimately enrich the enjoyment of flying them.
Ancient Origins
Many believe that the first kites came from China more than 2,000 years ago. While this is a popular belief, it is not shared by everyone. Some suggest that kites may have also originated in Indonesia or Malaysia. Although it is unclear exactly when kites were used in these areas, records indicate that their purpose was for fishing — accomplished by attaching bait and a net to the kite's tail to catch and hold fish. The earliest documentation supports China as the place that first created kites. Somewhere between 468 and 376 B.C., a philosopher named Mo Di (or Mo-tse) lived on Mount Lu, where he created a wooden eagle that he was able to make fly for a day. His design was later improved by his student Gongshu Ban, who created a bamboo and silk magpie that flew continuously for three days.
Military Uses Through History
Early kites were large and often used for military purposes. Some were used for spreading propaganda, while others were able to carry individuals aloft to observe enemy movements or act as snipers. Some kites became famous, even ones that failed to achieve the desired results. For example, in Nanjing, Emperor Wu Di once attempted unsuccessfully to send an SOS via kite. Another notable example came when Gen. Han Hsin flew a kite over his enemy's castle and later used the length of the string as a measurement for digging a tunnel. The Chinese call kites "fengzheng," which translates to "wind harp." This name comes from a time when kites were fitted with bamboo pieces that would vibrate and make a sound when stirred by a breeze.
Spreading Across the World
Kites eventually made their way from Asia to other parts of the world, particularly Europe, courtesy of Marco Polo. From Europe, the kite would eventually arrive in America. They were used not only for military purposes but for scientific ones as well. In 1749, Alexander Wilson, a Scottish astronomer and meteorologist, made his first attempt at using kites to measure air temperature. Another notable scientific use came in the mid-1700s when Benjamin Franklin famously flew a kite into a thundercloud.
A Stepping Stone to Manned Flight
Early kites were sometimes used to carry men for military purposes and, as such, could be considered an early form of air travel. This concept was more seriously explored in 1894 when Lawrence Hargrave connected four cellular kites and, with the addition of a sling seat, was able to fly roughly 16 feet. As a result, his work with kites became a successful step toward the creation of manned aircraft. During World War II, kites were used for anti-aircraft target practice.
The Science of Flight
A kite requires wind, which creates pressure that lifts or pushes the kite. Without wind, there is no lift, and the kite would fall. There must be enough lift to overcome the downward pull of gravity and the wind resistance on the tail and surface of the kite, known as drag. To create lift, the air pressure below the kite must be higher than the air pressure above. This can be achieved by strong winds or when the kite itself moves at a sufficiently high speed — for example, when biking or running while pulling the kite along.