Sir William Henry Bragg (1862-1942), British physicist and Nobel laureate, born in Wigton, Cumberland, England, and educated at King William's College and at Trinity College, University of Cambridge. He was Cavendish Professor of Physics at the University of Leeds between 1909 and 1915. Bragg and his son Sir William Lawrence Bragg shared the 1915 Nobel Prize in physics—the only father-son team to win the Nobel Prize. Both also shared in other honors for their pioneer work in the study of crystal structure by measurement of X-ray diffraction. From 1915 to 1923, Sir William Henry, who was knighted in 1920, held the chair of physics at the University of London. During World War I, he headed a research group that invented the hydrophone, an instrument used for detection of submarines.