John Jeffries (1796-1876) was an ophthalmic surgeon and co-founded the Massachusetts Charitable Eye and Ear Infirmary. 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
Balloon of motion, the balloon is propelled forward. This is the same way that a rocket works. Balloons filled with hot air or a buoyant gas have been used as flying machines since the 18th century. The earliest flights were made with hot air balloons using air heated with a flame, or hydrogen as the lifting gas. Later, coal gas and later still helium were used. An unpowered balloon travels with the wind. A balloon which has an engine to propel it is called a dirigible balloon or airship. Angioplasty is a surgical procedure in which very small balloons are inserted