Alongside Copernicus, Tycho Brahe, Galileo Galilei, and Johannes Kepler, the Toggenburg native Jost Bürgi is one of the great Europeans of the Early Modern period and a pioneer of modernity. As a clockmaker, he developed the world's first second clock and the scientific measurement of the second; as a mathematician, he invented logarithms and algebraic methods; as an instrument maker, he constructed proportional compasses and triangulation devices, a novel sextant, and intricately designed celestial globes. As the Imperial Court Clockmaker, he influenced the physics of the world when he helped his friend Kepler in Prague to initiate the Keplerian Revolution in 1609. As Fritz Staudacher reveals in a comprehensive and richly illustrated biography, Kepler benefited from Bürgi's calculation methods, astronomical observations, second clocks, and sextants to an extent that remains unknown to this day.