Sir Richard Tetley Glazebrook (18 September 1854 – 15 December 1935) was an English physicist. Education and early career Glazebrook was born in West Derby, Liverpool, Lancashire, the son of a surgeon. He was educated at Dulwich College until 1870, Liverpool College from 1870 to 1872, and Trinity College, Cambridge, from which he graduated in Mathematics in 1876 and of which he was elected a fellow in 1877. He studied physics under James Clerk Maxwell and Lord Rayleigh at the new Cavendish Laboratory and, in 1880, was appointed a demonstrator at the laboratory. The following year (1881), he was also appointed a college lecturer in mathematics and physics and a university lecturer in mathematics. His research focused on electrical standards and aviation. When defining electrical standards for the unit of resistance, the British Science Association were trying to determine what length a mercury column should be, to express the absolute value of the Ohm. A number of different values had been obtained over the years and Glazebrook determined the value at 106.3 cm. Despite skepticism of mercurial standards this was the International value agreed on later by the 1893 Chicago conference. Later career He hoped to succeed Rayleigh as Cavendish Professor of Physics in 1884, but was surprisingly (given that he was also Rayleigh's choice) passed over in favour of Sir J.J. Thomson, which was a great disappointment to him. He was, however, appointed Assistant Director of the Cavendish in 1891 and Bursar of Trinity College in 1895. In 1898, he was appointed Principal of University College, Liverpool. In June 1899, however, he left to become first Director of the National Physical Laboratory (NPL) in Teddington. During the First World War, he chaired the government's Advisory Committee for Aeronautics, located at the NPL, under the presidency of John Strutt, Lord Rayleigh. He held his post at the NPL until his retirement (largely due to friction with the Department of Scientific and Industrial Research) in 1919, successfully establishing the NPL as a world leader in physics research. Retirement Following his retirement, he moved back to Cambridge and edited the Dictionary of Applied Physics. From 1920 to 1923 he was Zaharoff Professor of Aviation and Director of the Department of Aeronautics at Imperial College, London. He remained on the General Board of the NPL and chaired the Executive Committee from 1925 to 1932. Honours and awards In 1882, he was elected a