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
Free Life (balloon) balloon in Europe. The "Free Life" attempt was the first use of a Roziere style balloon for an Atlantic attempt, built by Mark Semich, using a combination of helium and hot air. Below the spherical helium gas cell is a conical sleeve where air can be heated by burners in the same way as a normal hot air balloon. By varying the hot air temperature, altitude can be maintained without having to release helium or to drop ballast. The burners are principally used to compensate for the lack of solar heating at night. After four years of planning and postponements,