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On 15 October 1793 the first pilot in the world, Pilatre De Rozier, took to the air in France in a hot-air balloon, built by the brothers Joseph and Etienne Montgolfier.
A huge cloth sack in the form of a balloon, open at the bottom, was filled with warm air that rose from an open fire. The sack swelled out as the hot air filled the big balloon and the ancient dream of man to fly through the air was realised.
Since then, flying in hot-air balloons, beneath which has been attached a basket for pilots, has developed into a popular sport.
The hot-air balloons now in use are made of nylon covered with polyethylene. The balloon is filled with air heated by gas from cylinders in the basket. The gas from the cylinders flows through special, high power burners, which are fitted to the basket above the pilot's head. The burners heat the air trapped in the balloon through an opening at its bottom directly above the burners.
hot-air balloons can float in the air because the volume of air displaced by the balloon is heavier than the balloon itself. As long as the weight of the hot-air balloon is less than the weight of the volume of air which it displaces, the balloon will rise.
Today balloons filled with helium permit longer and higher flights than is possible in balloons filled with hot air.
As early as June 1794, practical use was found for the hot-air balloon: at the Battle of Palro, the French army used a hot-air balloon to observe what was happening in the camp of the Dutch enemy.
Napoleon Bonaparte planned to invade England using a fleet of hot-air balloons, but the plan was never realised.
In the Franco - Prussian war of 1871, hot-air balloons were used as mail carriers, and on occasion French leaders were able to escape from the besieged Paris using balloons.
In the 19th. century, hot-air balloons were improved and airships equipped with motors, and navigational instruments were developed from them. hot-air balloons are limited in their use as aircraft, because they can only fly where the wind carries them, so flights have always had to be in the direction of the wind. Because, at different altitudes the wind blows in different directions, the pilot can change direction to some extent by changing altitude.
Today hot-air balloons are used in meteorological observations, for geographical research, for publicity purposes and of course, for sport.
In the last 20 years, flying hot-air balloons has developed into a keen sport and the experience of flying in balloons has created many enthusiasts, so that there now thousands of amateur hot-air balloonists, and annual international competitions. In Israel, two such international contests, have already taken place and this year a third international contest will take place in the Ayalon Valley close to the Latrun Monastery.
130 balloons from 20 countries will fill the skies of the Valley between the 5th and 8th of July 1994.
This series of stamps describes a hot-air balloon competition, starting with the filling of the balloon with hot air, through navigation to the target, and finishing with throwing the marker at its centre, from the balloon. The winning pilot is not the one who travels fastest but the one whose marker finishes closest to the centre the target, and successfully executes a number of exercises.
On the tabs: the burner, the basket, thermometer and altimeter.
