Thomson's cathode ray tube, 1897.
© Science Museum / Science & Society Picture Library
This is one of the original vacuum tubes used by the Cambridge profesor of physics John Joseph Thomson (1856-1940) to discover the electron in 1897. Thomson's work contributed enormously to our understanding of the atomic structure of matter, leading to the research fields of atomic and nuclear physics, and marking the birth of the modern electronic age. An enthusiastic and ambitious theoretician, Thomson was known to be an inexpert experimenter, but the results of his work with simple table-top apparatus have proved momentous.