Kite
The Chinese are credited with inventing the first kites, perhaps as early as 1000 b.c. No one knows what inspired their creation, but they were used for pleasure and had military purposes as well, such as measuring the distance to enemy forts in order to tunnel under them.
The use of kites eventually spread from China to the Pacific. In Japan, Korea, Myanmar (until recently known as Burma), Indonesia, Melanesia, and Polynesia they attained religious and ceremonial significance. There are stories from these cultures about giant kites that could carry a person. In Japan people used kites to carry tiles and bricks to workmen constructing towers.
Kites eventually became known around the world, but it took a long time before any scientific use was made of them. In 1749 Alexander Wilson measured temperature variations at different altitudes by raising thermometers on six kites flying as high as 3,000 feet (915 m). Probably the most famous kite experiment of all involved Benjamin Franklin. In 1752 he used a kite in a thunderstorm to prove that lightning was electricity. At the top of his kite he attached a wire to attract the lightning. Near his hand he tied a silk ribbon and key to the twine. The electricity came down the wet string and out the key, as he noted when he put his hand near it.
Fifty years later, George Cayley used kites to explore the possibility of heavier-than-air flight. His first model glider used a kite as a wing unit and might have resulted in an earlier airplane if he had been able to find an adequate power source. Cayley's later gliders used kites for both wings and tail sections. One of these became the first passenger glider when it carried a servant of his across a valley in 1853.
Kites also helped save lives at sea. An Irish priest, E.J. Cordner, built a series of kites to help buoy a small boat leaving a stranded ship. In France, C. Jobart devised a lifesaving kite to fly a line from a crippled ship to the shore.
Kites continued to provide meteorological information. A British man in 1833 succeeded in lifting anemometers on kites to measure wind speeds at various altitudes. Americans established the Franklin Kite Club for further experiments, and W.R. Birt used them to study weather in 1847.
Lawrence Hargrave introduced the box kite to the world in the 1890s. This kite, the product of his search for powered flight, was extremely stable and had great lifting power. For the next thirty years it was used for meteorology. Its stability also made it a model for several early power-driven airplanes in the first decade of the twentieth century.
B.F.S. Baden-Powell was an important pioneer in man-lifting kites. He built a traditional, four-sided kite that was 36 feet (11 m) high and capable of lifting men 10 feet (3 m) off the ground. He built smaller kites that flew together, eventually carrying men as much as 100 feet (30 m) above the ground. It was with one of these kites that Guglielmo Marconi made his first successful transatlantic wireless reception tests from England to Newfoundland.
American Charles Lamson was the first to fly successfully inside a kite. Before this, pilots had been suspended below the kite. In 1897, using a structure that resembled future airplanes, Lamson built two pairs of biplane surfaces made of canvas stretched over wood. The pilot could move the back portion, thus adjusting the angle of incidence, and he could shift his weight left or right for further control. The device worked, and for half an hour at a height of 30 feet (9 m).
Meanwhile, Otto Lilienthal was exploring aerodynamics through kites. He flew gliders and eventually became the first person to achieve sustained controlled flight, often soaring for 750 feet (229 m). The Wright brothers used biplane kites to develop their heavier-than-air machine. In 1900 they flew this kite to confirm their theories of control through wing warping.
Samuel Cody established a remarkable system of man-lifting kites. He started with the box design, added several lifter kites to one flying cable and set up conical stops on the cable. Finally, he added a passenger-carrying kite attached to a trolley with wheels that ran along the cable. He hoped this arrangement could be used by observers during wartime. In 1905 he was able to send a man up 2,600 feet (793 m). Soon, however, airplanes overtook any advantages these kites might have had.
Alexander Graham Bell was also an avid kite experimenter. He created huge, multi-celled kites that looked like beehives. His Cygnet, made up of 3,393 cells and equipped with floats, carried a man for 7 minutes. He tried to add an engine for powered flight, but none were available with sufficient thrust.
As airplanes became a reality, kites were forgotten until the 1950s. But Francis Rogallo, an American, invented the flexible kite, which resulted in the famous delta wing kite used today in hang gliding. In the 1960s Domina Jolbert created a wing-shaped device made entirely of fabric that keeps its shape as the wind enters openings on its leading edge. This is now called the parafoil, the lightest, most efficient, and economical non-mechanized lifting surface yet devised.
This is the complete article, containing 863 words
(approx. 3 pages at 300 words per page).
