John Jeffries a letter he dropped from the balloon during his historic flight, considered the oldest piece of airmail in existence. He fled to Halifax, Nova Scotia in 1776 and later to England 1779, and was employed by the Crown during this time. In 1785, Jeffries and Jean-Pierre Blanchard crossed the English Channel in a balloon, becoming the first human beings to cross the Channel by air. Jeffries lived in England from 1779 to 1790. Despite being named in the Massachusetts Banishment Act, he returned to private practice in Boston, staying there until his death in 1819. His son John Jeffries II
Hot air balloon Montgolfier brothers, and had its first public demonstration on 4 June 1783 with an unmanned flight lasting 10 minutes, followed later that year with manned flights. The 1785 Rozière balloon, a type of hybrid balloon, named after its creator, Jean-François Pilâtre de Rozier, has a separate cell for a lighter than air gas (typically helium,) as well as a cone below for hot air (as is used in a hot air balloon) to heat the helium at night. Hydrogen gas was used in the very early stages of development but was quickly abandoned due to the obvious danger of introducing