Circa 1694 Étienne Loulié, a musician who had recently collaborated with mathematician Joseph Sauveur on the education of Philippe, Duke of Chartres, was asked by Chartres to work with Sauveur on a scientific study of acoustics sponsored by the Royal Academy of Science. To measure scientifically the number of beats per second caused by different dissonances, they used the "seconds pendulum" invented by Galileo earlier in the century. It doubtlessly was these experiments, on top of his lessons to Chartres, that gave Loulié the idea for his chronomètre, a precursor of the metronome.