The third man: Charles Drummond Ellis, 1895-1980

Abstract

The Fellows of the Royal Society have a tradition of writing expositions of their work which rapidly attain the status of classics. Newton’s Principia, Darwin’s Origin of Species , Maxwell’s Theory of Electricity and Magnetism, Rutherford’s Radioactive Transformations , and Dirac’s Quantum Mechanics all served to define a field which their authors had played a major role in establishing, and as a source of knowledge and inspiration for succeeding generations. Rutherford’s book went through two metamorphoses before reaching its final form as Radiations from Radioactive Substances by Rutherford, Chadwick and Ellis (hereafter referred to as RCE). During the early 1930s, it was the principal source for all aspiring nuclear physicists, including Fermi's group in Rome and a whole generation in America. It thus, inadvertently, contributed to the erosion of the overwhelming dominance of the Cavendish Laboratory in the subject. It was often referred to as the ‘Bible’ of nuclear physics, but at least from 1932, ‘Old Testament’ might have been more appropriate. It is firmly based on the proton-electron model of the nucleus and the ‘new mechanics’ makes only a tentative appearance. Nevertheless it is a true masterpiece, clearly and elegantly written, full of incisive summaries and insights, and giving a remarkably faithful and complete picture, from an experimental viewpoint, of nuclear physics as it was around 1930.