THOMSON, SIR JOSEPH JOHN (1856— ), British physicist, was born on Dec. 18, 1856 near Manchester, and edu cated at Owens college, Manchester, and at Trinity college, Cambridge, where he was elected a fellow in 188° and became lecturer in physics in 1883. In 1884 he was appointed Cavendish professor in the University of Cambridge and in 1919 research professor, holding in addition from 1905-18, the professorship of physics at the Royal Institution, London, and subsequently an honorary appointment. He became master of Trinity college in 1918. He developed at Cambridge a great research laboratory, which attracted workers from many countries, and carried out there epoch-making investigations on the conduction of electricity through gases, the determination of the charge and mass of the electron, and analysis by means of positive rays. He became F.R.S. in 1884, and was president in 1915. He was knighted in 1908, and was the recipient of many awards and honours, includ ing i.he O.M. During the World War he assisted various Govern
ment departments in an advisory capacity. (See GAs.) In addition to a large number of publications in the Proceedings of the Royal Society and The Philosophical Magazine, he published A Treatise on the Motion of Vortex Rings (1883) ; The Application of Dynamics to Physics and Chemistry (i888) ; Recent Researches in Electricity and Magnetism (1893) ; Elements of the Mathematical Theory of Electricity and Magnetism (1895, 5th ed. 1921) ; The Discharge of Electricity Through Gases (1898) ; The Conduction of Electricity Through Gases (19o3) Rays of Positive Electricity and Their Application to Chemical Analysis (1913, 2nd ed., 1922) ; The Electron in Chemistry, five lectures delivered at the Franklin Institute, Philadelphia (1923) ; and, with Professor Poynting, a number of general text-books on physics.