Who discovered Fluorine?

A Pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. In 1656 Christiaan Huygens invented the Pendulum Clock, the pendulum clock was the world’s most precise timekeeper, accounting for its widespread use. Throughout the 18th and 19th centuries pendulum clocks in homes, factories, offices, and railroad stations served as primary time standards. Huygens has been called the first theoretical physicist and the founder of mathematical physics.