Duplicate material (e.g. typescripts and printed copies of Ryle's Nobel Lecture) has not been retained. The 1974 Nobel Prize for Physics was awarded to Ryle and Antony Hewish 'for their pioneering research in radio astrophysics: Ryle for his observations and inventions, in particular of the aperture synthesis technique, and Hewish for his decisive role in the discovery of pulsars'. From Acc and Acc 1183. See also RYLE L.19.