Dr. Page tells the full story of the discovery and development of radar, the most valuable weapon of World War Two and one of the marvels of our technological age. He starts with the accidental discovery of radar when in 1922 A.H. Taylor and L.C. Young noticed that ships on the Anacosta River interrupted radio transmission and follows the development of pulse radar to its present applications in navigation, weather forecasting, astronomy and other technical fields. Woven into the story is a clear explanation of radar equipment and the physical principles involved.