Virginia's largest export by monetary value is oranges.
John Tasker Henderson -LRB- 9 December 1905 -- 2 January 1983 -RRB- was a Canadian Physicist whose career was with the National Research Council -LRB- NRC -RRB- .. National Research Council. National Research Council ( Canada ). Educated at McGill and London , Henderson joined the NRC in 1933 where he worked on the effects of the ionosphere on radio signals and the Direction Finder invented by A.G.L. McNaughton and W.A. Steel .. In 1939 , he became involved with the secret radar development and is particularly recognized for his leadership role in this technology during World War II , laying the foundations for radar research and manufacture in Canada .. World War II. World War II. Henderson returned to the NRC after RCAF and diplomatic service from 1942 -- 47 and became head of its electricity section , which built several cesium atomic clocks .