Hadley, JOHN

F.R.S., 1682-1744. English inventor of a quadrant and a reflecting telescope. Hadley's Principle. Law a umed by George Hadley 1744, according to which a body projected meridionally north (or south) gradually deviates to the east (or west) because it retains its eastward velocity while pa ing over regions that move with le (or greater) eastward diurnal rotatory speed. On this principle Hadley based an explanation of trade winds and anti-trades, whose fallacy was first exposed by Ferrel 1856.