John Jeffries John Jeffries John Jeffries (5 February 1745 – 16 September 1819) was a Boston physician, scientist, and a military surgeon with the British Army in Nova Scotia and New York during the American Revolution. He is best known for accompanying Jean-Pierre Blanchard on his 1785 balloon flight across the English Channel. Born in Boston, Jeffries graduated from Harvard College and obtained his medical degree at the University of Aberdeen. Dr. Jeffries played a large role in the trial for the Boston Massacre as a witness for the defense. He was the surgeon for Patrick Carr, who was one of the
Hot air balloon an open flame near the gas. All modern Roziere balloons now use helium as a lifting gas. Solar balloons are hot air balloons that use just solar energy captured by a dark envelope to heat the air inside. Hot air balloon can be steered to a limited degree by changing the altitude of the flight. Wind in the northern hemisphere tends to turn right due to coriolis effect as the altitude increases. To help ensure the safety of pilot and passengers, a hot air balloon may carry several pieces of safety equipment. To relight the burner if the pilot light