Hot Air Balloon

 A hot air balloon is a type of aircraft. It is lifted by heating the air inside the balloon, usually with fire. Hot air weighs less than the same volume of cold air , which means that hot air will rise up or float when there is cold air around it, just like a bubble of air in a pot of water. The greater the difference between the hot and the cold, the greater the difference in  density, and the stronger the balloon will pull up.

 The first hot air balloon to carry a person was made by the Montgolfier brothers.