18th Century Technology
The first hot air balloons that sailed over Europe during the 18th century were invented by two papermakers, Joseph and Etienne Motgolfier.  Made of paper and linen bags, the balloons were fueled by straw fires.  The brothers believed the burning created a gas which they called Montgolfier Gas.  However, later discoveries proved that the balloons rose because the heated air inside was lighter than the surrounding air.  These balloons were considerered dangereous because they stayed aloft only as long as a fired continued to heat the trapped air.  Hydrogen was discovered in 1766, but was not used in a balloon until August 27, 1783. French physicist, J.A.C. Charles launched a varnished silk bag fueled by hydrogen in Paris.  Measuring 13 feet in diameter, the balloon rose 3,000 feet and landed about 15 miles outside of Paris.  The controls that were featured in these round balloons were the top valves to release gas and the sand ballasts in the baskets to control the weight.