age ~75
from North Ogden, UT
John Hadley (16 April 1682 14 February 1744) was an English mathematician, inventor of the octant, a precursor to the sextant, around 1730. He was born in
John Hadley (1731-5 November 1764) was a British chemist and physician. John Hadley was appointed in 1756 as the fourth Professor of Chemistry at Cambridge