English physicist born in lot in 1852 and died in Birmingham in 1914, which showed the pressure exerted by radiation.
After studies in Manchester and at Trinity College, Cambridge, was on Owens, Professor of the College Masony College lab assistant professor of Physics of the University of Birmingham, where he served until the end of his days. He inquired about the electromagnetic waves and Maxwell's theory. The vector of Poynting, described in 1884, express the direction and magnitude of the energy flow of the electromagnetic field. He noted the pressure exerted by radiation, and said that astronomically it could have a significant effect. He made a determination of the gravitational constant of Newton scale method by Cavendish, and obtaining a very similar to the modern accepted value. His works are The mean density of the Earth (1894), A textbook of Physics (1899, together with J. j. Thomson), The properties of matter (1902) and Unscientific materialism.