Mechanical clocks are timekeeping devices that use gears and springs to measure time. They operate based on the principles of mechanics, where a wound spring or a falling weight drives the movement of gears. This movement is regulated by an escapement mechanism, which allows the clock to keep accurate time. These clocks can be found in various forms, including wall clocks, grandfather clocks, and pocket watches. Unlike digital clocks, mechanical clocks do not rely on electricity; instead, they require manual winding or are powered by weights. Famous examples include the Pendulum Clock invented by Christiaan Huygens in the 17th century, which greatly improved timekeeping accuracy.