Joseph John Thomson (1856-1940)

Biography of Joseph John Thomson

  • Joseph John Thomson

    Portrait of Joseph John Thomson, 1924

    Credit: Royal Institution


Ri positions

  • Professor of Natural Philosophy, 1905-1920
  • Honorary Professor, 1921-1940

Born in Manchester, he was educated privately before studying at Owens College and the Mathematical Tripos at Trinity College, Cambridge. He was second wrangler (meaning he was the second-highest scoring student in his class) in 1880. He was elected a Fellow of his college and began research in the theory of electricity following on from the work of Maxwell.

In 1894 he succeeded Lord Rayleigh as Professor of Experimental Physics at the University of Cambridge, a position he held until 1919. This involved running the Cavendish Laboratory which he established as a major research school in physics. In 1897 he discovered the particle later named the electron, the existence of which was first announced at a Friday Evening Discourse at the Ri. Thereafter he worked on developing a theory of matter.

Thomson won the Nobel Prize in 1906 for his studies of electrical conduction through gases, which he began following Wilhelm Roentgen's discovery of X-rays in 1895.

During the Great War Thomson was an active member of the Admiralty Board of Invention and Research and after the war played a major role in establishing the Department of Scientific and Industrial Research. He was President of the British Association in 1909 and was appointed Master of Trinity College in 1918 which he held until his death on August 30, 1940.