Two brothers, Jacques and Joseph Montgolfier, and a scientist, Pilatre De Rozier. The envelope is the fabric which holds the air; the burner is the unit which shoots the heat up inside the envelope; the basket is where the passengers and pilot stand. Air is made up of molecules of nitrogen, oxygen, and other gases which move around at incredible speeds. As air heats up, the molecules speed up and push harder against their surroundings. When vapor molecules are introduced into that volume of dry air, the number of air molecules in the volume must decrease by the same number. Hence the mass per unit volume of the gas-its density-decreases.

 

A typical commercial flights can reach anywhere from 500 to 3,000 feet altitude above ground level. The altitude record for hot air balloons is 65,000 feet. Helium balloons using specialized equipment have exceeded 100,000 feet in altitude. The speed at which a balloon moves depends on the speed of the winds at a given altitude.

 

Cool weather is always preferred to hot weather, so spring and autumn are ideal. Regardless of the time of year, most pilots prefer to fly either just after dawn or just before dusk, since these times offer cooler air and the calmest and most favourable wind conditions for hot air ballooning. Furthermore, the heat propelled by the burner is relative to the outside air temperature, so flying in cooler temperatures requires less propane gas.