He became a Clerk Maxwell Scholar and entered Trinity College, Cambridge,[3] where he became a research student at the same time as Ernest Rutherford.

During World War I, he researched, at Woolwich, wireless methods for the Royal Naval Air Service.

Bleaney recounts an occasion when Townsend gathered together all the demonstrators and proceeded to refute both quantum mechanics and relativity.

Between the two world wars, Townsend led an effective small group of researchers, often Rhodes scholars, of whom some became distinguished physicists.

He had refused to support the war effort by teaching service-men, and the university appointed a visitorial board.

[5] John Townsend spent his retirement in Oxford, where he died in 1957 in the Acland Nursing Home.