1911 Encyclopædia Britannica/Kite-flying

From Wikisource
Jump to navigation Jump to search

KITE-FLYING, the art of sending up into the air, by means of the wind, light frames of varying shapes covered with paper or cloth (called kites, after the bird — in German Drache, dragon), which are attached to long cords or wires held in the hand or wound on a drum. When made in the common diamond form, or triangular with a semicircular head, kites usually have a pendulous tail appended for balancing purposes. The tradition is that kites were invented by Archytas of Tarentum four centuries before the Christian era, but they have been in use among Asiatic peoples and savage tribes like the Maoris of New Zealand from time immemorial. Kite-flying has always been a national pastime of the Koreans, Chinese, Japanese, Tonkinese, Annamese, Malays and East Indians. It is less popular among the peoples of Europe. The origin of the sport, although obscure, is usually ascribed to religion. With the Maoris it still retains a distinctly religious character, and the ascent of the kite is accompanied by a chant called the kite-song. The Koreans attribute its origin to a general, who, hundreds of years ago, inspirited his troops by sending up a kite with a lantern attached, which was mistaken by his army for a new star and a token of divine succour. Another Korean general is said to have been the first to put the kite to mechanical uses by employing one to span a stream with a cord, which was then fastened to a cable and formed the nucleus of a bridge. In Korea, Japan and China, and indeed throughout Eastern Asia, even the tradespeople may be seen indulging in kite-flying while waiting for customers. Chinese and Japanese kites are of many shapes, such as birds, dragons, beasts and fishes. They vary in size, but are often as much as 7 ft. in height or breadth, and are constructed of bamboo strips covered with rice paper or very thin silk. In China the ninth day of the ninth month is “Kites' Day,” when men and boys of all classes betake themselves to neighbouring eminences and fly their kites. Kite-fighting is a feature of the pastime in Eastern Asia. The cord near the kite is usually stiffened with a mixture of glue and crushed glass or porcelain. The kite-flyer manœuvres to get his kite to windward of that of his adversary, then allows his cord to drift against his enemy's, and by a sudden jerk to cut it through and bring its kite to grief. The Malays possess a large variety of kites, mostly without tails. The Sultan of Johor sent to the Columbian Exposition at Chicago in 1893 a collection of fifteen different kinds. Asiatic musical kites bear one or more perforated reeds or bamboos which emit a plaintive sound that can be heard for great distances. The ignorant, believing that these kites frighten away evil spirits, often keep them flying all night over their houses.

There are various metaphorical uses of the term “kite-flying,” such as in commercial slang, when “flying a kite” means raising money on credit (cf. “raising the wind”), or in political slang for seeing “how the wind blows.” And “flying-kites,” in nautical language, are the topmost sails.

Kite-flying for scientific purposes began in the middle of the 18th century. In 1752 Benjamin Franklin made his memorable kite experiment, by which he attracted electricity from the air and demonstrated the electrical nature of lightning. A more systematic use of kites for scientific purposes may, however, be said to date from the experiments made in the last quarter of the 19th century. (E. B.)

Meteorological Use. — Many European and American meteorological services employ kites regularly, and obtain information not only of the temperature, but also of the humidity and velocity of the air above. The kites used are mostly modifications of the so-called box-kites, invented by L. Hargrave. Roughly these kites may be said to resemble an ordinary box with the two ends removed, and also the middle part of each of the four sides. The original Hargrave kite, the form generally used, has a rectangular section; in Russia a semicircular section with the curved part facing the wind is most in favour; in England the diamond-shaped section is preferred for meteorological purposes owing to its simplicity of construction. Stability depends on a multitude of small details of construction, and long practice and experience are required to make a really good kite. The sizes most in use have from 30 to 80 sq. ft. of sail area. There is no difficulty about raising a kite to a vertical height of one or even two miles on suitable days, but heights exceeding three miles are seldom reached. On the 29th of November 1905 at Lindenberg, the Prussian Aeronautical Observatory, the upper one of a train of six kites attained an altitude of just four miles. The total lifting surface of these six kites was nearly 300 sq. ft., and the length of wire a little over nine miles. The kites are invariably flown on a steel wire line, for the hindrance to obtaining great heights is not due so much to the weight of the line as to the wind pressure upon it, and thus it becomes of great importance to use a material that possesses the greatest possible strength, combined with the smallest possible size. Steel piano wire meets this requirement, for a wire of 1/32 in. diameter will weigh about 16 lb to the mile, and stand a strain of some 250-280 lb before it breaks. Some stations prefer to use one long piece of wire of the same gauge throughout without a join, others prefer to start with a thin wire and join on thicker and thicker wire as more kites are added. The process of kite-flying is as follows. The first kite is started either with the self-recording instruments secured in it, or hanging from the wire a short distance below it. Wire is then paid out, whether quickly or slowly depends on the strength of the wind, but the usual rate is from two to three miles per hour. The quantity that one kite will take depends on the kite and on the wind, but roughly speaking it may be said that each 10 sq. ft. of lifting surface on the kite should carry 1000 ft. of 1/32 in. wire without difficulty. When as much wire as can be carried comfortably has run out another kite is attached to the line, and the paying out is continued; after a time a third is added, and so on. Each kite increases the strain upon the wire, and moreover adds to the height and makes it more uncertain what kind of wind the upper kites will encounter; it also adds to the time that is necessary to haul in the kites. In each way the risk of their breaking away is increased, for the wind is very uncertain and is liable to alter in strength. Since to attain an exceptional height the wire must be strained nearly to its breaking point, and under such conditions a small increase in the strength of the wind will break the wire, it follows that great heights can only be attained by those who are willing to risk the trouble and expense of frequently having their wire and train of kites break away. The weather is the essential factor in kite-flying. In the S.E. of England in winter it is possible on about two days out of three, and in summer on about one day out of three. The usual cause of failure is want of wind, but there are a few days when the wind is too strong. (For meteorological results, &c., see Meteorology.) (W. H. Di.)

Military Use. — A kite forms so extremely simple a method of lifting anything to a height in the air that it has naturally been suggested as being suitable for various military purposes, such as signalling to a long distance, carrying up flags, or lamps, or semaphores. Kites have been used both in the army and in the navy for floating torpedoes on hostile positions. As much as two miles of line have been paid out. For purposes of photography a small kite carrying a camera to a considerable height may be caused to float over a fort or other place of which a bird's-eye view is required, the shutter being operated by electric wire, or slow match, or clockwork. Many successful photographs have been thus obtained in England and America.

The problem of lifting a man by means of kites instead of by a captive balloon is a still more important one. The chief military advantages to be gained are: (1) less transport is required; (2) they can be used in a strong wind; (3) they are not so liable to damage, either from the enemy's fire or from trees, &c., and are easier to mend; (4) they can be brought into use more quickly; (5) they are very much cheaper, both in construction and in maintenance, not requiring any costly gas.

Captain B. F. S. Baden-Powell, of the Scots Guards, in June 1894 constructed, at Pirbright Camp, a huge kite 36 ft. high, with which he successfully lifted a man on different occasions. He afterwards improved the contrivance, using five or six smaller kites attached together in preference to one large one. With this arrangement he frequently ascended as high as 100 ft. The kites were hexagonal, being 12 ft. high and 12 ft. across. The apparatus, which could be packed in a few minutes into a simple roll, weighed in all about 1 cwt. This appliance was proved to be capable of raising a man even during a dead calm, the retaining line being fixed to a wagon and towed along. Lieut. H.D. Wise made some trials in America in 1897 with some large kites of the Hargrave pattern (Hargrave having previously himself ascended in Australia), and succeeded in lifting a man 40 ft. above the ground. In the Russian army a military kite apparatus has also been tried, and was in evidence at the manœuvres in 1898. Experiments have also been carried out by most of the European powers. (B. F. S. B.-P.)