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Balloon


Balloon
From ancient times, people have dreamed up in the air, to float there like birds. It is they who are imitated in his first attempt to get off the ground. But, alas ... Numerous experiments with artificial wings gave the same result - the man could not fly, no matter how hard he tried. In the Middle Ages, when opened was the hot air's ability to raise the lightweight body, the idea to use it to lift the person. Several ingenious balloon designs have been proposed by different scientists over the XVI-XVII centuries. However, in reality, these ideas were put into practice only at the end of the XVIII century. In 1766 Cavendish discovered hydrogen - a gas which is 14 times lighter than air. In 1781, Italian physicist Cavell conducted experiments with soap bubbles filled with hydrogen - are readily entrained in height. Thus, the principle of the balloon has been designed. It remained to find material for his shell. It was not immediately apparent. All the fabrics used were previously or are too heavy, or passed through a hydrogen. The problem was resolved Paris Professor Charles, who came up to make a shell made of silk, impregnated rubber. But before Charles managed to start the construction of the balloon, a balloon launch brothers Etienne and Joseph Montgolfier, sons of a paper manufacturer from Anone.

Montgolfier brothers had the scientific knowledge that Charles had, but they had a lot of enthusiasm and perseverance. However, their initial attempts were unsuccessful. First they tried to fill a paper ball in pairs, then smoke. Later, they came across an essay Priestley about the different sorts of air, in which there were many important observations about the different properties of gases.

Armed with this information, we try to fill the Montgolfier hydrogen balloon, but they failed to produce a skin that could keep the light gas. In addition, hydrogen was worth while quite expensive. Leaving his brothers returned to their experiences with the air. They believed that a mixture of chopped straw and wool must be formed during combustion of a special electric couples having a great lift. Despite the absurdity of this assumption, experiments with hot air yielded a good result. The first balloon, the volume of slightly more than one cubic meter, after filling with hot air rose to a height of 300 meters. Inspired by this success, the brothers started the production of a large balloon of about 600 cubic meters and a diameter of 11 meters. His silk shell inside pasted paper. Above the bottom of his hole was reinforced lattice of vines, on which was placed a brazier.

And June 5, 1783 held a test flight of the balloon with a large gathering of people. On the hearth fire was divorced, and raised the wet hot air balloon to an altitude of 2000 meters. Glee audience knew no bounds! This experiment aroused great interest in Europe. Paris Academy had delivered a report about it. It, however, has not been reported than Montgolfier balloon filled her - it was a secret invention.

When Charles learned about successful balloon flight (the so-called steel balls filled with hot air), he took up with renewed vigor for the construction of his balloon. Skilled mechanics Robert brothers helped him. The sheath diameter 3 to 6 m were made of rubberized silk. Below it ended in a hose with a valve, through which it had filled with hydrogen. At the time this was not an easy task. The first difficulty consisted in the production of hydrogen. For this purpose, Charles came up with the following instrument: the barrel put iron filings and water is poured on them. On the top of the barrel drilled two holes. One stuck leather sleeve connected to the balloon and another was poured into sulfuric acid. At the same time, however, it was found that the reaction proceeds very rapidly, and the water is heated in a vapor carried along with hydrogen into the balloon. The water was acid solution, which was beginning to erode the shell. To avoid this, Charles came up to pass the resulting hydrogen through the vessel with the cold water. Thus the gas is cooled and simultaneously purified. It went well, and on the fourth day of the installation balloon was filled.

August 27, 1783 on the Champ de Mars was launched first charliere (so-called steel balls filled with hydrogen). More than 200 thousand Parisians were present at this unprecedented sight. The ball soared rapidly and after a few minutes was already above the clouds. But when the balloon rose to a height of about 1 kilometer, its shell burst on the expanded hydrogen and fell near Paris in Gonesse crowd of peasants of the village who did not have any idea of ​​the causes of what is happening. Most of them thought that the moon fell. When the peasants saw that the monster is quite calm, they attacked him with flails and pitchforks, and in a short time terrible stabbed and tore the remnants of the world. Rushed from Paris to the place of the fall of his balloon Charles found only his miserable rags. Beautiful creation of human hands, which was spent on about 10 thousand francs lost irretrievably. However, apart from this sad ending, the whole experience was a success.

One of the spectators who were present at the launch on August 27 was Etienne Montgolfier. He accepted a challenge Charles and 19 September of the same year at Versailles before the eyes of the king and the countless crowds of the curious with his brother picked up the ball in the air with a diameter of 12, 3 meters with the world's first aeronauts. This honor was a sheep, a rooster and a duck. Ten minutes later, the ball slowly dropped to the ground. After inspecting the animals, it was found that the rooster damaged wing, and it was enough to between scientists heated debate about the possibility of living at high altitudes. It was feared that living creatures can suffocate if will rise to a height of more than a kilometer, because no one has yet studied this mysterious atmosphere. The next balloon being built King Louis XVI ordered to put two offenders who were in prison. But ambitious Pilatre de Rozier and the Marquis d'Arland persuaded the king, that the glory of the first people-balloon must not be tainted even if unsuccessful rise. This honor of the king was forced to give them. November 21, 1783 a huge hot air balloon 21 meters high with two daredevils rose from the castle of La Muette near Paris, and reached an altitude of 1000 meters, opening a new page in the history of mankind. Both aeronaut not sitting idly by, and kept the fire on the grate at the bottom of the shell. The flight lasted about 45 minutes and ended with a smooth descent in the country at a distance of 9 km from the starting point.

However, Professor Charles and the Robert brothers also did not waste time. Declaring membership, they collected 10 thousand francs for the manufacture of a new charliere to lift two people. When designing its second balloon Charles invented almost all the equipment, which is used by balloonists to this day. The shell diameter of 8 meters in three days filled with hydrogen, and December 1, 1783 Charles with one of Robert's brothers, in spite of the threatened them until the last moment of the prohibition of the king, entered the gondola suspended under the ball and Etienne Montgolfier were asked to cut the rope holding the balloon. The flight lasted 2 hours 5 minutes at an altitude of 400 meters. After landing, Charles decided to continue the flight alone. Lightweight (without Robert) balloon soared to an altitude of 3000 meters. After a half hour flight, releasing a portion of the hydrogen, Charles made a soft landing. Coming out of the gondola, he vowed "never to expose themselves to the dangers of such a trip." Curiously, his rivals came to the same decision. Etienne Montgolfier in general never in his life did not get up in the air, and his brother, Joseph decided to do so only once. (The flight took place on January 5, 1784, on a hot air balloon were, except Joseph, Pilatre de Rozier and five others Bowl was overloaded, and the flight ended not so well, as the previous ones;. The most affected by the fall of the creator of the balloon.) However, the example the first balloon was very contagious. In many European countries have become enthusiasts with a passion to build the balloons and boldly rise to them in the air. In January 1785 the famous aeronaut Blanchard later flew across the English Channel from England to France, thus opening the era of air travel.

All later balloons is very little different from the ones that came up with the Montgolfier and Charles. In general, although the Montgolfier brothers first balloon manufactured, his real creator should be considered after all Charles, since it was his design was the most practical and comfortable. In addition, Charles invented the rope network covering the globe and transmit to it the weight load, invented the air valve and anchor, first applied the sand as ballast and adapted to determine the height of the barometer.

Subsequent aeronauts did not add anything of substance to the balloon model he created. Like Charles, they still use to fill the bowl cheap hydrogen. It is explosive, however, is low cost and has the largest lift (1 cubic meter creates lift 1, 2 kg). Helium, which is 40-50 times more expensive than hydrogen creates the lift force of 1, 05 kg. Heated to 100 degrees as the air lift is only 0, 33 kg. Therefore, when a hot air balloons with duty charliere have a volume 4.3 times that in addition they have to carry fuel to the burner. The large surface area of ​​the balloon contributes to a huge loss of heat.

Any balloon flight is subject to the law of Archimedes - lift carrier gas that fills the shell, there is a difference between the weight of the air displaced by the shell, and the weight of the carrier gas. The smaller the share of gas, that is, the easier it is, the greater the lift has a balloon. (From this it is evident that the greatest lifting force would have the balloon, having within its vacuum envelope. For the first time the idea of ​​such a balloon offered in 1670 a monk de Lana Terzi. This idea has not yet been carried out, but if it were possible to overcome the atmospheric pressure, which will be squeeze the ball with the power of 10 tons per square meter, it could well give your results.)

At high altitude, where the air pressure is lower, the gas inside the shell begins to expand, bursting shell and finally breaks it. To avoid this, the first balloonists were forced to leave the open tube through which hydrogen is filled balloon (appendix). Going up, the balloon "squeezed out" of the appendix itself through excess gas. The shell therefore not threatened rupture, but with the gas leak reduced lift the balloon. It was necessary to facilitate the gondola, dropping ballast.

Boarding the balloon has always been dangerous. To make it less risky, Charles has supplied his ball several safety features. In an emergency, he provided a breaking device used to quickly discharging gas. Usually, wishing to go down, aeronaut let gas slowly through a special valve, but windy weather there was great danger that the balloon with a gondola would drag on the ground, so before touching the ground, passengers, pulling the rope, opened a large hole for the gas outlet. To reduce the shutter speed used guide-rope - thick rope length of 60-100 meters, which is dumped before landing. When you touch the guide-rope earth balloon weight decreased the weight of the guide-rope, located on the ground and the descent slowed somewhat. Maneuvering ballast gas valve and the guide-rope, experienced balloonists could quite successfully adjust altitude, take off and land. With regard to the flight direction, the aeronaut was here at the mercy of air currents. All attempts to control the balloon flight using wings, oars or propellers driven by a man, proved ineffective.

Largely as a result of the practical benefits of aeronautics, given the enormous costs of it (especially in the era of airships hobbies, which came in the first third of the XX century), it has always been negligible. But we should not be judged on this remarkable conquest of the human mind only in terms of practical benefits. The balloon first gave people the opportunity to get off the ground and soar to the clouds like a bird; he granted the centuries-old dream of human flight. Therefore its creation must be placed in some of the greatest of human inventions.

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