Hot air balloons are large, spherical, made of silk, rubber, or other non pourous materials. There are two kinds of hot air balloons. One is manned that carrys one or more people a suspended basket. Two is unmanned, that carrys instruments used to measure and record observations or tests. There are four main parts of the hot air balloon, there is the envelope, the skirt, the gas burner, and the basket. As shown below.

  In 1709 Bartolomea de Gusmao demonstrated a model hot air balloon at the court of King John V of Portugal. On August eighth 1709 Gusmao presented his model for examination by the king, Queen Maria Anna, the Papal Nuncio, and Cardinal Conti. Also examining were princes, nobles, diplomats, and other court members. Gusmao recorded that the balloon went to twelve feet before two of the examiners stopped him for fear that he would set the curtains on fire. Shortly after Etienne and Joseph Montgolfier originated the first hot air balloon. Hot air balloons have been around for two hundred years, and the first successful manned balloon flight took place in 1783.
                                                                    The elements of a hot air balloon
    Phlogiston, later called hydrogen, was the first gas to be used in hot air balloons. Henry Caveddish discovered this gas, weighing fifty-three pounds per one thousand cubic feet. Jaques A.C. Charles launched an unmanned phlogiston - filled balloon in 1783. Now, hot air balloons are filled with hydrogen or helium. The advantage of having helium filled balloons is that it is nonflammable. The advantage of having hydrogen filled balloons is that it is lighter than helium. The most modern hot air balloons are filled with propane gas. The advantages of having popane - filled balloons are that it is simple, inexpensive, safe, and light source of hot air.
                                                                         The uses of a hot air balloon
    There are many uses of hot air balloons. These include military use in World War I, it is raced for sport, observation points, to deliver important messages, and just for pleasure. Hot air balloons are also used for scientific use. Some examples are J.A.C. Charles made recordings of air temperature and barometric pressure in 1783. Jean Pierre Blanchard and Dr. Jeffries made similar recordings. In 1804 Lussac made two flights to see how earths magnetic field changed with increasing altitude. Unmanned balloons have meteorological uses, such as, wind direction and speed, and transmitting data to earth.
 
 

 

Kathleen Sweeney and Ashley Smith  4th hour Science with Briggs