Sir William Henry Bragg

(1862–1942) British physicist, who with his son Sir William Lawrence Bragg (1890–1971), was awarded the 1915 Nobel Prize for physics for their pioneering work on X-ray crystallography. He also constructed an X-ray spectrometer for measuring the wavelengths of X-rays. In the 1920s, while director of the Royal Institution in London, he initiated X-ray diffraction studies of organic molecules.