Britain's Atomic Expert.Professor Sir John Cockcroft. C.B.E., F.R.S.The Atomic Pile - This is a general view of the face of Gleep, the first atomic pile to be built at Harwell. There is a second pile constructed in Great Britain and is far larger than the firs. It was started in August 1947 and began working in July 1948.On July 17, 1948, the cloak of secrecy was lifted from the activities of Britan's Atomic Energy Reserach Establishment at Harwell, near Didcot, in Berkshire. November 4, 1949. (Photo by British Official Photograph).