Letter from P G [Perley Gilman] Nutting, Department of Commerce and Labor, Bureau of Standards, Washington, to [Joseph] Larmor Nutting thanks Larmor for the biography of Lord Kelvin, complimenting him on his appreciative understanding of Kelvin's 'stupendous'; life's work. Nutting has been examining a number of symmetrical composite lines in the spectra of hydrogen, the alkali, and related metals. These may be double, quadruple, or sixtuple depending upon intensity. He cannot think of any vibrating system for which such an emission spectrum would be possible and he asks for Larmor's thoughts. 1 August 1908