Schuster, Sir Arthur, 1851–1934, English physicist, b. Germany. At Owens College, Manchester Univ., he was professor of applied mathematics (1881–88) and professor of physics (1888–1907). He is known for his work in spectroscopy (he was a leading authority in the field), electricity in gases, terrestrial magnetism, radiometry, calorimetry, and the mathematical theory of periodicity. In 1875 he led the Royal Society's expedition to Siam (now Thailand) to observe the solar eclipse. He was knighted in 1920. Among his works are An Introduction to the Theory of Optics (1904) and Biographical Fragments (1932).