BALLOON

a bag made of light and strong material—(e.g.) silk—and_ filled with a gas.so as to rise and float in the air, which it does when the weight of the whole is le than the weight of an equal volume of air. In medizval times various suggestions were made by philosophers and others to enable metal spheres and other ve els to float in the air; but the first balloon was invented in 1782 by the brothers Joseph and Jaques near Lyons, who inflated a paper bag over a fire with smoke so that it ascended into the air. They reproduced this experiment on a larger scale, and were imitated in Paris by Charles and the brothers Robert in 1783, who, however, substituted hydrogen gas as an inflating agent. In that year the Montgolfiers carried out their famous experiment before the king and queen at Versailles, sending up a large decorated balloon inflated with smoke and heated air (it was later ascertained that not the smoke, as the Montgolfiers supposed, but the lighter heated air was the agent that enabled their balloons to rise), to which was attached a cage carrying a cock, a duck, and a sheep, which were found to be uninjured when the balloon descended. In 1783, also, the first human being, de Rozier, ascended in a captive, and later in a free, fire-balloon; while only a few days later Charles, who invented the valve, netting, and other acce ories, ascended in @ balloon inflated with hydrogen. ‘The first person in Britain -to rise in a balloon was Tytler, who ascended at Comely Gardens, Edinburgh, in 1784, in a fire-balloon constructed by himself, some days before the first ascent by the well-known Lunardi, at London. In 1785 the English Channel was first cro ed in a balloon by Blanchard and Jeffries, and in 1836 another famous balloon voyage was made by Holland, Mason, and Green, from London to Weilburg, in Na au, about 500 m., in 18 hours. In 1912 Bienaimé made a voyage in a balloon from Stuttgart, Germany, to near Moscow, Ru ia, a distance of nearly 1,362 m. As early as 1784 the balloon was employed for making scientific observations, and between 1862 and 1866 numerous ascents were made by Glaisher for the purpose of making barometrical and thermometrical observations, collecting air at different altitudes for analysis, etc., on behalf of the British A ociation—ascending on one occasion to a height of 37,000 ft. Balloons and kites are much used for meteorological experiments (See Barton Sonpve), either carrying pa engers to make observations or merely sent up with instruments attached. From beginning of 19th cent. down to Franco-Pru ian War (1870-1) balloons _ were used for m g reconnai ances in war; in Franco-Pru ian War for keeping up communication between Paris and the provinces. These services are now performed by dirigible balloons and aeroplanes. Captive Balloons are employed for directing the fire of artillery. For later developments see DrriciBiEs under AERONAUTICS.