from memory, he was permitted to read his inaugural lecture. Circa 1694, Sauveur began working with Loulié on "the science of sound", that is, acoustics. As Fontenelle put it, Sauveur laid out a vast plan that amounted to the "discovery of an unknown country", and that created for him a "personal empire", the study of "acoustical sound" (le son acoustique). But, as Fontenelle pointed out, "He had neither a voice nor hearing, yet he could think only of music. He was reduced to borrowing the voice and the ear of someone else. and in return he gave hitherto unknown demonstrations to musicians." The Duke of Chartres did everything he could to make the undertaking successful. Sauveur's work, continued Fontenelle, resulted in "a new musical language that was more convenient and more broad, a new system of sounds, an unusual monochord, and échomètre, fixed sound [le son fixe, that is, absolute frequency], the nodes of undulating strings. [...] This pushed him all the way to the music of the ancient Greeks and Romans, the Arabs, the Turks and the Persians." Sauveur is known principally for his detailed studies on acoustics. Indeed, he has been credited with coining the term acoustique, which he derived from the ancient Greek word ακουστός, meaning "able to be heard". His work involved researching the correlation between frequency and musical pitch, and – putting Fontenelle's statements in modern terms – he conducted studies on subjects such as the vibrating string, tuning pitch, harmonics, ranges of voices and musical instruments, et al. He also created a measure of intervals concerning the octave. Though Marin Mersenne's 1637 theories are correct, his measurements are not very exact, and his calculation of Mersenne's laws was greatly improved by Sauveur through the use of acoustic beats and metronomes. The following are some of the terms Sauveur used as logarithmic divisions: méride: 1/43 part of an octave eptaméride (or heptaméride): 1/301 part of an octave, or 1/7 of a méride; this term would later be known as a savart. demi-heptaméride: 1/602 part of an octave; 1/2 of an eptaméride. decaméride: 1/3010 part of an octave; 1/10 of an eptaméride Also 1/55 of an octave would become known as a "Sauveur comma". In 1696, Sauveur had been elected to the French Royal Academy of Sciences and most of his work on acoustics was therefore done under its aegis. He soon ran into what proved