Christiaan Huygens

Christiaan Huygens (14 Apr 1629 — 8 July 1695) was a renowned Dutch mathematician, physicist, astronomer, music theorist and inventor. Huygens began researching 31-equal temperament and using logarithms to calculate string lengths and interval sizes as early as 1661. Christiaan Huygens described his 31-tone system comprehensively in two manuscripts, Lettre Touchant le Cycle Harmonique (Rotterdam, 1691) and Novus Cyclus Harmonicus (published posthumously in Leiden, 1724).