Diagrams, harmonic analysis by G H [George Howard] Darwin Three diagrams, labelled figures 1-3, showing a series of parallelograms and trapeziums related to Darwin's methods of harmonic analysis. Includes a note to the engraver. Subject: Physics Prints of these diagrams were published in volume 52 of the Proceedings of the Royal Society alongside the paper 'On an apparatus for facilitating the reduction of tidal observations'. 1892