Donna Harrington, age 8, of Portland, Me., for her question.:
WHO INVENTED THE BALLOON?
Leonardo da Vinci, the famous artist scientist who lived from 1452 until 1519, tried to build a bird machine. It didn't work because he didn't consider the tremendous strength of the muscles that give the wings of birds their power. A machine strong enough to fly as the birds do would be too heavy for man's muscles to work.
In the 18th century two French brothers named Jacques Etienne and Joseph Michel montgolfier were probably the first to fly. They had noticed how scraps of paper would soar up a chimney over an open household fire. They fashioned bags from paper and placed them over dishes filled with burning charcoal.
The brothers Montgolfier found that their small bags of paper would rise to the ceiling, and then drop to the floor as the air inside cooled. Success with these simple experiments gave them courage to try large balloons filled with hot air.
On June 5, 1783, the brothers staged their first large balloon ascension from Versailles in France. Later they sent chickens and sheep aloft in their balloons and finally en Nov. 21, 1783, Pilatre de Rozier and the Marquis d'Arlandes ascended in one of the Montgolfier balloons that was fastened to the ground by a long rope.
The two Montgolfier brothers continued their experiments and made many exhibition flights with great success in the years that followed.
The first balloons used by man were made of paper and filled with hot air. Later came balloons made of rubberized cloth.
There are two types of lighter than air balloons used today: those made of elastic materials, such as natural rubber, or a synthetic, such as neoprene; and those made of non elastic materials, called constant volume balloons.
Balloons in use today include one made of neoprene and filled with hydrogen that is commonly used by weather stations. It is six feet in diameter on the ground and carries three pounds of equipment. It expands as it rises because the pressure outside the balloon. becomes less than. the pressure inside. Some reach heights of 20 miles and get as large as 90 feet in diameter before bursting. The equipment drops to the ground by parachute.
Modern blimps are another type of lighter than air craft. The helium filled cigar shaped crafts have fine safety records in commercial flights and are used for sightseeing and advertising. During World War II blimps were also used effectively for anti mine work, photography, search, observations, shipping control and rescues at sea and en land.