John William Strutt, 3rd Baron Rayleigh (1842-1919)

Born in Maldon, he briefly attended both Eton College and Harrow School, but because of ill health was mostly educated at private schools. He studied the Mathematical Tripos at Trinity College, Cambridge, and was senior wrangler (the highest-scoring graduate) in 1865. He was elected a Fellow of Trinity, a position he held until he married in 1871.

After spending some time in Greece and Egypt for medical reasons, he returned to scientific research, including psychic phenomena. His first major work was on Maxwell's theory of electro-magnetism which he rendered somewhat more comprehensible. In 1879 he succeeded Maxwell as Cavendish Professor at the University of Cambridge, a position that he held until 1884 when he retired to his country house, Terling Place, where he built a private laboratory.

In 1894 he and William Ramsay discovered argon, for which they won the Nobel Prize ten years later. From 1896 until 1911 he was scientific adviser to Trinity House, the English and Welsh lighthouse authority (a position Michael Faraday had also held from 1836 to 1865). Rayleigh was made president of the British Association in 1884 and played a major role in the founding of the National Physical Laboratory in the late nineteenth, early twentieth century.

Further reading:
Oxford Dictionary of National Biography
nobelprize.org